July 17, 2002 — Above-normal temperatures and drier than normal conditions led to a worsening drought situation across large parts of the United States in June, according to scientists at NOAA’s National Climatic Data Center in Asheville, N.C. By the end of the month, 36 percent of the contiguous United States was in severe to extreme drought, based on a widely used measure of drought severity, the Palmer Drought Index. (Click image for larger view of NOAA's January to June 2002 statewide precipitation rankings.)
The average temperature for the contiguous United States was 71.6 degrees F (22.0 C) in June, 2.3 degrees F greater than the 1895-2001 long-term mean for the month, making it the fifth-warmest June on record. Abnormally warm temperatures occurred in the Southwest and northern Plains. Colorado and Nebraska had their second-warmest June since statewide records began in 1895 while New Mexico and Nevada had their fifth-warmest June. Near-average temperatures covered much of the South and Northeast. Maine and New Hampshire had significantly cooler than average temperatures for the month.
The above-average warmth coincided with anomalously dry conditions in many areas. Fourteen states from the West Coast to the Mid-Atlantic had below average precipitation totals and four states (Arizona, Utah, Wyoming and Nebraska) were much drier than average. In the East, drought conditions were most severe in an area stretching from central Virginia to central Georgia. The past twelve months were the driest July through June on record for North Carolina and South Carolina, and drought has affected parts of the region for much of the past four years. The total precipitation deficit since July 1998 exceeded 55 inches in Greenville and 65 inches in Columbia, S.C., at the end of June.
Severe to extreme drought continued throughout large parts of the western United States from Arizona and New Mexico to Montana, significantly affecting farming and the frequence of wildfires. According to the U.S. Department of Agriculture, more than 80 percent of range and pastures were classified as poor to very poor in New Mexico, Arizona and Colorado in early July, with conditions worsening during June and early July in California, Wyoming, Nebraska, and the Dakotas.
By the end of June 2002, nearly 2.8 million acres had burned in the United States, much of it in the West, according to the National Interagency Fire Center. This acreage is almost twice the total burned during the same period in 2000, one of the worst wildfire seasons in the past 50 years. In 2000, severe to extreme drought affected 19 percent of the nation at the end of June compared with 36 percent affected in 2002. The greatest reach coverage of drought area in the nation occurred in July 1934, when severe to extreme drought covered 63 percent of the contiguous United States.
The warmest globally averaged June temperature occurred only four years ago during the last El Niño episode. Weak to moderate El Niño conditions have again formed in the equatorial Pacific and further development is likely in the coming months.
NOAA’s National Environmental Satellite, Data, and Information Service (NOAA Satellite and Information Service) is the nation’s primary source of space-based meteorological and climate data. NOAA Satellite and Information Service operates the nation's environmental satellites, which are used for weather forecasting, climate monitoring and other environmental applications such as fire detection, ozone monitoring and sea surface temperature measurements.
NOAA Satellite and Information Service also operates three data centers, which house global data bases in climatology, oceanography, solid earth geophysics, marine geology and geophysics, solar-terrestrial physics, and paleoclimatology.