It’s January, which typically means heating bills go up as the temperature goes down. But for some people in the U.S. South, the demand will be for more air-conditioning, as temperatures soar 20 to 35 degrees Fahrenheit (11 to 19 degrees Celsius) above local averages—and even to record-breaking heights in some spots.
The unseasonal heat stems from an area of high pressure moving across the eastern U.S., pulling in warm air from the south and the record-breaking warm waters of the Gulf of Mexico.
The first records started to occur as a result of the weather system on Tuesday, with a high of 82 degrees F (28 degrees C) in Houston, Tex., 74 degrees F (23 degrees C) in Tulsa, Okla., and 81 degrees F (27 degrees C) in Baton Rouge, La.
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Wide swaths of the eastern U.S. will see temperatures well above local averages—and some could set records. In the Rio Grande Valley of Texas, temperatures could even reach 90 degrees F (32 degrees C). Brian Hurley, a meteorologist at the National Weather Service’s Weather Prediction Center, says that 31 stations across that area could set records or come close. “That’s significant,” he says.
The nights will be particularly hotter than normal—a hallmark of global warming. Overnight lows are rising twice as fast as daytime highs, according to Climate Central, a nonprofit research and news organization.
Climate Central’s Climate Shift Index tool calculates that the high temperatures seen during this January heat event have been made anywhere from 1.5 to five times more likely because of climate change, depending on the day and location.
The system follows hot on the heels of a heat wave that passed across the southern U.S. at the end of last year; December 25, 2025’s average high temperature for the contiguous U.S. was the hottest Christmas Day on record by a margin of three degrees F (1.7 degrees C). That may sound minimal, but it’s a considerable amount to set a record by, especially over such a large area.
This latest heat will be short-lived; a cold front will sweep across the U.S. ahead of a low-pressure system. Temperatures in the wake of the front are expected to return to normal.