National Overview - April 2010
NCDC added Alaska climate divisions to its nClimDiv dataset on Friday, March 6, 2015, coincident with the release of the February 2015 monthly monitoring report. For more information on this data, please visit the Alaska Climate Divisions FAQ.
Maps and Graphics
Temperature and Precipitation Ranks
U.S. Percentage Areas
Did You Know?
In order to place each month and season into historical context, NCDC assigns ranks for each geographic area (division, state, region, etc.) based on how the temperature or precipitation value compares with other values throughout the entire record when sorted from highest to lowest value. In other words, the numeric rank value within the area represents the position or location of the sorted value throughout the historical record (1895-present). As a year is added to the inventory, the length of record increases. As of 2015, NCDC has 121 years of records. Thus a rank of 121 would represent the warmest or wettest on record; a rank of 1 would represent the coolest or driest on record. If a state has a rank of 109, then it would be the 13ᵗʰ warmest or wettest on record. If a state rank has a value of 13, then that state ranked 13ᵗʰ out of 121 years, or 13ᵗʰ coolest or driest.
The "Below Normal", "Near Normal", and "Above Normal" shadings on the color maps represent the bottom, middle, and upper tercile (or three equal portions) of the distribution, respectively. The lowest and uppermost decile (or 10%) of the distribution are marked as "Much Below Normal" and "Much Above Normal", respectively. In other words, for a 121-year period (1895-2015), a rank of Much Above/Below Normal, would be in the top/bottom 12 on record. Below/Above Normal, would represent one of the 40 coolest/warmest or driest/wettest such periods on record. "Near Normal" would represent an average temperature or precipitation value that was not one of the 40 coolest/warmest or driest/wettest on record. For a 121-year period of record, "Near Normal" would represent a rank between 41 and 81.
- Temperature Highlights - April
- For the month of April the temperature, averaged across the contiguous U.S. was above normal. The generally warm and dry influence of persistent high-pressure areas brought above-normal temperatures to most states east of the Rocky Mountains. Only three states (California, Nevada, and Oregon) had cooler-than-average temperatures.
- Regionally, both the Northeast and East North Central climate regions experienced their second warmest April on record. The Central climate region was also above-normal with its fourth warmest such period.
- Record warmth prevailed throughout the Northeast as Maine, Connecticut, Rhode Island, and New Jersey each had their warmest April on record. Illinois also had its warmest such period. In total, 31 states had above-normal temperatures.
- The anomalously warm temperatures in the Northeast can be traced back to the three-month period (February–April) as Maine, Vermont, New Hampshire, Massachusetts, Connecticut, and Rhode Island all experienced record warmth.
- The cooler-than-normal temperatures that prevailed during the latter part of the winter season in the south and southeast were still evident in the three-month (February–April) period. Florida had its coolest such period, while Louisiana and Alabama had their sixth coolest, Georgia its seventh coolest, and both Mississippi and Texas their eighth coolest February–April.
- Maine, Vermont, and New Hampshire, each had their warmest year-to-date (January-April) period on record. Conversely, Florida had its coolest, while South Carolina, Georgia, Alabama, Mississippi, Louisiana, and Texas had average temperatures ranked among their ten coolest.
- Precipitation Highlights - April
- April precipitation in most areas east of the Mississippi River was below average. Wetness returned to the West Coast, as the Northwest climate region averaged much-above-normal precipitation.
- Many Mid-Atlantic states observed much-below-normal precipitation. Both Louisiana and South Carolina experienced their sixth driest April. It was also abnormally dry in Connecticut (8th), North Carolina (9th), Virginia (9th), and Maryland (10th). Conversely, it was Oregon's tenth wettest April on record.
- The dryness in Michigan has persisted throughout 2010, becoming the second driest January-April period on record. The year-to-date period was also the seventh driest for Wisconsin and Kentucky and the eighth driest for Louisiana.
- Other Items of Note
- According to the Rutgers Snow Lab, North American snow cover for April 2010 was the smallest on record (since 1966). Moreover, the anomaly was the largest of any of the 520 months on record.
- NCDC's Climate Extremes Index (CEI) for January-April was about 6 percent higher than the historical average. The CEI measures the occurrence of several types of climate extremes (like record or near-record warmth, dry spells, or rainy periods). Factors contributing to the year-to-date value: a very large footprint (three times larger than average) of extreme wetness and twice the average area with warm minimum temperatures.
