Thermometers climbed above 100 Tuesday; Tallahassee had only trace amounts of rainfall in September

Across the South, residents and farmers are facing a double punch of hot temperatures and drought even as the calendar has flipped to fall.

The thermometer hit 101 degrees in Montgomery, Ala., on Tuesday, breaking the record by 6 degrees. Twice last month, the city saw a high of 103.

Official government tallies for September aren’t in yet, but dozens of cities across the country are expected to break records, especially in the Southeast.

Heat Wave

On Tuesday, record highs were set across the region, with temperatures sitting in the high 90s in cities including Nashville, Tenn., Tallahassee, Fla., and Louisville, Ky. Meridian, Miss., hit a sweltering 101.

In Atlanta, the high hasn’t dipped below 90 degrees for 10 days.

The unusual heat wave comes after this summer tied for the hottest on record for the Northern Hemisphere, according to the National Oceanic and Atmospheric Administration. Scientists say the string of warm months suggests this year will be among the five hottest on record.

The triple-digit daytime highs have combined with an acute lack of rainfall to rapidly dry out much of the Southeast, causing what is known as a “flash drought,” according to climatologists and government agencies.

Rainfall totals in the Southeast have been less than 40% of their normal average in the past 60 days, according to the U.S. Drought Monitor, jointly produced by NOAA, the U.S. Department of Agriculture and the National Drought Mitigation Center at the University of Nebraska-Lincoln.

“The same stubborn high-pressure ridging that has been predominant over the Southeast U.S. has brought record high temperatures, a drier air mass and lack of rainfall,” said David Zierden, state climatologist for Florida, at Florida State University. “So it is all tied together.” Related Reading

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The region now ranges from “abnormally dry” and “moderate drought” to “severe drought,” the first three stages of a five-stage drought scale.

For all of September, Tallahassee had barely any measurable rainfall, making it one of the city’s driest months on record. The last time it significantly rained there was late August. The monthly average for September in the past five years has ranged between 3 and 7.6 inches.

“This flash drought is already impacting agriculture, damaging range and pasture grasses for livestock and making it difficult to harvest peanuts in the dry, hard soils,” said Mr. Zierden.

If drought conditions continue, it could bring wildfires and render entire crops as losses.

“It’s not good for the quality of cotton, at all. It’s not going to be as good of a crop, that’s for sure,” said Dan Simmons, manager at Sanders Farm Service in Vienna, Ga.

Mr. Simmons, who harvested cotton in the upper 90 degrees on Thursday, said the continued heat could also damage cover crops, which often are planted to enrich the soil, prevent erosion or suppress weeds. That could hurt future yields.

“Hot and dry is perfect for harvest, but this heat is unreal for a month like October,” he said. "We just need some rain.”

Temperatures are expected to drop across the Southeast ahead of the weekend, as a cold front makes its way east, but chances of rain remain slim.