National Climate Report - April 2017
- Climate Highlights — April
April Average Temperature Departures
April Percent of Average Precipitation
- The average temperature for the contiguous U.S. was 53.8°F, 2.7°F above the 20th century average during the month of April. This was the 11th warmest April on record for the Lower 48 and warmest April since 2012.
- Locations from the Mississippi River to East Coast were much warmer than average. Delaware, Maryland, New Jersey, North Carolina, Ohio, Pennsylvania, West Virginia, and Virginia each had their warmest April on record. The average April temperature for Washington, D.C. was also record high at 63.8°F, 1.8°F warmer than the previous record set in 1994. Reliable temperature data for D.C. date back to 1872.
- Near- to below-average temperatures were observed across the Northwest, Great Basin, Northern Rockies and Northern Plains. For the third time this year, the Washington state monthly averaged temperature was below average.
- The Alaska statewide average temperature was 29.9°F, 6.6°F above average. This was the sixth warmest April in the 93-year record for the state. Above-average temperatures spanned Alaska during April, with much-above-average temperatures across the southern third of the state.
- The contiguous U.S. average maximum (daytime) temperature during April was 65.9°F, 2.4°F above the 20th century average, the 20th warmest on record. Above-average maximum temperatures were observed across the Southwest and Southern Plains and locations from the Mississippi River to East Coast. Twenty-two states had much-above-average maximum temperatures with maximum temperatures for Delaware and Maryland record warm. Below-average maximum temperatures were observed in the Northwest.
- The contiguous U.S. average minimum (nighttime) temperature during April was 41.7°F, 3.0°F above the 20th century average, the sixth warmest on record. Above-average minimum temperatures were observed for most locations across the country, with the exception of the Northwest, Great Basin, and Northern Plains. Much-above-average minimum temperatures were observed across the East, where 15 states from South Carolina to New Hampshire were record warm.
- During April there were 3,126 record warm daily high (989) and low (2,137) temperature records, which is more than three times the 962 record cold daily high (749) and low (213) temperature records.
- Based on NOAA's Residential Energy Demand Temperature Index (REDTI), April 2017 was zero and ranked as the lowest in the 123-year record for April, due to much-warmer-than-normal temperatures across the densely populated Midwest and Northeast.
- The April precipitation total was 3.43 inches, 0.91 inch above the 20th century average, making it the second wettest April in the 123-year period of record.
- Above-average precipitation was observed across a large portion of the nation, including much-above-average precipitation in the Northwest, Northern Rockies, Central Plains, Mid-Mississippi Valley, Mid-Atlantic and Great Lakes. Record precipitation was observed in parts of the Northwest, Southern Plains and Mid-Atlantic. North Carolina had its wettest April on record with 6.75 inches of rain, 3.22 inches above average. Below-average precipitation was observed in parts of the Southwest and Northern Plains.
- Several storm systems impacted the Southern Plains and Mid-Mississippi River Valley in late April with the precipitation continuing into May, resulting in widespread flooding across the region. At the time of this report's release, at least five fatalities were attributable to the flooding with significant impacts on agriculture.
- During April there were over 200 preliminary tornado reports, continuing an active tornado year. Large tornado outbreaks impacted the central and southern U.S. in early and late April resulting in eight tornado-related fatalities in Louisiana, South Carolina and Texas.
- Alaska had its second driest April on record with 0.92 inch of precipitation, 0.97 inch below average. Only April 1932 was drier with 0.84 inch of precipitation. Record and near-record dry conditions were observed across the central and eastern parts of the state. April is climatologically the driest month of the year for Alaska.
- According to the May 2 U.S. Drought Monitor report, 5.0 percent of the contiguous U.S. was in drought, down 9.2 percent compared to the March 28 values. This is the smallest drought footprint reported by the U.S. Drought Monitor since its inception in 2000. Drought improved across the Great Plains, Mississippi River Valley, interior areas of the Southeast, and Northeast. Drought worsened in the Southwest and across parts of the Southeast where several large wildfires burned in Florida and southern Georgia.
- Climate Highlights — year-to-date (January-April)
Jan-Apr Average Temperature Departures
Jan-Apr Percent of Average Precipitation
- The year-to-date average temperature for the contiguous U.S. was 43.7°F, 4.5°F above average. This was the second warmest January-April, behind the record of 44.7°F set in 2012.
- Above-average temperatures spanned the nation with only the Northwest being colder than average. Forty states were much warmer than average during January-April with 14 states record warm. Record warmth stretched from the Southern Rockies to Southeast and Midwest.
- The contiguous U.S. average maximum (daytime) temperature during January-April was 54.6°F, 4.2°F above the 20th century average, the third warmest on record. Above-average maximum temperatures were observed across the Southwest and from the Great Plains to East Coast. Thirty-six states had much-above-average maximum temperatures with maximum temperatures record warm for nine states across the South and Midwest. Below-average maximum temperatures were observed in the Northwest.
- The contiguous U.S. average minimum (nighttime) temperature during April was 32.7°F, 4.9°F above the 20th century average, the second warmest on record. Above-average minimum temperatures were observed for most locations across the country, with the exception of the Northwest. Forty-one states has much-above-average minimum temperatures with 18 states record warm.
- The year-to-date contiguous U.S. precipitation total was 11.46 inches, 1.99 inches above average. This was the fifth wettest January-April on record and wettest since 1998.
- Above-average precipitation spanned most of the West into the Great Plains and Great Lakes. Seven states in the West, three in the Great Plains and two in the Great Lakes had year-to-date precipitation totals that were much above average. Idaho had its wettest January-April on record with 15.17 inches of precipitation, 5.42 inches above average, and 0.12 inch above the previous record set in 1904. Below-average precipitation was observed in the Northern Plains, Northeast and Southeast.