- According to NOAA's Storm Prediction Center, 195 tornadoes were reported in April. If the preliminary tornado count stands, it would be the eighth-most number of April tornadoes. Four of the top ten Aprils have occurred since 2000.
- A deadly tornado rated EF-4 on the Enhanced Fujita scale devastated areas near Yazoo City, Mississippi. According to a preliminary analysis by the National Weather Service, the tornado's path was 149 miles long and stretched from extreme northeastern Louisiana to northeastern Misssissippi. The damage path was up to 1 3/4 miles wide at points. The tornado claimed the lives of 10 people.
- Drought coverage increased slightly during the month to a value near historical norms. The U.S. Drought Monitor reported that 9.0 percent of the United States was affected by drought on April 27th.
- Based on NOAA's Residential Energy Demand Temperature Index (REDTI), the contiguous U.S. temperature-related energy demand was 12.1 percent below average for April. which is the 2nd lowest April value in 116 years.
Alaska Temperature and Precipitation:
Beginning with January 2010 processing, the Alaska temperature and precipitation report is comprised of several datasets at NCDC, integrating GHCN and COOP datasets. Prior to 2010, the Alaskan temperature timeseries was processed with just GHCN data.
had its 33rd warmest April since records began in 1918, with a
temperature 1.4°F (0.8°C) above the 1971–2000
had its 29th warmest February–April on record, with a
temperature 1.3°F (0.7°C) above the 1971–2000
- Alaska had its 35th warmest year–to–date on record, with a temperature 0.9°F (0.5°C) above the 1971–2000 average.
had its 27th wettest April since records began in 1918, with
an anomaly that was 22 percent above the 1971–2000
had its 42nd driest February–April on record, with
an anomaly that was 4 percent above the 1971–2000
had its 24th driest year–to–date on record, with
an anomaly that was 9 percent below the 1971–2000
For additional details about recent temperatures and precipitation across the U.S., see the Regional Highlights section below. For information on local temperature and precipitation records during the month, please visit NCDC's Records page. For details and graphics on weather events across the U.S. and the globe please visit NCDC's Global Hazards page.
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 Climatic Data Center.
- Northeast Region: (Information provided by the Northeast Regional Climate Center)
- Not only was April 2010 the 2nd consecutive month with above normal temperatures, but it was also the 2nd month in a row that the average temperature was ranked among the top ten warmest since 1895. The average for March was the 6th warmest, while April was the 2nd warmest in 116 years. The monthly average of 50.7 degrees F (10.4 degrees C) was 5.2 degrees F (2.9 degrees C) above normal. Daily maximum temperature records were set throughout the Northeast every day from the 1st to the 8th. Of the 35 First Order stations in the Northeast, 12 saw their warmest April on record and 7 had their 2nd warmest. It was the warmest April since 1895 in Connecticut, Maine, New Jersey, and Rhode Island and the 2nd warmest in Delaware, Massachusetts, New Hampshire and New York. Pennsylvania saw its 4th warmest and the average temperatures in Maryland, Vermont and West Virginia placed those states at 5th warmest. Departures ranged from 3.8 degrees F (2.1 degrees C) above normal in Maryland to 6.1 degrees F (3.4 degrees C) above normal in Maine.
- The weather pattern that kept the Northeast warm in April also kept it dry. The region's precipitation total was 2.19 inches (55.6mm), which was 61 percent of normal. It was the Northeast's 13th driest April since recordkeeping began in 1895, the 8th driest in Connecticut and the 10th driest in Maryland and Massachusetts. Of the thirteen states in the region, twelve had precipitation totals that were below normal and one, Vermont, had a total that was exactly normal. Departures among the dry states ranged from 36 percent of normal in Connecticut, to 78 percent of normal in Maine. Two months of below normal precipitation in western portions of the region have led to drought concerns as the growing season begins. According to the U.S. Drought Monitor of April 27, 2010, the region had two areas in moderate drought - the New York counties at the east end of Lake Ontario and northwest Pennsylvania. A larger area, stretching from northern New York to western Pennsylvania and into northern West Virginia, was experiencing abnormally dry conditions.
