June 19th, 2006 16:23 EST
Global Temperature Warmer Than Average
June 19, 2006 — The contiguous United States experienced its fifth warmest May and fourth warmest spring since records began in 1895, while overall precipitation remained below average, according to scientists at the NOAA National Climatic Data Center in Asheville, N.C. Also, the June 2005 - May 2006 period was the warmest on record for the contiguous U.S. The continuation of below-normal precipitation combined with much warmer than average temperatures led to persistent, or in some cases worsening, drought conditions in many parts of the nation. Meanwhile, portions of New England experienced flooding in May, as a series of storms set many local rainfall records. The global surface temperature was fifth warmest on record for May. (Click NOAA illustration for larger view of May 2006 weather. Please credit “NOAA.”)
The average temperature for the contiguous United States for May (based on preliminary data) was 63.7 degrees F (17.6 degrees C), or 2.7 degrees F (1.5 degrees C) above the 20th century (1901-2000) average. The March-May period was the fourth warmest spring for the contiguous U.S, and four states (Arkansas, Oklahoma, Kansas and Texas) experienced their warmest spring on record. No state had below average spring temperatures, and only California was near average. This continued the string of warmer-than-average conditions over the past year in the contiguous United States. (Click NOAA image for larger view of May 2006 statewide temperature rankings. Please credit “NOAA.”)
Since the start of last summer, six months have been much warmer than average, including two months (January and April 2006), which were warmest on record. The 12-month period was the warmest on record. The anomalous warmth has covered all parts of the country, with statewide records established in Iowa, Maryland, Michigan, Minnesota, New Jersey, New Mexico, New York, North Dakota, Vermont and Wisconsin. For Alaska, eight of the past twelve months were warmer than average, and the June-May temperature was the 20th warmest since records began in 1918.
May 2006 precipitation across the contiguous United States was below average, at 2.33 inches (59 mm), 0.54 inches (14 mm) below the 20th century average. Most of the central U.S. was drier than normal, but only Nebraska and Iowa were much drier than average. A series of storms in the northeastern U.S. resulted in well-above normal rainfall totals from Michigan and Indiana across to New England. New Hampshire and Massachusetts both experienced their second wettest May on record. This is largely due to the exceptional rainfall event of May 10-15, when accumulations of between 12 and 17 inches (300-430 mm) of rain occurred in some localities. (Click NOAA image for larger view of May 2006 statewide precipitation rankings. Please credit “NOAA.”)
Spring 2006 also was drier than average for the contiguous United States, with the most anomalously dry conditions along the eastern seaboard from New Jersey to Florida. Areas from the Gulf Coast to Wyoming also were drier than average. Parts of the Far West, northern Rockies and Midwest, along with Vermont and New Hampshire were wetter than average.
Persistent drier-than-average conditions over the past several months, combined with much above average to record warmth, worsened drought conditions. By early June, moderate-to-severe drought was present throughout a large part of the south-central U.S., with extreme and exceptional drought occurring in the parts of the Desert Southwest, southern Plains and southeastern Louisiana, according to the U.S. Drought Monitor. Moderate drought developed in central Florida and grew to encompass parts of the southern Appalachian region. Fully 39 percent of the contiguous United States was in moderate-to-extreme drought, while 20 percent was in severe-to-extreme drought, as defined by the Palmer Drought Index, a widely-used measure of drought. Above average precipitation alleviated moderate drought conditions in the Upper Peninsula of Michigan, and conditions improved in areas that included eastern Oklahoma, southern Florida and parts of the Northeast.
The eastern North Pacific Hurricane season officially began May 15, and Tropical Storm Aletta formed southwest of Acapulco, Mexico, May 27. Aletta reached maximum sustained winds of 40 kt (45 mph) and a central pressure of 1002 mb before moving out to sea and dissipating May 30.
This was the fifth warmest May globally since records began in 1880 (0.90 degrees F/0.50 degrees C above the 20th century mean) for global land and ocean surfaces, and sixth warmest boreal spring (March-May) (0.92 degrees F/0.51 degrees C). The warmest March-May occurred in 2005 (1.19 degrees F/0.66 degrees C above the 20th century mean). Land surface temperatures for May were above average across southern Europe and Scandinavia, eastern and southwestern Asia, and much of North America. Unseasonably cold May weather occurred in central South America, as well as in South Africa and Lesotho, where an uncommon mountain snowfall occurred. An early May heatwave produced temperatures over 104 degrees F (40 degrees C) across India, claiming more than 50 lives.
NOAA, an agency of the U.S. Department of Commerce, is dedicated to enhancing economic security and national safety through the prediction and research of weather and climate-related events and providing environmental stewardship of the nation's coastal and marine resources.
Through the emerging Global Earth Observation System of Systems (GEOSS), NOAA is working with its federal partners, 61 countries and the European Commission to develop a global network that is as integrated as the planet it observes, predicts and protects.
Relevant Web Sites
Climate of 2006: May in Historical Perspective, Including Boreal Spring