- The U.S. Climate Extremes Index (USCEI) for the year-to-date was more than twice the average and the second highest value on record. The January-April USCEI in 2012 was slightly higher. On the national scale, extremes in warm maximum and minimum temperatures, one-day precipitation totals, and days with precipitation were much above average. The USCEI is an index that tracks extremes (falling in the upper or lower 10 percent of the record) in temperature, precipitation and drought across the contiguous United States.
- Regionally, the was record high for the Southeast, second highest for the Northeast, Upper Midwest, Ohio Valley, and South. In each of the regions above, extremes in both warm maximum and warm minimum temperatures were record or near record high. In the Southeast, the spatial extent of drought and one-day precipitation totals was much above average. In the Northeast, one-day precipitation totals were much above average. In the Upper Midwest, the spatial extent of wetness and days with precipitation was much above average. In the South, one-day precipitation totals were much above average. The West had its third highest CEI due to extremes in warm minimum temperatures, the spatial extent of wetness, one-day precipitation totals, and days with precipitation
These regional summaries were provided by the six Regional Climate Centers and reflect conditions in their respective regions. These six regions differ spatially from the nine climatic regions of the National Centers for Environmental Information.
- Northeast Region: (Information provided by the Northeast Regional Climate Center)
- The Northeast had its second warmest April on record with an average temperature of 50.5 degrees F (10.3 degrees C), 4.4 degrees F (2.4 degrees C) above normal. This was only 0.2 degrees F (0.1 degree C) behind April 2010, which is the warmest April on record. However, at the state level, this April was the warmest on record for Delaware, Maryland, New Jersey, and Pennsylvania and ranked among the top 10 warmest on record for the other eight states: Rhode Island and West Virginia, 2nd warmest; Massachusetts and New York, 3rd warmest; Connecticut and New Hampshire, 5th warmest; Vermont, 8th warmest; and Maine, 10th warmest. Average temperatures for the states ranged from 2.3 degrees F (1.3 degrees C) above normal in Maine to 5.6 degrees F (3.1 degrees C) above normal in Delaware. Fourteen of the region's 35 major climate sites had a record warm April.
- During April, the Northeast received 3.87 inches (98.30 mm) of precipitation, which was 106 percent of normal. Six states were wetter than normal, five were drier than normal, and one received normal precipitation. For all twelve states, precipitation ranged from 65 percent of normal in Delaware to 132 percent of normal in Rhode Island. New York had its 14th wettest April on record, while Rhode Island had its 17th wettest. Buffalo, New York, had its wettest April on record with 6.38 inches (162.05 mm) of precipitation. The previous record was 5.90 inches (149.86 mm) in 1961.
- The U.S. Drought Monitor released on April 6 indicated 11 percent of the Northeast was in a moderate or severe drought, with another 19 percent being abnormally dry. Abnormally dry and drought conditions continued to improve in the Northeast during the month. The region became free of severe drought for the first time since late June 2016. Moderate drought eased in Maine, Massachusetts, New York, most of New Hampshire and Vermont, and portions of Connecticut, Pennsylvania, and Maryland. Abnormal dryness eased in New Jersey and portions of northern and southern Maine, central New Hampshire, central Vermont, Massachusetts, southeastern New York, eastern Pennsylvania, north-central Maryland, and southeastern West Virginia. The U.S. Drought Monitor released on April 27 indicated 3 percent of the Northeast was in a moderate drought, with another 17 percent being abnormally dry. April average streamflow was near to above normal for most of the region, while groundwater levels ranged from below normal to above normal. Many reservoirs returned to near-normal levels, but several others remained below normal. The Massachusetts Water Resources Authority continued to urge customers to conserve water as the Quabbin Reservoir was at 82.1 percent of capacity on April 1, which was below normal. On April 20, Manchester, New Hampshire, officials lifted voluntary water restrictions that had been in effect since October 2016 as the city's water supply had returned to full capacity. According to an April 21 press release, all of Connecticut Water's reservoirs throughout the state were at 100 percent of capacity, so the water supply advisory was lifted. Aquarion's Bridgeport and Greenwich (Connecticut) reservoirs were at near to above-average capacity as of April 24 but its Stamford reservoir was still below-average capacity at 88.4 percent as of April 25. With improving conditions, drought declarations in several states eased. Eastern Maryland improved from a Drought Watch to normal status as of March 31. Effective April 1, the Connecticut River Valley and southeast Massachusetts improved to a Drought Advisory from a Drought Watch, while western Massachusetts improved to normal status from a Drought Advisory. On April 6, Mifflin and Union counties in Pennsylvania improved from a Drought Warning to a Drought Watch, while four other counties improved from a Drought Watch to normal status. As of April 12, the Drought Warning was lifted for 12 counties in New Jersey and the Drought Watch was lifted for four other counties, returning those 16 counties to normal status. Hunterdon and Somerset counties remained in a Drought Warning because the reservoirs that serve those areas remained below normal.
- On April 6, two weak tornadoes in Washington, D.C. and damaging winds in Maryland, Delaware, Pennsylvania, and New Jersey downed trees and caused structural damage. Up to 3 inches (76 mm) of rain led to flooding in parts of the region. Caribou, Maine, had 12 inches (30 cm) or more of snow on the ground for 132 consecutive days (November 30, 2016-April 10, 2017), which is the longest stretch on record and 12 days longer than the previous record set in 1968-69. A low pressure system produced severe thunderstorms and heavy rain in portions of the region on April 20. In western Pennsylvania, a weak tornado damaged trees and a home, while golf ball to hen egg-sized hail damaged vehicles. In western New York, flash flooding occurred. Buffalo received 1.95 inches (49.53 mm) of precipitation, making it the site's wettest April day on record. The previous record was 1.77 inches (77.96 mm) in 1903.