- For more information, please go to the Northeast Regional Climate Center Home Page.
- Midwest Region: (Information provided by the Midwest Regional Climate Center)
- April temperatures were well above normal ranging from 3 degrees F (2 degrees C) above normal in southeast Kentucky to as much as 9 degrees F (5 degrees C) above normal in northern Minnesota and Wisconsin. The beginning of the month was particularly warm, then as the month went on, temperatures eased closer to normal. Several long-term stations recorded their warmest April including Peoria, Illinois (records began in 1883), Springfield, Illinois (1879), Moline, Illinois (1872), Burlington, Iowa (1897), Duluth, Minnesota (1871), and Marquette, Michigan (1948). Many other Midwest stations neared their records. Statewide April temperatures ranked all nine Midwest states among the warmest seven since 1895 based on preliminary data. Illinois set a new record, Indiana and Wisconsin ranked second, Minnesota third, Michigan and Ohio fourth, Iowa fifth, and both Kentucky and Missouri ranked seventh. Hundreds of daily records were set in April, mostly record highs. There were 796 record high maximums and 567 record high minimums. Only 21 record low minimums and 9 record low maximums occurred during the month. The first three days of April accounted for nearly 700 daily records.
- April precipitation was below normal for most of the Midwest. From southern Missouri to Michigan and areas to the southeast totals were generally below normal with southeast Ohio receiving less than 50 percent of normal. Another swath of below normal precipitation extended form northwest Iowa, across most of Minnesota, northern Wisconsin, and the Upper Peninsula of Michigan. Near Lake Superior totals were less than 50 percent of normal with the northeast tip of Minnesota getting less than 25 percent of normal. Above normal rains fell in northern Missouri, southwest Iowa, northwest Illinois, southern Wisconsin, and the Red River Valley in northwest Minnesota. The heaviest rains fell in northeast Missouri where 5 to 7 inches (125 to 175 mm) put the monthly totals above 150 percent of normal.
- Minnesota recorded its first April with no measurable snow since at least 1891 when modern records began. Duluth reported just a trace of snow on the 7th of April. The snowless April followed a nearly snowless March when just a couple stations reported measureable snow on one or two days. Duluth, Minnesota reported no measureable snow in March or April with just a trace on one day each month. Corn planting proceeded on a record pace with 50 percent of the nationwide crop planted by April 25th. The previous high was 37 percent since 1974 when records began. Midwest states were also at record paces with planting going very quickly especially in the latter half of April. As of April 25th, Kentucky had 74 percent of its corn planted, Illinois 73 percent, Missouri 69 percent, Iowa 68 percent, Minnesota 63 percent, Indiana 56 percent, Ohio 45 percent, Michigan 32 percent, and Wisconsin 20 percent. Wisconsin was 13 percent ahead of the past 5-year average, Kentucky, Ohio, Michigan, and Missouri were 20 percent to 40 percent ahead of the average, and Iowa, Illinois, Indiana, and Minnesota were more than 40 percent ahead of the average.
- For details on the weather and climate events of the Midwest, see the weekly summaries in the MRCC Midwest Climate Watch page.
- Southeast Region: (Information provided by the Southeast Regional Climate Center)
- For the first time in over three months, mean temperatures for April 2010 were above normal over a large portion of the Southeast. However, there was much variability throughout the month, with the coldest temperatures occurring at the beginning and end of the month and the warmest temperatures occurring in the middle of the month. Mean temperatures across the state of Virginia were more than 5 degrees F (2.8 degrees C) above normal, while most of Florida was only slightly above normal. It was the third warmest April at Roanoke, Virginia?s Regional Airport for a record extending back to 1912. Across the region, 501 record daily maximum temperatures were tied or broken during the month, and more than half occurred in Virginia and North Carolina. Washington Dulles Airport tied a monthly record high of 93 degrees F (33.9 degrees C) on the 6th of the month, and then tied it again on the 17th, for a record extending back to 1962. San Juan, Puerto Rico registered a daily record high of 94 degrees F (34.4 degrees C) on the 28th of the month. Minimum temperatures were also unusually high across parts of the Southeast; 143 record high minimum temperatures were tied or broken during the month, and the majority of these occurred in Virginia. In particular, April 6th and 7th marked the earliest dates in the calendar year that the Naval Air Station at Norfolk, VA recorded a minimum temperature above 70 degrees F (21.1 degrees C). For the third consecutive month, mean monthly temperatures were above normal across Puerto Rico. While early spring warmth dominated much of the region, portions of Florida continued a multi-month streak of below normal temperatures. Jacksonville, Florida showed the coldest start to a calendar year in a record extending back to 1871.
