What is in this article?:
- Extremes punctuated April weather across U.S.
- Above normal temperatures
• Fueled by record-setting precipitation totals, historic and near-historic flooding occurred throughout the Midwest and Ohio Valley, from the smallest streams to the largest rivers.
• Several violent tornado outbreaks impacted the country during April.
• Much of the southern and eastern U.S. experienced above-normal warmth in April.
Extremes punctuated April weather across U.S.
Above normal temperatures
• Much of the southern and eastern U.S. experienced above-normal warmth in April. Based on preliminary data, Delaware had its warmest such month on record. It was the fourth warmest April for Virginia and the fifth warmest for Texas. Other states with much above normal warmth include: Florida and Louisiana (seventh warmest), New Mexico and West Virginia (eighth), New Jersey (ninth) and Maryland (10th).
• The Northwest was much cooler than normal during April. Washington State (second coolest, five degrees F below their long-term average), Oregon (fifth coolest) and Idaho (10th coolest) were all much cooler than normal.
U.S. Climate Highlights February – April
• The Northeast and Ohio Valley regions had the wettest February-April period on record. Indiana, Kentucky, Ohio, New York, and Pennsylvania set precipitation records. Other states with much-above-average precipitation for the period were: West Virginia (second wettest), Illinois and Vermont (third), Michigan (fifth), Missouri (sixth), and Washington (ninth).
• Exceptionally dry conditions have parched the soil and vegetation in Texas, which has recorded precipitation of just 1.68 inches on average across the state since Feb. 1. This is the driest February-April period on record for Texas, nearly an inch less than the previous record (2.56 inches, February-April 1996). Also much drier than normal were New Mexico (seventh driest) and Louisiana (eighth driest).
• Temperatures during the February-April period, when averaged across the nation, were near the 20th century average. However, the Northwest was cooler than normal, while the South and East coasts were above- to much-above normal.
• According to NOAA’s Climate Prediction Center, La Niña conditions continued through April 2011 and are expected to transition to neutral conditions by early summer. The February-April U.S. temperature and precipitation patterns were largely consistent with those commonly associated with an early spring La Niña episode.
Previous 12 months
• The rolling 12-month (May 2010-April 2011) period shows record wetness for Minnesota, North Dakota and Wisconsin which has contributed to flooding along rivers and streams in that region. The Great Lakes region had its wettest such period and it was much above normal in the Northeast, Central, Upper Great Plains, Northern Rockies and Northwest.
• Above average warmth has occupied much of the nation during the 12-month period. Only the Northwest has experienced average temperatures that were below the 20th century average.
• The year-to-date January-April period average precipitation has been above- to much-above normal across the northern tier of the country. Record precipitation averages in New York and Pennsylvania contrasted with the third driest such periods in Texas and New Mexico.
NCDC’s State of the Climate analyses, which assess the current state of the climate, are released soon after the end of each month. They are based on preliminary data, which are subject to revision. Additional quality control is applied to the data when latereports are received several weeks after the end of the month and as new scientific methods improve NCDC’s processing algorithms.