- For more information, please go to the Northeast Regional Climate Center Home Page.
- Midwest Region: (Information provided by the Midwest Regional Climate Center)
- April precipitation totals were above normal for a majority of the region, with the highest departures in southern Missouri at more than 300% of normal. Other areas with significantly above normal precipitation included the rest of Missouri along with portions of southern Illinois, northern Wisconsin, and Upper Michigan. On the other hand, areas in northern Minnesota and central Kentucky received less than half their normal April precipitation. Monthly precipitation totals ranged from less than 0.50 inch (13 mm) to over 15 inches (381 mm). Missouri's preliminary statewide average precipitation was 9.81 inches (249 mm), which would be the wettest April on record (1895-2017) for the state. Tecumseh, MO (period of record, 1942-present) received 17.48 inches (444 mm) of precipitation in April, breaking the previous monthly precipitation record of 14.43 inches (367 mm) set in 1957. Much of the significant precipitation in Missouri fell on April 29 and 30. Tecumseh received nearly half of its record-breaking monthly precipitation over this two-day period and a CoCoRaHS station in Houston, Missouri recorded a two-day total over 12 inches (305 mm). In addition to Missouri's record-breaking precipitation, Illinois, Michigan, and Wisconsin all had statewide averages for April precipitation that fell among their 10 wettest. More than 5 inches (13 cm) of April snow was reported in portions of northern Minnesota, northern Wisconsin, the U.P. of Michigan, and northeast Ohio. In Upper Michigan, some areas received over 10 inches (25 cm) during the month. The monthly snowfall totals were above normal in scattered areas across the upper Midwest, but below normal for most of the areas that had snow.
- April temperatures were above normal across a majority of the Midwest, with the exception of near-normal temperatures in portions of Minnesota, Wisconsin, and Iowa. In Indiana, Ohio, and Kentucky, some areas were more than 6 degrees F (3 C) above normal. Much of the unseasonably warm temperatures were persistent throughout the month. However, there were some cooler spells with below-normal temperatures in some locations during the the month. The preliminary statewide average temperatures in Kentucky and Ohio were the 2nd warmest on record (1895 to 2017) and Indiana was 4th warmest. Many cities in both Ohio and Kentucky including Akron (records began in 1887), Cleveland (1871), and Columbus (1878), Louisville (1872), and Lexington (1872) experienced their warmest April on record. The previous record in each of Columbus, Louisville, and Lexington was from April 1896, more than 120 years ago.
- The heavy rainfall in late April caused major flooding along many rivers and streams in the southern Midwest. In Missouri, four deaths were reported in cars swept off the road at low water crossings and over 100 rescues and evacuations were needed across the state. Interstate 44 in southern Missouri was closed for miles to repair areas where the roadway had been washed away.
- The entire Midwest was free of any abnormally dry conditions at the end of April, per the May 2nd U.S. Drought Monitor. The last time this happened in the Midwest was 15 years ago, in May 2002. The removal of abnormally dry and drought conditions was an improvement from the beginning of April. The March 28th U.S. Drought Monitor showed just over 10 percent of the region in drought and another 10 percent as abnormally dry, mostly in the southwestern Midwest.
- Corn and soybean planting progressed in April, with some states ahead of the 5-year average. As of April 30, Missouri, Illinois, Indiana, and Ohio were ahead of the 5-year average for planting corn and the same states were also ahead for planting soybeans with the exception of Missouri, which was right at the 5-year average. Minnesota was the most behind the 5-year average, with only 12 percent of corn planted (24 percent behind the average) and no soybeans planted (6 percent behind the average). Flooding, ponding, and saturated conditions will necessitate replanting some fields.
- Overall, April was a fairly active month in terms of severe weather. There were several hundred severe weather reports throughout the month, including tornado reports on ten days across eight Midwest states, sparing only Minnesota. There were also hundreds of high wind reports and hundreds of large hail reports in April though there were also 12 days with no severe weather reports. Tornadoes in April included an EF-2 tornado that near Goodman, Missouri on the 4th and an EF-2 tornado near New Madrid, Missouri on the 29th. Wind gusts estimated at 90 miles per hour (145 km per hour) were reported in southern Illinois on the 5th. Hail over 2 inches (5 cm) in diameter was reported in Illinois, Indiana, Iowa, Kentucky, Minnesota, and Missouri during the month with two reports of 2.75 inch (7 cm) hail in Iowa on the 15th.
- For further details on the weather and climate events in the Midwest, see the weekly and monthly reports at the Midwest Climate Watch page.
