Arizona, Southwest record hottest first half of year in 131 years, weather service says

The southwestern United States recorded its hottest January-through-June stretch since recordkeeping began in 1895, according to the National Weather Service. Every county in Arizona set an all-time record for that period.

Temperatures across Arizona ran 5 to 7 degrees Fahrenheit above the long-term average during the first six months of 2026, NWS meteorologist Ryan Worley told KTAR News 92.3 FM.

“There’s not just one aspect that’s driving these warm temperatures,” Worley said. “Throughout the winter, we didn’t see very many systems move through here, and that’s why we stayed dry. We didn’t see much rain. And when we don’t see much rain and cloud cover, we tend to stay warmer.”

Over the past 6 months, the Southwest U.S. saw the hottest Jan-June period on record since 1895. In Arizona, every county was the hottest on record as well, seeing a +5 to +7 F anomaly from the climatological average. pic.twitter.com/KeUiD3en2t

— NWS Phoenix (@NWSPhoenix) July 9, 2026

March 2026 was the warmest March in 132 years of U.S. records, with temperatures averaging 9.4 degrees above the 20th-century baseline and drought covering nearly 60 percent of the United States, according to NOAA’s National Centers for Environmental Information.

La Niña pattern kept Arizona dry and fueled record warmth

The persistent dryness that supercharged the heat had roots in the La Niña climate pattern that dominated the winter, Worley said. La Niña episodes typically steer storm systems away from Arizona, keeping winters drier and warmer than usual.

“That was another factor into why we did see drier and warmer conditions,” Worley said.

The region is now transitioning toward an El Niño episode, which historically favors above-normal precipitation across the Southwest during winter.

Worley said the shift could bring some relief.

“Maybe we’ll see a flip,” he said.

KTAR News 92.3 FM’s Kellen Shover contributed to this report. 

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