- Continuing the trend from March, precipitation totals for April 2010 were below normal across most of the region. In general, precipitation totals were between 50 and 75 percent of normal across Virginia, North and South Carolina, and much of Georgia and Alabama. Precipitation was close to normal across Puerto Rico. In contrast, monthly precipitation across the southern half of Florida was between 200 to more than 300 percent of normal. Fort Lauderdale, Florida received 12.53 inches (318 mm) of precipitation for the month, making it the third wettest April in a record extending back to 1912. Additionally, narrow swaths of above-normal precipitation (100-150 percent) were recorded in Georgia and Alabama. Much of this precipitation was connected with a series of strong thunderstorms that tracked across the region on the 25th of the month. Berry, Alabama recorded a record monthly 24-hr rainfall of 5.35 inches (136 mm), which broke the old record by over two inches. In other parts of the Southeast, monthly precipitation totals were well below normal (5-25 percent). These areas included southwest Alabama, northeast Florida, and much of the coastal Carolinas. Federal Point, Florida, located near St. Augustine, recorded only 0.20 inches (5.08 mm) of precipitation, which was 9 percent of normal for the month. Charleston International Airport in South Carolina experienced the 5th driest April in a record extending to 1938, with only 0.70 inches (17.78 mm) of precipitation. It was the driest April in New Bern and Lumberton, North Carolina, according to records extending back to 1948 at both stations.
- There were 248 reports of severe weather across the Southeast during the month, including 31 tornadoes. Most of these tornadoes were associated with a major severe weather outbreak that occurred on the 24th and 25th of the month. A number of tornado reports in Alabama during this outbreak were connected with a single tornado that covered nearly 150 miles from western Mississippi to northeast Alabama. Another series of severe thunderstorms connected with this outbreak produced strong (EF-2) tornadoes, including an EF-4, in northern Alabama. Some weaker tornadoes were reported in Georgia and eastern North and South Carolina during this outbreak, including one near Darlington, South Carolina that resulted in three injuries.
- Drought conditions returned to the Southeast region in April, which had been drought-free since January. A small area of abnormal dryness (D0) developed in southern Alabama and extreme western Florida early in the month. By the end of the month, abnormally dry conditions had developed in northern Alabama as well as through central and eastern regions of the Carolinas where precipitation deficits were the greatest.
- 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)
- April 2010 was warmer than normal for most locations across the High Plains Region. The highest above normal temperature departures occurred in the eastern Dakotas where temperature departures were 6-10 degrees F (3.3-5.6 degrees C) above normal. The above normal temperature departures tapered off in intensity toward the western part of the Region, ending in central Wyoming and northern Colorado, where temperature departures of 2-4 degrees F (1.1-2.2 degrees C) below normal occurred. Many locations across eastern portions of North Dakota and South Dakota were ranked in the top 10 warmest Aprils on record and at least two locations set or tied for the warmest on record. Fargo, North Dakota recorded its warmest April on record (period of record 1881-2010) with an average temperature of 51.6 degrees F (10.9 degrees C) which was 8.1 degrees F (4.5 degrees C) above normal. This beat the old record of 51.5 degrees F (10.8 degrees C) which occurred in both 1915 and 1987. Britton, South Dakota tied its own 1987 record for the warmest April (period of record 1893-2010) with an average temperature of 53.5 degrees F (11.9 degrees C).