- Southeast Region: (Information provided by the Southeast Regional Climate Center)
- Temperatures were well above average across the Southeast region, with numerous record-breaking extremes observed during April. Mean temperature departures ranged from 5 to as much as 9 degrees F (2.8 to 5.0 degrees C) above average across much of the region north of Florida, where departures were 1 to 5 degrees F (0.6 to 2.8 degrees C) above average. At least 56 long-term (i.e., period of record equaling or exceeding 50 years) stations, with 34 located in North Carolina and Virginia, observed their warmest April mean temperature on record. A much greater number of long-term stations (88) observed average minimum temperatures that were ranked within the top 3 warmest values on record, compared to 33 stations for average maximum temperatures. However, the persistence of unusual daytime warmth was exceptional for many locations during the month. At least 35 long-term stations observed or tied their highest count of April days with a maximum temperature of 80 degrees F (26.7 degrees C), including Birmingham, AL (1896-2017; 24 days), Augusta, GA (1875-2017; 24 days), Charleston, SC (1938-2017; 21 days), Raleigh, NC (1887-2017; 16 days), and Norfolk, VA (1874-2017; 13 days). From the 10th through the 23rd, Savannah, GA (1874-2017) recorded its longest streak of 14 consecutive days during April with a maximum temperature at or above 80 degrees F. Across the Southeast, the warmest weather of the month occurred from the 28th through the 30th, as unseasonably warm, moist air surged northward around a strong Bermuda High off the Atlantic coast. Daily maximum temperatures exceeded 80 degrees F across much of the region, with several locations in every state reaching 90 degrees F (32.2 degrees C) or higher. Thirteen long-term stations, including 8 in Florida, observed or tied their highest daily maximum temperature on record for April. On the 29th and 30th, Tampa, FL (1890-2017) observed its highest and second highest daily maximum temperature on record for April, reaching 96 and 95 degrees F (35.6 and 35.0 degrees C), respectively. Sixty-three long-term stations, with at least 4 in every state, observed or tied their highest daily minimum temperature on record for April, including Melbourne, FL (1938-2017; 78 degrees F, 25.6 degrees C), Brunswick, GA (1895-2017; 76 degrees F, 24.4 degrees C), Norfolk, VA (1874-2017; 76 degrees F), Muscle Shoals, AL (1893-2017; 72 degrees F, 22.2 degrees C), and Greensboro, NC (1903-2017; 72 degrees F). In contrast, the coldest weather of the month occurred on the 8th, as a continental high pressure system ushered in seasonably cold air from the northwest. Daily minimum temperatures fell below 40 degrees F (4.4 degrees C) across much of the region north of Florida, with several locations reaching 32 degrees F (0 degrees C) or lower. Temperatures were near normal across Puerto Rico and the U.S. Virgin Islands during the month.
- Precipitation ranged from well below normal to well above normal across the Southeast region, with several extremes recorded during April. The driest locations were found across portions of southern Georgia as well as central and southern Florida, where monthly precipitation totals were 50 to less than 5 percent of normal. Orlando, FL (1892-2017) and Wauchula, FL (1933-2017) tied their driest April on record, with no measurable precipitation observed during the month. In contrast, the wettest locations were found across much of the Carolinas and southwestern Virginia, as well as portions of northern Georgia, central Alabama, and northern Florida. Monthly precipitation totals ranged from 150 to over 400 percent of normal in these areas. Raleigh, NC (1887-2017) observed its wettest April on record with 8.66 inches (220 mm) of precipitation, while Asheville, NC (1869-2017) observed its second wettest April on record with 7.65 inches (194 mm) of precipitation. On the 4th, Mayo, FL (1950-2017) and Perry, FL (1930-2017) observed their second and fourth wettest day on record for any month, with 13.70 and 8.12 inches (348 and 206 mm) of precipitation, respectively. On the 7th, Mt. Mitchell, NC (1980-2017) observed its fifth greatest 1-day snowfall on record for April, with 13.0 inches (330 mm). From the 22nd through the 25th, a slow-moving low pressure system produced 2 to nearly 10 inches (50.8 to 254 mm) of rainfall across much of the Carolinas, as well as portions of northern Georgia and southern Virginia. Some of the highest reported totals were 9.91 inches (252 mm) at Raleigh 1.5 SW, NC, 9.61 inches (244 mm) at Busted Rock, VA, and 8.80 inches (224 mm) in Andrews, SC. On the 24th and 25th, thirteen long-term stations in the Carolinas observed their wettest April day on record, including 5.75 inches (146 mm) in Clayton, NC (1956-2017) and 3.67 inches (93.2 mm) in Wilmington, NC (1871-2017). Raleigh, NC (1887-2017) observed its highest 1-day, 2-day, and 3-day precipitation totals on record for meteorological spring (i.e., March-May), with 4.51 inches (115 mm) on the 24th, 6.68 inches (170 mm) from the 24th through the 25th, and 7.45 inches (189 mm) from the 23rd through the 25th. During this event, measurable precipitation was observed for 29 consecutive hours at Raleigh-Durham International Airport, which is the second longest streak at this location since hourly records began in July 1948. Widespread flooding occurred across North Carolina and southwestern Virginia, with several water rescues performed in the Raleigh metropolitan area on the 25th. Precipitation totals were 150 to over 400 percent of normal across much of Puerto Rico and the U.S. Virgin Islands during the month. Christiansted Airport on St. Croix, USVI (1951-2017) observed its third wettest April on record with 7.69 inches (195 mm) of precipitation.
