April 2009 National Climate Report

• For the contiguous United States, the average temperature for April was 51.2°F (10.7°C), which was 0.8°F (0.5°C) below the 20th century mean and ranked as the 36th coolest April on record, based on preliminary data.

• On the regional level, much of the U.S. experienced near normal temperatures during April. The West North Central region had below average temperatures and the Northeast experienced above average temperatures.

• Using the Residential Energy Demand Temperature Index (REDTI - an index developed at NOAA to relate energy usage to climate), the nation's residential energy demand during April was approximately 2.3% below average consumption and ranked as the 44th lowest in 115 years.

• This was the 35th wettest April in the 1895—2009 record. An average of 2.62 inches (66.6 mm) of precipitation fell across the contiguous U.S. this month, which is 0.19 inch (4.7 mm) above average.

• April was wetter than normal for the South and Central regions of the U.S. and drier than normal for the West and Northwest regions.

• It is reported by the Climate Prediction Center (CPC) that La Niña conditions were transitioning to ENSO-neutral in the equatorial Pacific Ocean. Equatorial sea-surface temperatures have continued to weaken and the tropical convection and wind patterns reflect weak La Niña conditions. Based on the recent observational trends, the CPC is foreceasting a complete transition to ENSO-neutral conditions. While in an ENSO-neutral state, weather patterns can be variable due to the influence of other teleconnections such as the Madden Julian Oscillation (MJO) and the North Atlantic Oscillation (NAO), thus are not easily predicted in larger time scales. For additional information on ENSO conditions, please visit the NCDC ENSO Monitoring page and the latest NOAA ENSO Advisory.

• Alaska had its 36th warmest April since records began in 1918, with a temperature 0.4°F (0.2°C) above the 1971—2000 average.
  
  
• Alaska had its 51st coolest February—April on record, with a temperature 0.2°F (0.1°C) below the 1971—2000 average.
  
  
• Alaska had its 48th coolest January—April on record, with a temperature 0.7°F (0.4°C) below the 1971—2000 average.

For additional details about recent temperatures and precipitation across the U.S., see the Regional Highlights section below and visit the April Climate Summary page. For information on local temperature and precipitation records during the month of April, please visit NCDC's Extremes page. For details and graphics on weather events across the U.S. and the globe please visit NCDC's Global Hazards page.

• April 2009 was the third consecutive month with above normal temperatures in the Northeast. The regional average of 47.5°F (8.6°C) was 2.1°F (1.2°C) above normal. The northern states saw the greatest positive departures, from 2.2°F (1.2°C) above normal in New Jersey to 3.3°F (1.8°C) warmer than normal in New Hampshire, where it was the 8th warmest April since 1895. Maryland was the closest to normal, with temperatures that were only 0.5°F (0.3°C) warmer than the long term mean. An early season heat wave during the last week of the month was a major contributor to the above normal monthly average. Many daily and even monthly all-time high records were set during the event, including the first time the temperature in Portland, ME topped 90°F (32.2°C) in April.
  
  
• For the fourth month in a row, the Northeast averaged below normal precipitation. The regional average was 3.24 inches (82.3 mm) or 91% of the normal April precipitation amount. This represented a range of values from 66% of normal in Vermont to 141% of normal in Delaware. The general weather pattern this month kept the bulk of the precipitation in the southern three states and along the coast, leaving interior sections of the Northeast quite dry.
  
  
• Above normal rainfall in the southern third of the Northeast improved drought conditions in West Virginia and Maryland from moderate to abnormally dry, according to the April 28, 2009 U.S. Drought Monitor. Most of western West Virginia improved to normal conditions. Below normal precipitation in the central portion of the Northeast resulted in abnormally dry conditions in Delaware, New Jersey, Pennsylvania, southern New York and western Massachusetts and Connecticut.
  

• April temperatures were close to normal, -2°F to 2°F (-1.1°C to 1.1°C), across most of the region. Along the western edge of the region temperatures were slightly cooler with a minimum of about 4°F (2.2°C) along the Iowa-Missouri border. While the average temperature was near normal, the weekly temperatures were not, especially in the southern two-thirds of the region. The first 20 days of the month were below average across the southern two-thirds with Missouri averaging about 5°F (2.8°C) below normal. Many record lows, particularly record low maximum temperatures, were set during this time. The last ten days of the month were dominated by strong southerly winds bringing warm advection and preventing nighttime inversions. Many record high maximum temperatures were set and hundreds of record high minimum temperatures were set, with most occurring on April 25 to 27.
  