- Precipitation varied this month and areas of the Region which received at least 150 percent of normal precipitation included north and central North Dakota, southwestern South Dakota, western Nebraska, northern Kansas, western and southeastern Wyoming, and northern Colorado. While western Wyoming received above normal precipitation this month, it was not enough to make a dent in the ongoing drought conditions. Meanwhile, an ongoing lack of precipitation in northwestern North Dakota and south central Kansas led to the development of abnormally dry conditions. April was an active month as weather ranging from snow to tornadoes affected parts of the Region. Early in the month, a series of snowstorms hit Wyoming pushing snow totals for the season even higher. For example, Riverton, Wyoming, with 61.9 inches (157.2 cm) of snow, now ranks as the second snowiest season on record (period of record 1907-2010). Later in the month, severe storms affected areas of the Region. In particular, April 22nd was one of the most active severe weather days of the month for the High Plains Region. Numerous tornadoes, large hail, and damaging thunderstorm winds were reported in eastern Colorado and western Kansas. These storms also produced heavy rain which caused record precipitation totals. One of these locations was Healy, Kansas. During the 24-hour period from April 22-23, Healy, Kansas received a record 4.26 inches (108.20 mm) of precipitation. According to a local sheriff, up to 4 feet of water covered the streets in the downtown area. This precipitation not only set the new record for the day, but also for the highest one day precipitation total for the month of April and the 4th highest one day precipitation total for the entire period of record (period of record 1901-2010). In addition, for the month of April, Healy, Kansas received 5.82 inches (147.83 mm) of precipitation, or 305 percent of normal. This beat the old record of 5.77 inches (146.56 mm) received in April 1984.
- Minor changes to the drought monitor occurred this month. Abnormally dry conditions (D0) developed in central Kansas and also spread from Montana east into the northwest corner of North Dakota. Both areas have experienced below normal precipitation over the past few months. The drought conditions in Colorado and Wyoming have remained largely unchanged from last month. According to the U.S. Seasonal Drought Outlook released April 15th, the moderate drought conditions (D2) in northwestern Colorado and southwestern Wyoming are expected to improve through July 2010, however the moderate (D1) to severe drought conditions (D2) in the remaining areas of Wyoming are expected to persist.
- For more information, please go to the High Plains Regional Climate Center Home Page.
- Southern Region: (Information provided by the Southern Regional Climate Center)
- In opposition to last month and much of the past winter, April mean monthly temperature averages in the Southern Region were generally near to slightly above normal. The only exception to this was in the southern half of Texas, were most stations reported temperature values that fell in the range of 0 to 2 degrees F (0 to 1.11 degrees C) below the monthly normal. In northern Texas, most stations reported values that were only 0 to 2 degrees F (0 to 1.11 degrees C) above normal. Similar values were also observed in southern Oklahoma, much of southern Mississippi and most of Louisiana; with the exception of the northeast. Elsewhere in the region, temperature averages ranged from 2 to 4 degree F (1.11 to 2.22 degrees C) above normal. Temperature anomalies were highest in the state of Tennessee and in northeastern Arkansas. There, temperature averages ranged from 4 to 8 degrees F (2.22 to 4.44 degrees C) above normal. Tennessee reported a state-wide average temperature of 61.10 degrees F (16.67 degrees C), making it the 13th warmest April on record (1985-2010).
- Monthly precipitation totals for the month of April were quite variable over the Southern Region. The highest negative precipitation anomalies were observed in central and southern Louisiana, where most stations reported less than one quarter of the monthly normal. Similar values were also observed in southwestern Mississippi and southeastern Texas. The state of Louisiana reported a state-wide average precipitation value of 1.23 inches (31.24 mm), which was the sixth driest April on record (1895-2010). Mississippi reported a state-wide average precipitation of 2.71 inches (68.83 mm), which was the 15th driest April on record (1895-2010) In contrast, conditions were quite wet in the western half of Texas, with many stations reporting more than 200 percent of normal precipitation. Elsewhere in the region, most stations reported slightly below normal precipitation for the month. Precipitation values generally ranged from 50 to 75 percent of normal.
- After nine consecutive weeks of being completely drought-free, the Southern Region is now showing a small area of moderate (D1) drought in northeastern Louisiana. The drought level was declared on the April 20, 2010 United States Drought Monitor Map, and it has persisted through to the end of the month. The area of D1 drought makes up 1.3 percent of area of the Southern Region and 11.92 percent of the area of Louisiana.
- On April 1 and April 2, several wind reports were filed for areas that covered much of central and northeastern Oklahoma. There were numerous reports of damage to homes, with several sheds blown over, barns destroyed, tree limbs snapped and power lines downed. In Creek County, Oklahoma, wind speeds were reported to be in the range of 70-80 miles per hour (113-129 km/hr).
