Almost every tract of land in the contiguous United States was warmer than normal in May, helping to break a Dust Bowl-era record.
The month’s average temperature 0f 65.4 degrees swept by the previous high mark of 64.7 degrees set in 1934. Temperatures were more than 5 degrees above normal, according to the National Oceanic and Atmospheric Administration, which published a May U.S. climate assessment Wednesday.
The 1934 record was impressive, enduring for decades even as the climate has warmed because of increasing greenhouse gases in the atmosphere. One of the main reasons May 1934 was so hot was because it was so dry, posting the least precipitation for the month on record. When the land surface is dry, it heats up faster.
A combination of drought and farming practices had left fields bare of vegetation in 1934, resulting in “an estimated 35 million acres of formerly cultivated land had been rendered useless for farming,” according to History.com.
The parched conditions were so severe that on May 11 “a massive dust storm two miles high traveled 2,000 miles to the East Coast, blotting out monuments such as the Statue of Liberty and the U.S. Capitol,” History.com wrote.
In May 2018, temperatures soared to record levels even without as much help from dry soils. Precipitation was a hair above normal averaged over the nation. Maryland, hit by major floods in Frederick and Ellicott City, had its wettest May on record. So did Florida. Asheville, N.C., posted 14.68 inches of rain, its wettest month in history.