  
• April was a wet month with nearly all the region receiving above normal precipitation. Minnesota, northwest Iowa, northwest Wisconsin, and eastern Ohio were below normal for the month, but elsewhere precipitation was above normal. A swath of much above normal precipitation (greater than 150%) extended from northern Missouri through Illinois and into central Indiana. Peak values reached over 200% of normal in southeastern Illinois where two stations reported over 9 inches (225 mm) of rain. Record April totals included Hutsonville Power Plant (9.48 inches, 241 mm) and Palestine (9.89 inches 251 mm), both in Crawford County, Illinois as well as Butler (9.10 inches, 231 mm) in west central Missouri.
  
  
• Red River flooding continued for the entire month. A second crest of the river was several feet short of the earlier crest but still well into the major flooding category. The extended period of flooding put a severe strain on the communities along the river in Minnesota and North Dakota but for the most part breeches of the temporary levees was limited. Flooding in other areas improved throughout the month until the last week of April. A widespread rain event associated with a strong cold front brought heavy rains across the region and renewed minor to moderate flooding conditions from Missouri to Michigan.
  
  
• Numerous storms tracked across the region this month. The associated rain brought some areas heavy rain but other areas were spared. While the paths of the storms varied, the upper Midwest continued in drought until finally getting some relief in the last eight days of the month. On the other hand, Illinois continued to get rain from the various storms and farm fields remain too wet to work in most of the state. While most other states have gotten limited days in the field, Illinois corn planting is well behind schedule.
  

• Mean temperatures for April 2009 displayed much variability across the region. Temperatures were slightly below normal across much of AL, GA, SC, portions of northern FL, and small areas of NC. Temperatures were slightly above normal across northern and eastern NC, much of VA, south central FL, and small portions of AL, GA, and SC. In Puerto Rico, temperatures were slightly below normal across much of the island. The coldest temperatures during the month were observed behind a strong cold front that passed through the Southeast on the 6th of the month. Low temperatures of 23°F (-5°C) and 25°F (-4°C) were observed at Blairsville, GA and Jocassee, SC, respectively, on the morning of the 8th. Tallahassee, FL dropped to 31°F (-1°C) on the 9th marking the ninth spell of sub-freezing air over the last four months in the region. This late freeze was 37 days later than the climatological last freeze date for the location. During the last week of the month, exceptionally warm air dominated the region as the Bermuda High extended westward over the region. There were 174 record daily high temperatures across the region, including Bremo Bluffs, VA, which recorded a high temperature of 96°F 36°C) on the 26th. Washington Dulles airport recorded three straight days in which the maximum temperature equaled 92 °F (33°C). This was the earliest seasonal occurrence of a 3-day string of 90°F (32°C) or greater maximum temperatures for a record extending back to 1962.
  
  
• Much of the region displayed below normal precipitation totals for April, especially SC, NC, southern VA and the southern three-quarters of FL. Monthly precipitation totals were less than 50% of normal across much of southern FL. Most notably, Oasis Research Station, FL recorded only 0.27 inches (7 mm) of precipitation for the month. In contrast, monthly precipitation totals across most of GA and small portions of AL and SC were above normal, especially portions of south GA and the western panhandle of FL, where precipitation totals were more than 200% of normal. Fargo, GA and Jasper, FL recorded 12.59 inches (320 mm) and 11.80 inches (300 mm) of precipitation, respectively, for the month, which was about 450 and 350% of the normal monthly totals. Most of Puerto Rico experienced below normal precipitation totals for the month. The prodigious monthly precipitation totals over southern GA and western FL were associated with multiple mesoscale convective systems that tracked across the region in association with the approach of two cold fronts between the 1st and 3rd of the month. Quitman, GA and Jasper, FL recorded 3-day precipitation totals that exceeded 10 inches (254 mm) during this period. Near record flooding occurred along several rivers in southern GA that impacted at least 80 building structures. The exceptionally wet conditions forced many farmers to replant their corn crop.
  
