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Drone captures footage of 'popped' autumnal colors in West Virginia
Leaves on trees in Snowshoe, West Virginia, have begun changing to their fall colors, drone footage posted on Sept. 30 shows. (Credit: @snowshoemtn via Storyful)
Fall may be known for changing leaves and cooler temperatures, but across the contiguous U.S., the season is getting warmer.
A new analysis from Climate Central found that fall temperatures have increased in every county across the contiguous United States since 1970, with the fastest warming occurring in the Southwest.
Fall is warming in 98% of US cities analyzed
By the numbers:
Climate Central analyzed average meteorological fall temperatures from 1970 through 2025 in 245 major U.S. cities. Fall temperatures increased in 241 of those cities, or 98%, with an average increase of 2.9 degrees Fahrenheit.
The Southwest experienced the largest average increase, warming 4.2 degrees over the period. The Northern Rockies and Plains followed with an average increase of 3.9 degrees.
Fall temperatures have risen in every county across the contiguous U.S. since 1970, Climate Central found. (Credit: Getty Images)
The warming isn't only showing up in seasonal averages. Many cities are also experiencing more individual fall days that are warmer than normal.
Climate Central found that 240 of the 245 cities analyzed – 98% – have experienced an increase in the number of warmer-than-normal fall days since 1970.
In fact, in 216 cities, or 88%, residents now experience at least seven additional warmer-than-normal fall days compared with the early 1970s.
Reno, Nevada sees largest increase
Dig deeper:
But some cities have seen substantially greater changes.
Reno, Nevada, had the largest increase, with fall temperatures rising 7.9 degrees since 1970. El Paso, Texas, followed at 6.9 degrees, while Las Vegas warmed 6.3 degrees. Tyler, Texas, and Tucson, Arizona, rounded out the top five, with increases of 6.0 and 5.9 degrees, respectively.
The broader county-level trend is equally striking: every county in the contiguous U.S. has experienced fall warming since 1970.
Climate change leading driver of fall warming
Big picture view:
Using Climate Central's Climate Shift Index attribution science, researchers also found that human-caused climate change was the leading driver of fall warming in 200 of the 245 cities analyzed – about 82%.
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In those cities, human-caused climate change accounted for at least half of the observed warming since 1970.
In 41% of the cities, researchers found that human-caused climate change could explain all of the observed fall warming.
Meteorological fall starts Sept. 1
Why you should care:
The findings come as meteorological fall begins Sept. 1. Unlike astronomical fall, which begins with the autumnal equinox, meteorological fall is defined as September, October and November based on seasonal weather patterns.
According to Climate Central, this summer’s extreme heat is likely to linger through fall with above-normal temperatures expected across the U.S. in the months ahead.
The Source: This Climate Matters analysis is based on open-access data from the National Oceanic and Atmospheric Administration (NOAA). This story was reported from Los Angeles.