- There were 620 severe weather reports across the Southeast during April, which is over 150 percent of the median monthly frequency of 400 reports during 2000-2015. Approximately 70 percent (446 of 620) of the reports were recorded on just three days during the month (3rd, 5th, and 6th), and over 60 percent (387 of 620) of all reports occurred in Alabama and Georgia. There were 17 reports of large hail (i.e., at least 2 inches in diameter or hen egg-sized) across the region during the month. Thirteen of these reports occurred in east-central Alabama on the 5th, including 4-inch (grapefruit-sized) hail in Talladega County and 3-inch (tea cup-sized) hail in Jefferson, Calhoun, and St. Clair Counties. Numerous reports of damaging thunderstorm wind gusts, ranging from 50 to over 100 mph, occurred across the region, resulting in 9 injuries during the month. On the 3rd, straight-line wind gusts estimated up to 80 mph destroyed 20 boats and overturned a dock at the Fort Gordon Recreational Area in Columbia County, GA, causing 2 minor injuries. On the 6th, a thunderstorm downburst with wind gusts estimated up to 80 mph flipped a few campers at Kissimmee Prairie Preserve State Park in Okeechobee County, FL, injuring 3 people. A total of 68 tornadoes (33 EF-0s, 26 EF-1s, 9 EF-2s) were confirmed across the region during the month, which is about 2.5 times greater than the median frequency of 27 tornadoes observed during April. In fact, this is the third greatest April tornado count for the region since modern records began in 1950, trailing the exceptional count of 226 tornadoes during April 2011 and the 84 tornadoes observed during April 2009. Half (34 of 68) of the tornadoes were observed in Georgia, and over 85 percent (59 of 68) of the tornadoes occurred during severe weather outbreaks on the 3rd and the 5th through the 6th. One fatality and 11 injuries were caused by tornadoes during the month. On the 3rd, an EF-1 tornado touched down in Monroe County, GA and damaged 30 homes along its 8.3-mile track. Several trees fell onto cars as the tornado crossed Interstate 75, resulting in 3 injuries. On the 6th, an EF-0 tornado tracked 4.5 miles from Arlington, VA into Washington, D.C., causing 1 injury. The tornado damaged a light tower in the Pentagon parking lot, uprooted several large trees around the Tidal Basin, and damaged a church roof in downtown Washington. From the 5th through the 7th, non-convective wind gusts exceeding 40 mph were observed across portions of every state north of Florida, as a powerful mid-latitude cyclone traversed the region. Some of the highest recorded gusts included 60 mph at Roanoke Regional Airport, VA, 52 mph at Raleigh-Durham International Airport, NC, 48 mph at Huntsville International Airport, AL, 45 mph at Hartsfield-Jackson International Airport in Atlanta, GA, and 45 mph at Columbia Metropolitan Airport, SC. During clear and relatively calm weather on the 8th, a sudden wind gust in Taylors, SC lifted an inflatable bounce house approximately 20 to 30 feet off the ground and into a set of power lines, injuring 5 children who were inside. On the 5th, three people were injured by lightning strikes in Navarre, FL. An 18-year-old boy was injured while sitting on a metal chair inside his home, and the other two people were using a landline phone at a healthcare facility.
- While drought conditions improved across the northern half of the region, drought development and expansion occurred in southern portions of the region during April. The greatest drought improvement occurred in North Carolina and Virginia, as the coverage of moderate-to-severe (D1-D2) drought decreased from 39 and 41 percent on March 28th to 5 and 16 percent on April 25th, respectively. Moderate-to-severe drought declined significantly across northern Alabama and Georgia, with only a small area of extreme (D3) drought remaining in northeastern Georgia. In contrast, drought continued to intensify and expand across much of the Florida Peninsula, with approximately one third of the state classified in severe drought by the end of the month. Moderate-to-severe drought developed across portions of central and southern Georgia, southeastern Alabama, and coastal South Carolina during the latter half of April. Above-normal precipitation replenished streamflows and soil moisture across much of the Carolinas and Virginia, while much-below-normal streamflows and soil moisture persisted in portions of Alabama, Georgia, and Florida. The most active wildfire season since 2011 continued across Florida, prompting the governor to declare a state of emergency on April 11th. Nearly 600 wildfires were observed and over 32,500 acres were burned across the state during the month. The Cowbell Fire burned nearly 22,000 acres of the Big Cypress National Preserve in southern Florida, but the largest wildfire, known as the West Mims Fire, consumed about 100,000 acres of the Okefenokee National Wildlife Refuge in southeastern Georgia and a small area of northeastern Florida. Smoky conditions around the Okefenokee Swamp reduced tourism and caused temporary road closures due to low visibility. During mid-April, strong winds transported smoke from the West Mims Fire northeastward into portions of the Carolinas and Virginia. Pastures improved across portions of the region that received above-normal precipitation, but drier areas reported minimal pasture growth despite the seasonal green-up. Livestock producers in parts of Alabama had to reseed pastures that were severely damaged by the drought, while insufficient grazing conditions required many producers in Florida to obtain water and hay from outside the state. Farmers in drought-stricken areas of Alabama and Georgia struggled to plant their field crops in hard, parched soils. In early April, severe thunderstorms damaged agricultural fields, buildings, and equipment across portions of Alabama, Georgia, South Carolina, and Virginia. Some losses of early planted corn and other fruit and vegetable crops were reported due to flash flooding, hail, and strong winds. Peach trees in central Georgia struggled to bloom and leaf out because of a lack of wintertime chill hours. Vegetable crops in Florida were affected by an unusually high number of white flies, which was attributed to warm and dry weather during April as well as an unseasonably warm winter across the state.
- For more information, please go to the Southeast Regional Climate Center Home Page.
- High Plains Region: (Information provided by the High Plains Regional Climate Center )
- The wet pattern that has been a primary feature since March continued in places like Wyoming, Kansas, and eastern Colorado during April. As a result of the wetness, mountain snowpack continued to increase throughout the month and is expected to peak later than normal in the Missouri River Basin. Continued wet conditions also nearly eliminated drought in Kansas and eastern Colorado and vastly improved topsoil moisture as well. However, storm systems that passed through the High Plains toward the end of the month caused devastating impacts, particularly to agriculture and livestock.
- Heavy rain and snow, sub-freezing temperatures, and high winds accompanied a couple of storm systems that came through in late April. These conditions killed cattle in Colorado and especially put calves at risk. The long-term presence of drought conditions and early emergence put a stressed winter wheat crop at additional risk for damage in western Kansas. Losses are projected to be greatest in southwestern Kansas where the crop was at a critical growth stage and the greatest impacts occurred. Even in areas that did not sustain sub-freezing temperatures, prolonged cold and wet conditions caused diseases to emerge, such as wheat stripe rust and leaf rust. Besides winter wheat, corn that had already been planted was put at risk in north-central and western Kansas where soil temperatures took a dive. While it appears that southwestern Nebraska may have escaped damage to winter wheat from these storms, the heavy snow may have damaged the alfalfa crop. Damage will be assessed in May after temperatures rise and the snow melts.