  
• Severe drought (D2) conditions persisted across portions of central and southern FL, and a small region of southwestern FL was upgraded to the extreme drought classification (D3). Drought conditions in northeast GA and northwest SC showed continued improvement early in the month in response to plentiful rainfall in late March and early April. The small area of severe drought (D2) in northwest SC was downgraded to the moderate drought (D1) classification. This was tied to a reduction of the size of the D1 region, which occupied only small portion of northeastern GA and western NC by the middle of the month. Moderate drought conditions across northern VA lessened to abnormally dry conditions during the month. Dry conditions over the last 4 months contributed to the development and rapid spread of a wildfire near Myrtle Beach, SC on the 22nd that burned nearly 20,000 acres and destroyed 76 homes. Additionally on the 23rd of the month, lightning sparked a brush fire in the drought-stricken Everglades of southern FL forcing the closure of Interstate 75. An exceptional number of severe thunderstorms were observed across AL, GA, portions of SC and northern FL during the month. There were 54 and 37 preliminary tornado reports across AL and GA, respectively, which is greater than any of the prior 10 years of reports for the month of April. On the 10th of the month, a severe thunderstorm outbreak produced numerous high wind, hail, and tornado reports, including an EF-3 tornado in Aiken County, SC that caused significant damage to homes and businesses as well as one death. The frequent occurrence of hail and strong winds across GA during the month damaged trees in various peach and pecan orchards. Lightning sparked a number of building fires on the 24th in the metro Atlanta, GA area and caused the evacuation of the control tower at Hartsfield-Jackson airport, resulting in many flight delays.
  

• This April the High Plains Region was cool with common average monthly temperature departures ranging from near normal to 6°F (3.3°C) below normal. While the cool average temperatures were not record breaking for the majority of the region, a few locations ranked in the top 10 coolest Aprils on record. For instance, White Lake, SD recorded its 8th coolest April with an average temperature of 42.5°F (5.8°C). The record coolest April was recorded in 1950 with an average temperature of 39.2°F (4.0°C).
  
  
• Southeast Kansas was the wettest area in the region this month, with many locations receiving several inches above normal precipitation. This month?s extreme locations were Wichita, KS and Anthony, KS which both broke several precipitation records. Wichita recorded its 2nd wettest April on record with 9.94 inches (252.5 mm). Of this monthly total, 5.10 inches (129.5 mm) fell in one day (April 26), which set a daily record as well. Anthony recorded its wettest April with 9.91 inches (251.7 mm), or 341% of normal. The previous wettest April occurred in 1970 with 7.54 inches (191.5 mm). The wettest day to ever occur in April was on April 27, 2009, when Anthony received 6.55 inches (166.4 mm) of rain. This smashed the old record of 2.20 inches (55.9 mm) which was recorded in 1938. In addition, this 24-hour precipitation total was the 3rd greatest 24-hour precipitation total on record for this location (period of record 1896-present).
  
  
• Over the past month showers and thunderstorms helped erase the D2, D1, and much of the D0 conditions in Kansas. However, areas across north central Kansas and eastern Nebraska missed out and D0 conditions have spread. Drought conditions have improved across Wyoming and parts of Colorado, however, abnormally dry conditions (D0) have reemerged in western North Dakota. According to the U.S. Seasonal Drought Outlook released April 16, drought conditions are forecasted to persist in Wyoming, but improve in Colorado through July 2009.
  
  
• According to the North Central River Forecast Center, Devils Lake in North Dakota reached record levels this month. Since fall of last year, Devils Lake has been rising due to heavy precipitation in the area. The lake continued to rise through the winter and the rise is now accelerating due to the spring snow melt. The previous record level of 1449.2 ft asl was surpassed on April 30, 2009 and is forecasted to rise to a level between 1451 ft asl and 1452 ft asl sometime in the late spring or early summer of this year. At a level of 1446 ft asl, Devils Lake spills into nearby Stump Lake causing the two lakes to become a single body of water. According to the North Dakota State Water Commission, the flooding, which began in the 1990's and has continued to the present has destroyed hundreds of homes and businesses and has inundated thousands of acres of productive farmland.
  

• Some small, isolated areas in eastern Texas, eastern Oklahoma, and northern Arkansas reported average monthly temperatures that ranged between 2-4 ° F (1-2 °C) below normal. In general however, average temperatures for April in the Southern Region were within about 2 degrees of normal (1 °C). The highest anomalies were observed in southern Texas; an area that has been fraught with drought for several months.
  
