Changing Climate Lurking Behind Epic Drought and High Temps
Texas has set a new record for the hottest summer ever recorded for a U.S. state, beating a Dust Bowl-era record. Oklahoma came in a close second. Credit: NCDC.
This year, four states — Texas, Oklahoma, New Mexico and Louisiana — each had their warmest-ever June through August periods, according to weather data compiled by the National Climatic Data Center (NCDC).
For Texas and Oklahoma in particular, an ongoing severe drought contributed to such extreme heat that both states were hotter this summer than any state has ever been in any season. The average Texas summer temperature was 86.8°F, beating out the old record by more than 1.5ºF, set in Oklahoma during the Dust Bowl era in 1934. This summer, Oklahoma’s average temperature was 86.5ºF, which also exceeded the 1934 record.
The exceptional heat seen in Texas and Oklahoma this summer is largely attributed to one of the region’s worst-recorded droughts. At the end of August, more than 80 percent of Texas was still in the grips of “exceptional” drought conditions, the most severe classification, and the drought has contributed to the record-breaking temperatures as well as deadly wildfires. With far less moisture around than usual, more of the Sun's energy has been available to heat the air and drive temperatures up, rather than evaporating water out of the soil.
The past six months in Texas have each been among the top ten driest on record for Texas, says Victor Murphy, the climate services program manager for the National Weather Service’s southern region.
It is difficult for scientists to know how much global warming has contributed to this year’s sweltering conditions, but there is growing evidence that manmade climate change is leading to more frequent episodes of extreme heat. Although La Niña, a natural climate cycle, is the primary culprit for this year’s drought, research suggests that manmade climate change has been a factor in the overall drying across the Southwest in the past decade. Moreover, climate models predict that climate change may make droughts more common in the South and Southwest as the climate continues to warm.
Six U.S. states had their warmest August on record: Texas, Oklahoma, New Mexico, Colorado, Arizona, and Louisiana. Credit: NCDC.
After record-breaking temperatures roasted several states earlier this summer, August saw the mercury climb even higher in many parts of the country. Six states had their hottest August on record: Arizona, Colorado, Louisiana, New Mexico, Oklahoma, and Texas. Nationwide, last month was the second hottest August.
The blistering conditions in the southern states, combined with hot weather across the Midwest and East Coast earlier in the summer, also made this the second hottest summer on record for the entire country, second only to 1934. Since June, all but two states — Vermont and North Dakota — had at least one day where temperatures broke 100ºF. Large areas of the South and Southwest had over 55 days above the century mark this summer, and several parts of Texas and Arizona had more than 70 days when temperatures soared above 100ºF.
It wasn't warm everywhere, however. The West Coast experienced a relatively cool summer, especially in the Pacific Northwest.
In contrast to the South and Southwest, it was a wet summer across New England and the Midwest. The Northeast saw its second wettest August on record. The deluge from Hurricane Irene at the end of the month helped make this the wettest August for New York, New Jersey, Vermont and New Hampshire. In August, both New York City and Philadelphia set new all-time monthly rainfall records.