- An excessive northern Plains snowpack caused flooding in North Dakota during April. Major flooding occurred in Devils Lake, the Pembina River, and the Souris River. Although April was not a particularly wet month in the northern Plains, excess soil moisture from last fall was preventing producers from getting into the fields. Cool and wet conditions in late April slowed planting of sugar beets in North Dakota and corn in North Dakota and South Dakota.
- After a very warm March, April's temperatures were closer to normal throughout the region. Temperatures ranged from about 2.0 degrees F (1.1 degrees C) below normal to 3.0 degrees F (1.7 degrees C) above normal. Areas experiencing the greatest warmth included southwestern Nebraska through western Kansas, as well as eastern Kansas. However, the region did not experience the record-breaking warmth that occurred in February and March.
- The biggest story of the month in regard to temperatures was several potentially damaging freezes throughout the region. While freezes are common in the area during April, the early emergence of plants due to late winter/early spring warmth put them at risk for freeze damage. With the exception of southeastern Kansas, most of the region had a freeze during April.
- Prolonged freezing temperatures occurred in conjunction with the late-April storm system that impacted much of the region. In particular, the swath of snow that fell throughout central Nebraska and western Kansas held maximum temperatures down into the 30s. The following locations experienced their lowest maximum temperatures on record for April 30th: Grand Island, NE (tie); Dodge City, KS; Garden City, KS; and Ulysses 3NE, KS (COOP). In Dodge City, the high temperature was only 37.0 degrees F (2.8 degrees C), which crushed the previous record by 6.0 degrees F (3.3 degrees C), set in 2004 and 1893. Minimum temperatures were also quite low in some places, and areas of western Kansas sustained sub-freezing temperatures for 12-24 consecutive hours, likely causing freeze injury to winter wheat.
- Precipitation varied across the High Plains during April. Wet conditions were present throughout much of Wyoming, Kansas, and southeastern Colorado, as these areas received greater than 200 percent of normal precipitation. Heavy rain and snow that fell during the month led to several top 10 records for wettest April in these locations. Meanwhile, dry conditions prevailed across much of the Dakotas, but the dryness was not record-breaking.
- Two storm systems that brought rain and snow to the region toward the end of the month contributed to much of the wetness experienced by a large part of the region. One system came through on the 25th-26th, bringing snowfall to the Rockies of Wyoming and Colorado, as well as South Dakota. According to the National Weather Service office in Aberdeen, South Dakota, Aberdeen received 1.8 inches (5 cm) of snowfall on the 26th, which was the most snow to fall there that late in the season since April 1994. In fact, a tornado drill was held on the 26th while snow was on the ground in Aberdeen!
- A second, more impactful storm system moved through the region from April 28th-May 1st. This potent system produced heavy precipitation across parts of Colorado, Wyoming, Kansas, Nebraska, and southeastern South Dakota. This same system spawned tornadoes across the South and Midwest and caused deadly flash flooding in Missouri and Arkansas. A band of heavy snow fell across central Nebraska and western Kansas, with some areas receiving as much as one to two feet (30-61 cm), resulting in several locations setting records for top 10 snowiest April. Because this storm system also impacted the region on May 1st, more details on records will be provided in the May climate summary.
- While this system helped eradicate drought conditions across the central and southern Plains, it caused many negative impacts, particularly for agriculture and ranching. According to agronomy specialists at Kansas State University, snow covered approximately 40 percent of the wheat acreage in Kansas. Heavy snow in the western part of the state knocked winter wheat to the ground, causing stems to break. Damage will be assessed in May after the snow melts and the wheat stands back up. Meanwhile, in Baca County, Colorado, hundreds of cattle were lost or killed due to deep snow and blizzard conditions.
- Another wet month allowed snowpack to continue to build in the Rockies of Wyoming and Colorado. Once again, the Wind River Range in Wyoming received precipitation that exceeded 300 percent of normal for the month. Temperatures were near normal in both states during April, which helped keep the snowpack in place. According to the U.S. Army Corps of Engineers, Snow Water Equivalent (SWE) above Fort Peck Dam was 107 percent of average at the end of April, which was a 13 percent increase from the previous month. Snowpack greatly increased between Fort Peck and Garrison Dams, as SWE went from 129 percent of average to 155 percent of average during the month. The Missouri River Basin mountain snowpack normally peaks near April 15, but given the increase in SWE in both reaches, snowpack will peak late this year.
- Major improvements in drought conditions occurred during April, as beneficial precipitation fell across drought-stricken areas in the High Plains. Regionwide, all severe drought (D2) and extreme drought (D3) were removed by the end of the month on the U.S. Drought Monitor map. The area in drought (D1-D4) in the region decreased from 17 percent to 4 percent, and the area experiencing drought or abnormal dryness (D0-D4) decreased to 20 percent.
- The biggest improvements occurred throughout Kansas. Most of the state received at least 150 percent of normal precipitation, while precipitation exceeded 300 percent of normal in western portions of the state. As of the end of March, nearly half the state was in drought, but it was drought-free by the end of April and only 12 percent of the state was experiencing abnormally dry (D0) conditions. Portions of eastern Colorado and western South Dakota experienced relief in drought conditions as well. Reports state that regionwide, April precipitation has helped grasslands recover in drought-stricken areas.
- Despite recent precipitation and improving conditions, the impacts of drought are still being felt across the parts of the region. Drought conditions during the past six months have caused the winter wheat crop to suffer in Colorado and Kansas. Additionally, ranchers in Kansas are still dealing with the impacts from devastating wildfires in March, which included the loss of cattle and miles of fence, and many are culling herds and buying costlier feed.
- For more information, please go to the High Plains Regional Climate Center Home Page.
