TEMPERATURES SECOND WARMEST ON RECORD FOR U.S.;
April 16, 2007 — March 2007 was more than five degrees Fahrenheit warmer than average throughout the contiguous U.S., making it the second warmest March on record, according to scientists at the NOAA National Climatic Data Center in Asheville, N.C. Precipitation was above average in much of the center of the nation, while the Southeast and much of the West were drier than average. The global average March temperature was fifth warmest on record. (Click NOAA image for larger view of March 2007 statewide temperature rankings. Please credit “NOAA.”)
Statewide temperatures were much warmer than average from parts of the Midwest and Deep South to the Northern Plains and West Coast. Most Northeast states and Florida were near average, while no contiguous U.S. state was cooler than average for the month. The month tied for the warmest on record for Oklahoma.
More than 2,500 daily record-high temperatures were set from the East to the West Coast during the month. On March 13 alone, more than 250 daily high temperature records were set. The earliest high of 90 degrees F (32 degrees C) occurred in Las Vegas that day. For March, more than 200 daily record highs of 90 degrees F or greater were registered in California, Arizona, Texas, Oklahoma and areas of the Southeast.
The warmer-than-average March temperatures helped reduce residential energy needs for the nation. 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 was approximately 11 percent lower than what would have occurred under average climate conditions for the month.
Alaska had its third coldest March on record, with a temperature 12.5 degrees F (6.9 degrees C) cooler than average. Also, 40 new daily record-low temperatures were tied, or broken, during March throughout the state.
Across the Deep South and Southeast, drier-than-average conditions prevailed for a second straight month, worsening drought conditions. Six states were much drier than average from Louisiana and Arkansas to Florida. It was the second driest March on record for Mississippi and the third driest for Alabama.
At the end of March, severe drought stretched from southeastern Mississippi to northwest Georgia and Tennessee and also affected southern Florida.
The combination of unusual warmth and below-average snowfall during much of the month led to a continued deterioration of mountain snowpack conditions in California, Arizona, Nevada and Utah.
At the end of March, mountain snowpack was less than 50 percent of average in parts of every state in the West and less than 25 percent of average in several states.
In Los Angeles, the lack of rainfall led to the driest water-year to date for the city since records began in 1877. From July 1, 2006, through the end of March, downtown Los Angeles had received only 2.47 inches of rain, almost one foot below the normal amount of rainfall for the period.
In the West, where mountain snowpack is relied upon to supply water needs throughout the region, below-average rain and snowfall have become increasingly common. In only two of the past nine years has snowpack on April 1 been at or above the long-term average in at least half the region.
Near the end of March, approximately 33 percent of the contiguous U.S. was in moderate to exceptional drought, according to the federal U.S. Drought Monitor. The most severe conditions were in northern Alabama, southern California, western Arizona, parts of the western High Plains and extreme northern Minnesota.
Separately, the global March land-surface temperature was the fourth warmest on record, while the ocean-surface temperature tied for sixth warmest in the 128-year period of record, approximately 0.2 degrees F (0.1 degrees C) cooler than the record established during the very strong El Niño episode of 1997-1998.
During the past century, global surface temperatures have increased at a rate near 0.11 degrees F (0.06 degrees C) per decade, but the rate of increase has been three times larger since 1976, or 0.32 degrees F (0.18 degrees C) per decade, with some of the largest temperature increases occurring in the high latitudes of the Northern Hemisphere.
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