Warmer- and drier-than-average conditions dominated much of the United States during the first half of 2007, according to scientists at NOAA's National Climatic Data Center in Asheville, N.C. The lack of precipitation led to widespread drought which contributed to an early start to the wildfire season, mounting crop losses, and local drought emergencies. However, drought in the southern and central Plains gave way to heavy and persistent rains which led to devastating flooding from Texas to Kansas in June. Meanwhile, the global average temperature was the second warmest on record for the January-June six-month period.
U.S. Temperature Highlights for June
For the contiguous United States, the first half of 2007 was the 18th warmest January-June since records began in 1895. The six-month mean temperature was 1.3° F (0.7° C) above the 20th century average of 48.4° F (9.1° C).
Temperatures were much warmer than average from the mid-Atlantic and Midwest to the northern Plains and throughout the West. In the contiguous U.S. only Texas was cooler than average while near-average temperatures were widespread across the South and Northeast. Alaska was 0.3° F (0.2° C) below the 1971-2000 mean for the January-June period.
June 2007 was the 23rd warmest June on record, 1.4° F (0.8° C) above the 20th century average of 69.3° F. The warmer-than-average June temperature helped increase 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 1.5 percent higher than what would have occurred under average climate conditions for the month.
U.S. Precipitation Highlights for June
The year began with widespread severe drought in the southern and central Plains, Wyoming, the western High Plains, and northern Minnesota. Above average precipitation helped ease or end drought in many of these areas by mid year, but this was not enough to overcome an extremely dry winter and spring throughout most of the West. Meanwhile, much-below-average precipitation caused drought to develop in the Deep South.
Four of the first six months of the year were wetter, or much wetter, than average in Texas, Oklahoma, and Kansas. The wet period was punctuated by heavy and persistent rains in June that produced devastating flooding in the region and the continued threat of flooding into early July. Monthly rainfall totals exceeded one foot in some locations.
Much of the West and the South suffered from extreme drought conditions brought about by months of below average precipitation.
An extremely low winter and spring snowpack throughout the West combined with above average temperatures in the spring and early summer set the stage for an early start to the wildfire season.
It was the second driest January-June and driest April-June on record in the Southeast. By the end of June, 65 percent of the region was in drought. Alabama was hardest hit, with 86 percent of the state's pasture and range lands in poor--or very poor--condition in early July according to the U.S. Department of Agriculture. The entire state was declared a drought disaster area.
Global Highlights
The combined global land and ocean surface temperature was the second warmest on record for the January-June six-month period. Separately, the global January-June land-surface temperature was warmest on record, while the ocean-surface temperature was the sixth warmest in the 128-year period of record.
For June, the global land and ocean surface temperature was the fourth warmest on record as neutral El Niño/Southern Oscillation (ENSO) conditions contributed to an overall lower global ranking for the month.
Above average temperatures covered much of the world's land surfaces during the first half of the year. While some land areas in the Southern Hemisphere began the June-August winter season with below average temperatures, it was the warmest June on record at the South Pole.