- Southern Region: (Information provided by the Southern Regional Climate Center)
- April was a warmer than normal month for all states in the southern region. Temperatures generally averaged between 2 to 6 degrees F (1.11 to 3.33 degrees C) above normal in all of the southern region states. The eastern portion of the region, Mississippi and Tennessee, exhibited temperature anomaly clusters of 6 to 10 degrees F (3.33 to 5.55 degrees C) above normal. In contrast, the temperatures were close to normal for central Texas and western Oklahoma. There were a few parts of Texas that reported slightly below normal temperatures.
- The statewide monthly average temperatures were as follows: Arkansas reporting 64.00 degrees F (17.78 degrees C), Louisiana reporting 69.40 degrees F (20.78 degrees C), Mississippi reporting 67.40 degrees F (19.67 degrees C), Oklahoma reporting 61.20 degrees F (16.22 degrees C), Tennessee reporting 63.20 degrees F (17.33 degrees C), and Texas reporting 67.10 degrees F (19.50 degrees C).
- The state-wide temperature rankings for April are as follows: Arkansas (fourteenth warmest), Louisiana (eighteenth warmest), Mississippi (eleventh warmest), Oklahoma (thirty-sixth warmest), Tennessee (second warmest), and Texas (twenty-fourth warmest). All state rankings are based on the period spanning 1895-2017.
- Precipitation values for the month of April varied spatially across the Southern Region. Precipitation totals in parts of Texas, northern Oklahoma, central Louisiana, and northern Arkansas were 300 percent of normal. Each of the six states in the region had areas 150 to 300 percent of normal precipitation. In contrast, conditions were quite dry across southern Louisiana, northern Mississippi, and parts of Texas with stations reporting between 5 to 70 percent of normal. All states had clusters of normal, below normal and above normal levels of precipitation values. Most of Oklahoma and Arkansas reported above normal precipitation values. Whereas three states, Texas, Louisiana, and Mississippi had great contrasts of precipitation reports throughout their states.
- The state-wide precipitation totals for the month are as follows: Arkansas reporting 8.46 inches (214.88 mm), Louisiana reporting 5.40 inches (137.16 mm), Mississippi reporting 5.91 inches (150.11 mm), Oklahoma reporting 6.48 inches (164.59 mm), Tennessee reporting 6.37 inches (161.80 mm), and Texas reporting 2.62 inches (66.55 mm).
- The state precipitation rankings for the month are as follows: Arkansas (ninth wettest), Louisiana (forty-fifth wettest), Mississippi (forty-third wettest), Oklahoma (fourth wettest), Tennessee (seventeenth wettest), and Texas (fortieth wettest). All state rankings are based on the period spanning 1895-2017.
- Over the month of April 2017, drought conditions improved for most parts of the region, such as areas in Oklahoma and Texas. There were no areas that entered drought from March to April. The area of extreme drought in Oklahoma during March has improved to normal conditions in April. Areas of Oklahoma, northeastern Louisiana, western Arkansas, and northwestern Mississippi are still experiencing moderate drought conditions. At this time, there are no areas experiencing extreme or exceptional drought.
- On April 2, 2017, 31 tornadoes touched down in the southern part of the region including Eastern Texas, Louisiana, and Southern Mississippi. One tornado caused two deaths in St. Martin, Louisiana when a mobile home was blown off its foundation and destroyed. The tornadoes also caused four injuries in Louisiana. There were over 100 strong wind reports in the region as well, snapping numerous trees and power lines. Hail in Texas caused multiple vehicles to be dented and killed chickens.
- On April 4, 2017, there were over 60 reports of hail over three states, Texas, Oklahoma, and Arkansas. There were around a dozen severe wind reports in Northern Oklahoma and Arkansas causing many trees to snap and lay over roads.
- On April 5, 2017, there were two tornadoes reported in Tennessee, one of the tornadoes in Warren, Tennessee caused an injury when a mobile home was destroyed. Trees were also uprooted with barns and outbuildings being damaged and some headstones at the local cemetery were overturned. There were also a dozen hail reports in Tennessee, with half-dollar sized hail reported in Lincoln, Tennessee.
- On April 10, 2017, there were two tornadoes reported in Texas. Over 30 hail events occurred in Texas, with tennis ball sized hail reported in McLennan, Texas. In Crockett, Texas there were 12 lambs killed from the hail.
- On April 11, 2017, tennis ball sized hail fell in Webb, Texas breaking large tree limbs. Eight other hail events occurred in Texas as well with reports of ping-pong ball sized hail in Johnson, Texas.
- On April 12, 2017, golf ball sized hail completely covered the ground and caused damage to multiple vehicles in Hudspeth, Texas. In Reeves, Texas the hail was two feet (0.61 m) deep in some areas of the county.
- On April 14, 2017, there were seven tornadoes in northern Texas that downed power lines. A severe hail event knocked out the windshield of a police car in Parmer, Texas.
- On April 16, 2017, three tornadoes occurred in western Oklahoma. Over 60 hail events were reported in Texas and Oklahoma with a report of Easter egg sized hail in Terry, Texas. The hail caused damage to cars and campers in Briscoe, Texas.
- On April 21, 2017, there were 54 hail reports and 25 wind reports in the region. There were reports of tennis ball and baseball sized hail in Texas including Gainesville, Prosper and McKinney.
- On April 25, 2017, there were a total of five tornado reports in Oklahoma and Arkansas. In Rentiesville, Oklahoma there were reports of baseball sized hail and in Cedar Hill, Texas there were reports of egg sized hail.
- On April 29, 2017, there were ten tornadoes reported throughout the region. There were over 40 hail reports and 100 strong wind events reported.
- On April 30, 2017, there were 15 tornadoes reported in Mississippi and Louisiana. There were over 70 wind reports in Louisiana, Mississippi, and Tennessee. There was one death in Fayetteville, Tennessee when wind causes a tree to fall on a person.
