National Climate Report - May 2004

May:

• May temperatures were above average for the nation as a whole. The mid-Atlantic region had record or near record statewide temperatures, while the northern Plains remained cooler than average. For information on temperature records during the month, please go to NCDC's Extremes page.
  
  
• The precipitation signal was mixed with wetter than average conditions in the Northwest and from Louisiana to the Great Lakes, while dry conditions prevailed in the Southeast and West. Severe storm outbreaks at both the beginning and end of the month led to a preliminary assessment of as many as 500 tornadoes occurring during May 2004. For more information on severe weather and hazards during May, please visit the Hazards page.
  
  Spring:
  
  
• Temperatures were above average nationally, during March-May, with Florida standing out as the only contiguous state that did not have significantly above average temperatures statewide. Two states (Oklahoma and Kansas) had their record warmest spring.
  
  
• The precipitation signal for spring shows dryness extending across the West and Southeast, while the Great Lakes and parts of the southern Plains and Northeast had above average precipitation.
  
  
• Details of the 2003/2004 snow season can be found on NCDC's monthly snow summary page.
  
  
• Indices used to determine the state of ENSO suggest that the Equatorial Pacific was in a neutral ENSO phase and Sea Surface Temperatures were near normal across the equatorial Pacific during May. To see the latest NOAA advisory and typical impacts of a La Nina or El Nino episode for the U.S., go to NOAA's Climate Prediction Center.
  
  For additional details, see the Monthly Highlights section. For details and graphics on weather events across the U.S. and the globe go to NCDC's Global Hazards page.

National:

• May 2004 ranked as the 15th warmest May in the 1895 to present record. The preliminary nationally averaged temperature was 62.8°F (17.1°C), which was 1.7°F (0.9°C) above the long-term mean.
• May 2004 was above average for precipitation nationally, ranking 24th wettest.
  
  For tables of national, regional, and statewide data from 1895-present, for May, last 3 months or other periods, please go to the Climate At A Glance page
  
  
• March-May temperature was also much above average and ranked as the 3rd warmest such period in the 1895 to present record. The preliminary nationally averaged temperature for March-May was 54.7°F (12.6°C) which was 2.9°F (1.6°C) above the long-term mean.
• March-May was near average for precipitation, ranking 54th wettest in the last 110 years.
  
  
• The June 2003-May 2004 temperature was much above average and ranked as the 7th warmest such period in the 1895 to present record. The preliminary nationally averaged temperature was 54.2°F (12.3°C) which was 1.4°F (0.8°C) above the long-term mean.
• Precipitation was near average for June-May, ranking 38th wettest for the last 12 months based on a record of 109 such periods.
  
  Regional and Statewide:
  
  
• May 2004 temperatures ranked much above average for 13 states including Virginia which had its warmest May on record statewide.
• Alaska temperatures were also record warm for May with an anomaly of 4.7°F (2.6°C) above the 1971-2000 mean.
• May was record wet for Michigan and Wisconsin and much wetter than average for 8 other states. Five states were much drier than average.
• The 3 month period, March-May, was significantly warmer than average for all contiguous states except Florida. Thirty states were much warmer than average including two states (KS and OK) that had a record warm spring.
• Spring temperatures were also above average for Alaska, with a statewide anomaly of 2.7°F (1.5°C) above the 1971-2000 mean.
• March-May 2004 was dry for much of the West and Southeast, while wetter than average conditions prevailed across much of the Great Lakes states. Michigan had its record wettest spring statewide.
• The last 12 months were much warmer than average for all states west of the Front Range. Temperatures in the Southeast remained near average.
• The last 12 months were record wet for 4 eastern states. Dry conditions prevailed across much of the Rocky Mountains and Pacific Northwest.

  See NCDC's Monthly Extremes web-page for weather and climate records for the month of May.
  
  An in-depth annual review of U.S. climate in 2003 is available at: http://www.ncdc.noaa.gov/sotc/national/2003/ann