- On April 7, 60 mile per hour (97 km/hr) wind gusts were reported in Greene County, Arkansas. Several tree limbs were snapped and two mobile homes were destroyed. In Craighead County Arkansas, a flat bottom boat was reported to have been flipped, tosses and impaled up on a second story I-beam support structure.
- On April 20, two tornadoes were reported in the vicinity of the Texas panhandle. One occurred in Potter County and the other occurred in Randall County. For both storms, no injuries or fatalities were reported and there was no mention of any significant damage to structures in the area.
- On April 23-24, a strong cold front pushed across the Southern Region. As the front pushed through, it collided with warm, moist maritime tropical air. This resulted in a series of devastating storms. Several dozens of tornadoes were reported in an area covering northeast Texas, central and southern Arkansas, northeastern Louisiana, most of Mississippi and Tennessee. The hardest hit state was Mississippi. In Pontotoc County, Mississippi, 10 fatalities were reported from a twister that was observed to be 1.75 miles (2.82 km) wide (at its maximum width). The storm had an approximate path length of 149 miles (239.79 km), making it one of the most devastating tornadoes to hit the state in the history of keeping records. In addition to the 10 fatalities, 75 injuries were reported. Tornadoes touched down or passed through many other counties, including Holmes County where numerous homes sustained structural damages. One fatality and one injury was reported in Holmes County. In Yazoo City, approximately 30 homes were destroyed from the storms, and thousands of people were left without electricity. In Choctaw County, Mississippi, three tornado-related fatalities were reported. A tornado in Monroe County, Mississippi left one person injured. In addition to the twisters, there were dozens of hail and damaging wind reports. In Chester County, Mississippi, softball-sized hail was reported, while in Lowndes County, Mississippi, hail was reported to be about the size of tennis balls.
- On April 30, several tornadoes were reported in Arkansas. Reports indicated that several homes were damaged in Stone County, although a bulk of the damage was limited to tree limbs and power lines. Fortunately, there was no mention of any fatalities or injuries as a result of the storms.
- For more information, please go to the Southern Regional Climate Center Home Page.
- Western Region: (Information provided by the Western Regional Climate Center)
- Although April in the West was generally cool and wet, no record-setting events occurred. Temperatures were generally on the cool side throughout the West, with central California 4-5 deg F (2-3 deg C) below normal. Locations east of the Rockies and in the southern Intermountain region were a bit above normal.
- Precipitation was well above normal in most of California and below normal in the Southwest. The Northwest and Intermountain regions had scattered regions of above and below normal precipitation.
- Mountain snowpack on May 1st was mostly below normal except for the Sierra Nevada of California and higher elevations of the Southwest. Snowpack in the Central Sierra rose from 90% of normal on April 1st to just over 120% of normal by May 1st (barely losing any snow water equivalent) thanks to cool and wet conditions in April that prevented much melting.
- April 27-30: Late Season Winter Storm: A powerful late season winter storm hit California and Nevada with strong winds, heavy rain and heavy mountain snow from the 27th to the 29th. Winds gusted to over 90 mph in western Nevada and eastern California valleys causing numerous trucks to overturn on U.S. 395. Winds in the Reno area hit 95 mph causing significant local damage, power outages to over 5000 customers, and the diversion, cancellation or delay of 16 flights at Reno Airport. Winds in the Sierra crested at 130 mph with heavy snow. Donner Summit measured 25 inches (63.5 cm) of snow throughout the event. Some locations in northwest California received over 6 inches (152 mm) of rain, very unusual for so late in the season. In Montana, up to 4 feet of snow fell in the Mission Mountains and Little Belt Range on the 29th and 30th. Numerous power outages occurred across that state with the combination of heavy snow and strong winds of up to 60 mph. At several locations, new record low barometric pressures for April were recorded.
See NCDC's Monthly Records web-page for weather and climate records for the month of May. For additional national, regional, and statewide data and graphics from 1895-present, for any period, please visit the Climate at a Glance page.
PLEASE NOTE: All of the temperature and precipitation ranks and values are based on preliminary data. The ranks will change when the final data are processed, but will not be replaced on these pages. Graphics based on final data are provided on the Climate Monitoring Products page and the Climate at a Glance page as they become available.