- For more information, please go to the Southern Regional Climate Center Home Page.
- Western Region: (Information provided by the Western Region Climate Center)
- Temperatures were near normal across most of the West this month, with some areas of above normal temperatures along the far southern boundary of the region. Precipitation was variable across the West, though with generally wetter than normal conditions across the northern half of the region and drier than normal conditions across southern portions of California, Nevada, and Arizona.
- The first half of April saw a continuation of the very active storm track that has persisted throughout the cool season. Portions of northern California, notably along the I-80 corridor and in the Sierra Nevada, experienced over 200% of normal precipitation. Sacramento received 3.36 in (85 mm) precipitation, 258% of normal. In the Feather River basin, Portola observed 5.76 in (146 mm), 420% of normal and the second wettest April since records began in 1915. At some higher elevation Sierra Nevada stations, April snowfall was sufficient to eclipse previous snowpack records. At 8801 ft (2683 m), the Mt. Rose Ski area SNOTEL recorded its largest highest snow water equivalent value on record at 94 in (238.8 cm), surpassing the previous record of 87.1 in (221.2 cm) set in May 1995. SNOTEL observations began at Mt Rose in 1979. Areas in and around the Washington Cascades logged over 200% of normal precipitation this month. Wenatchee recorded 2.15 in (55 mm), 467% of normal and the second wettest April since records began in 1959. Above normal precipitation also occurred in areas of western and central Montana, where Great Falls observed 3.58 in (91 mm), 252% of normal, the 3rd wettest April since records began in 1937. Further south, in northeastern New Mexico, Clayton reported 3.33 in (85 mm), 354% of normal and the 10th wettest April in a 122-year record. Above normal rainfall prompted improvements in drought conditions for eastern New Mexico this month. The Sierra Nevada, Cascades, Great Basin ranges, and northern and central Rockies continued to report above normal snowpack values at the end of April, ranging from roughly 125% to over 250% of normal. The southern Rockies reported near normal snowpack with SWE values, roughly 85-110% of normal.
- Drier than normal conditions dominated far southern California, southern Nevada, and much of Arizona this month, not uncommon for the spring season. San Diego, California, recorded only 0.01 in (0.3 m), 1% of normal and tie for 5th driest April since records began in 1939. Both Tucson and Phoenix, Arizona, recorded no measurable precipitation this month, as in many other years in their records. Only 3.8% of the West is currently denoted as having moderate drought conditions or worse; most of this area is in southern California and southwestern Arizona.
- Temperatures were slightly (0-4 F/0-2 C) cooler than normal from the Rocky Mountains westward, with the exception of southern portions of California, Arizona, and New Mexico. These areas reported temperatures +2-4 F (1-2 C) above normal. In Los Angeles, California, temperatures averaged to 67.8 F (19.9 C), 4.7 F (2.6 C) above normal, the 4th warmest April since records began in 1877. Phoenix reported an average temperature of 75.3 F (24.1 C), 2.6 F (1.4 C) above normal and the 8th warmest April in an 85-year record. Areas east of the Rockies were generally within 2 F (1 C) of normal with scattered locations reaching 2-4 F (1-2 C) above normal.
- April was warmer and drier than normal across Alaska. Stations north of the Arctic Circle experienced the greatest temperature departures from normal; Kotzebue reported an average temperature of 24.3 F (-4.3 C), 11 F (6.1 C) above normal. This was the 3rd warmest April since records began in 1897. In the southern part of the state, Anchorage observed an average temperature of 40.4 F (4.7 C), 3.6 F (2 C) above normal and the 4th warmest April in a 66-year record. April is typically a dry month in Alaska, and this year was no exception. Anchorage received 0.4 in (10 mm), which was 85% of normal. Kodiak was the only long-record station with above normal precipitation at 7.35 in (187 mm), 127% of normal. The breakup of ice on various Alaska rivers typically occurs in April, and this year's breakups were within a few days of normal. Further south, above normal temperatures were observed at most reporting stations across the state of Hawaii; departures from normal were typically 1-2 F (0.5-1 C). Hilo recorded an average April temperature of 74.2 F (23.4 C), 2 F (1 C) above normal and the 6th warmest since records began in 1949. Precipitation was variable across the state, though most stations on Oahu and several on Maui reported above normal rainfall. Kahului recorded 7.77 in (197 mm), 501% of normal and the 4th wettest April in a 113-year record. Much of Big Island observed drier than normal conditions; 5.08 in (129 mm) of rain fell at Hilo, 44% of normal. The leeward side of the Big Island saw a small area of drought improvement, while abnormally dry conditions were introduced across the rest of the islands. Central Maui and western Molokai were classified as moderate drought this month.
- April 6-8: Strong late season storm impacted West Coast: High winds (60+ mph/97 kph) downed trees and power lines in northern California and western Oregon, causing temporary power outages for thousands of households. One death was reported in Oregon due to a falling tree. Heavy rainfall associated with this storm initiated a landslide near Oakland, California, destroying three homes. Snowfall of 12+ in (30 cm) was observed in the Sierra Nevada.
- April (all month) landslides cause/threaten damage in West: Saturated soils due to the above average wet winter have primed western soils for landslides. A series of large landslides caused closure of Highway 101 in Mendocino County, California. In Washington, geologists are tracking a slow-moving landslide near Oso. This event prompted temporary closure of a state highway and officials have recommended evacuation for several homes.
- For more information, please go to the Western Regional Climate Center Home Page.
Citing This Report
NOAA National Centers for Environmental Information, State of the Climate: National Climate Report for April 2017, published online May 2017, retrieved on June 5, 2020 from https://www.ncdc.noaa.gov/sotc/national/201704.