State of the Climate
National Overview
December 2004

December:

• December temperatures were above average across much of the western U.S. and in particular in the northern Rockies. Near average temperatures were evident from the South to the Northeast. For information on temperature records during the month, please go to NCDC's Extremes page
• The precipitation signal was mainly wet across the Southwest and Northeast with the central U.S. and parts of the Southeast to Mid-Atlantic states as well as portions of the Northwest remaining drier than average for the month. For more information on drought during December, please visit the U.S. Drought page.
• Indices used to determine the state of ENSO suggest that the Equatorial Pacific was in a weak warm phase (El Niño), with Sea Surface Temperatures continuing above normal across the central equatorial Pacific during December. To see the latest NOAA advisory and typical impacts of a La Niña or El Niño episode for the U.S., go to NOAA's Climate Prediction Center.

National:

• December 2004 ranked as the 23rd warmest December in the 1895 to present record. The preliminary nationally averaged temperature was 35.7°F (2.1°C), which was 2.2°F (1.2°C) above the long-term mean.
• December 2004 had near average precipitation, nationally, ranking 42nd driest.
• October-December temperature was above average and ranked as the 11th warmest such period in the 1895 to present record. The preliminary nationally averaged temperature for October-December was 45.5°F (7.5°C) which was 1.9°F (1.1°C) above the long-term mean.
• October-December had much above average precipitation, ranking 6th wettest in the last 110 years.
• The January-December 2004 temperature was above average and ranked as the 24th warmest such period in the 1895 to present record. The preliminary nationally averaged temperature was 53.5°F (11.9°C) which was 0.7°F (0.4°C) above the long-term mean.
• Precipitation was above average for January-December, ranking 6th wettest for the last 12 months based on a record of 110 such periods.
  
  Regional and Statewide:
  
  
• December 2004 temperatures ranked much above average for 3 western states. A further 16 states in the contiguous U.S. had above average temperature.
• Alaska temperatures were above average for December ranking 15th warmest since 1918 with an anomaly of 4.5°F (2.5°C)
• December was wetter than average for 14 states, and drier than average for 17 states including South Dakota and Nebraska which had much below average precipitation.
• The 3 month period, October-December, was warmer than average for much of the nation. Only 9 states were near average and no state was significantly cooler than average for the most recent 3 months.
• October-December 2004 was wetter than average for much of the country, with 12 states having a much wetter-than-average 3 months.
• January-December 2004 was warmer than average for much of the nation. Only 11 states in the contiguous U.S. were near average for temperature and only Maine was significantly cooler than average over the last year.
• The last 12 months were much wetter than average for 10 states, with Pennsylvania having its 2nd wettest year.

  See NCDC's Monthly Extremes web-page for weather and climate records for the month of December.