Fall used to mean pulling out sweaters by early October. Now I’m still in shorts well into November some years. Climate Central just released data showing this isn’t just happening where I live – it’s everywhere across the US.
Every single county has warmer falls now compared to 1970. We’re looking at 2.8°F (1.6°C) higher temperatures on average when they checked 237 cities. So those cool October mornings? They’re happening later now, or sometimes not at all.
The Southwest leads the pack with increases of 4.0°F (2.2°C). After that comes the Northern Rockies and Plains at 3.5°F (1.9°C). Some places really stand out – Reno is 7.7°F (4.3°C) warmer than it used to be. El Paso jumped 6.5°F (3.6°C), Las Vegas 6.2°F (3.4°C). Up north, the Upper Midwest is up 3.3°F (1.8°C). The Southeast has the smallest changes at 1.9°F (1.1°C), but it’s still warmer there too.
Climate Central created this county-level map showing the changes. Lighter colors show increases around 1°F (0.6°C), dark red shows 5°F (2.8°C) or more warming.
The data comes from NOAA’s climate records – their nClimDiv dataset tracks monthly county temperatures. Those deep red areas concentrated in Arizona and New Mexico really stand out.
I made an interactive version where you can click any county to see its exact temperature change since 1970, displayed in both Fahrenheit and Celsius.
These changes affect daily life in lots of ways. Trees hold leaves longer, bird migration gets disrupted. More bugs survive mild winters. Farmers extend growing seasons. Cities like Phoenix stress power grids with longer heat periods. Water loss from reservoirs gets worse.
Climate Central has the complete dataset going back decades.
Their website has more charts and city breakdowns if you want to dig deeper.
What autumn changes have you noticed? I’m curious about seasonal shifts people are seeing, whether in the US or elsewhere.
