September 2026 shattered the record for the hottest September ever recorded in the contiguous U.S., according to new data from the National Oceanic and Atmospheric Administration. It marks another sobering record for an already historically hot year.
This past January through September were the hottest first nine months of any year in the U.S. since at least 1895.
Overall, the contiguous U.S. averaged a balmy 69.42 degrees Fahrenheit (20.79 degrees Celsius) in September—more than 4.5 degrees F (about 2.5 degrees C) higher than the historical 20th-century average.
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Whether 2026 will break the record for the U.S.’s hottest year—currently standing at 55.48 degrees F (about 13 degrees C), set in 2024—depends on the temperatures for October, November and December. As Scientific American previously reported, climate predictions are complicated. But what is clear is that such a warm September only makes the situation more dire.
Leading up to now, the period of the first eight months of the year, January–August, was exceptionally hot. If the period of September–December averages around 50.5 degrees F (10.3 degrees C)—a warm but not unusual scenario for recent years—the U.S. is likely to break its record, climatologist Zeke Hausfather previously told Scientific American.
Crowning 2026 as the hottest year would only be part of the picture; climate change doesn’t care about records.
As Climate Central scientist Zachary Labe previously told Scientific American, “Whether 2026 ultimately ranks as number one or number three doesn’t distract from the bigger story that temperatures are rising across the country and leading to major impacts for communities.”
Editor’s Note (10/8/26): This is a breaking news story and may be updated.
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