  
• The month of April proved to be one of variable precipitation for the Southern Region. Large areas of the region experienced above normal monthly totals, while other large areas received below normal precipitation. In the case of the latter, precipitation totals in Mississippi were generally below 75 percent of normal. In the coastal areas of the state, monthly totals ranged from 25-50 percent of the monthly allotment. This was also the case for south eastern Louisiana, specifically, the Florida parishes of the state. There was also a second dry belt that extended from north eastern Louisiana, through central Mississippi to north eastern Mississippi. Along this belt, monthly totals ranged from 25 to 50% of normal. The driest areas of the Southern Region consisted of the western Texas panhandle and the southern tip of Texas where precipitation totals were mostly below 25% of normal. Many stations in Texas Climate Divisions 5 (Trans Pecos) and 10 (Lower Valley) reported little to no precipitation for the month. Conversely, the wettest portions of the Southern Region included south eastern Texas, west central Texas, and north central Texas and south central Oklahoma. These areas all experienced precipitation totals that ranged from 200 to 400 percent of normal. Elsewhere in the Southern Region, precipitation totals fell in the 75% to 125% of normal range.
  
  
• The spatially variable pattern of April precipitation led to both improvements and deteriorations in drought conditions within the Southern Region. In eastern Tennessee near normal precipitation led to improved conditions and the state is now drought free. Similarly, normal rainfall for the month in southern Arkansas resulted in the removal of abnormally dry conditions. Heavy precipitation totals in Oklahoma allowed for a great improvement throughout the state. For instance, the southern Oklahoma border, which last month was categorized as moderate to severe drought, is now relatively drought-free. Drought conditions were also improved by one category along the Oklahoma panhandle. Last month, this area was categorized as moderate to severe drought. As of May 5th, 2009, only a small area of the Oklahoma panhandle was exhibiting abnormally dry conditions. In Texas, the northern Texas panhandle experienced a two category improvement from moderate drought to drought-free conditions. There were also significant improvements in the eastern portions of the state, where precipitation totals for the month were well above normal. In the southernmost counties of Texas, dry conditions (continued from March) led to a slight expansion of exceptional drought.
  

• Except for small isolated pockets almost the entire western region of the continental U.S. had below normal temperatures for April 2009. On the 20th-21st a short heat spell brought all-time April records to the San Francisco and Monterey Bay areas, reaching as high as 104°F (40.0°C) at King City CA. To the north, Fairbanks, AK tied an all time April temperature record on the 29th with 74°F (23.3°C), and the next day proceeded to then break that record with 76°F (24.4°C).
  
  
• Precipitation was below normal in most of the western and southern portions of the region. Interior areas of the Great Basin, the Wasatch, parts of the central and Northern Rockies, and the plains of Montana, along with isolated pockets of southern Arizona were wetter than normal. Parts of Wyoming, Montana and Colorado had an exceptionally wet and snowy April. Great Falls, MT tied their all-time snowiest month ever with 35.4 inches (89.9 cm). Bozeman, MT also recorded their snowiest month of all time with 49.6 inches (126 cm). The large snow event along the Front Range of Colorado on the 17-19th produced 56.3 inches of snow (143 cm) in Rollinsville.
  
  
• Mountain snowpack remained mostly healthy in the Pacific Northwest and Intermountain region with snowpack on May 1st near or slightly above normal. The Southwest and California remained well below normal. Snowmelt inflow to Lake Powell on the Colorado River is expected to be near average. California snowmelt runoff is again expected to be well below average for the third consecutive year.
  

• For the month of April, temperatures averaged slightly below normal for the panhandle, southwest, and portions of the interior. The strongest anomalies were found along the Bering Sea coast with temperature departures in the 2.5 to 3.0°F (1.4°C to 1.7°C) range. Monthly means were above average in the north and parts of the interior and west-central regions. Locations on the North Slope had monthly anomalies of around 3.0°F (1.7°C). Precipitation conditions for the month showed a pattern of discontinuity with drier than normal in the east and wetter than normal in the west. Due to the gradual warm-up taking place during April with lengthening daylight hours, the seasonal snowpack disappeared or was significantly reduced at many locations.