June 20, 2002 The 12-month period from June 2001 through May 2002 was warmer than normal for the contiguous United States, based on preliminary data. The average temperature was 54.4 degrees F (12.4 C), 1.6 F greater than the 1895-2001 long-term mean, according to NOAA scientists at the National Climatic Data Center in Asheville, N.C. These temperatures would make this past 12-month period the 4th warmest such period on record. (Click image for larger view of NOAA's statewide temperature rankings for June 2001 through May 2002.)
The warmer-than-normal temperatures coincided with drier-than-average conditions in much of the West and along the eastern seaboard during the same period. A continuation of drier-than-normal conditions in other areas of the nation led to worsening drought conditions, most notably in the Southwest.
Extremely dry conditions have persisted in the Southwest for much of the past year. Precipitation totals in Colorado and Arizona were the lowest on record (statewide records began in 1895) during the June 2001 through May 2002 period, while New Mexico and Utah also had much below average precipitation totals.
Although the duration of the
current drought in the Southwest is less than other major droughts
of the late 19th and 20th centuries, by the first week of June
conditions for at least 80 percent of the range and pastures
in Arizona, New Mexico and Colorado were rated poor to very poor
according to the U.S. Department of Agriculture. In New Mexico,
water is flowing at less than 10 percent of average on the Upper
Rio Grande and Upper Pecos, the lowest levels in more than 75
Unlike 2000, when only 22 percent of the United States was in severe to extreme drought in early June (based on the Palmer Drought Severity Index), the same level of drought severity now affects more than 29 percent of the United States with the potential for worsening conditions as the summer begins.
Severe to extreme drought also extends from the Southwest to the Canadian border. In Montana, farmers have abandoned more than 20 percent of the winter wheat crop for the second consecutive year, the first such occurrence since 1935-36 and 1936-37. Abnormally dry conditions recently spread into agricultural areas of the northern Plains states and drought has persisted or worsened in the Southeast and along the Gulf Coast.
Drought conditions, which rapidly intensified in the Northeast during the late fall and winter due to five consecutive months (October-February) of below average precipitation, improved during the spring season (March-May). Three months of above normal precipitation totals led to rising reservoir levels in many metropolitan areas of the Northeast.
The 12-month land-surface temperature average was the warmest on record, 1.7 F (0.9 C) above the long-term mean, 0.2 F (0.1 C) warmer than the previous record warm June through May in 1998/1999. The global ocean surface temperature was 0.8 F (0.4 C) above average, the second warmest on record, and slightly less than in 1997/1998.
Land-surface temperatures were more than 2 F (1.1 C) above average on the continents of Europe and Asia, while the average temperatures from reporting stations in South America and Africa were both greater than 1 F (0.6 C) above the 1880-2001 mean during the June-May period. The average temperature in Australia was only slightly above average.
NOAA Satellite and Data Service is the nation's primary source of space-based meteorological and climate data. NOAA Satellite and Data 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 Data 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.
Relevant Web Sites