Coldest U.S. temperatures are rising
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Thirty-year average coldest temperatures are rising almost universally nationwide, a new analysis found.
Why it matters: Such a shift can affect us in a variety of ways — changing which plants and insects thrive in our neighborhoods, for example, amid other impacts of climate change.
- Much of the U.S. was categorized into warmer plant hardiness zones with the latest USDA map update in 2023, as Axios' Jacque Schrag reported at the time.
Driving the news: The 30-year average coldest temperature for 1995-2024 compared to 1951-1980 was higher in 97% of the 243 locations analyzed by Climate Central, a research and communications group.
- Among the locations with an increase, the coldest annual temperature was 3.7°F higher on average.
- The group's analysis is based on data from NOAA's Regional Climate Centers.
Zoom in: Reno, Nevada (+9.7°F); Anchorage, Alaska (+9°F) and Traverse City, Michigan (+9°F) had the biggest increases in average coldest temperature between the two 30-year periods.
- Watertown, New York (-4.0°F); Denver, Colorado (-2.2°F) and Casper, Wyoming (-1.3°F) saw the biggest decreases.
Zoom out: "Averaged regionally, the coldest temperatures have warmed the most in cities across Alaska (+7.8°F), the Northwest (+4.7°F) and the Southwest (+4.3°F)," Climate Central notes.
What they're saying: "Although such shifts could expand growing ranges for high-value crops such as almonds, oranges, and kiwis, they could also expand ranges for harmful weeds and pests," Climate Central says, citing the invasive kudzu vine and the brown marmorated stink bug.
What's next: The group also used climate modeling and NASA data to project future change between the 1995-2024 30-year period and the 2036-2065 period.
- It predicts that the 30-year average coldest temperature will rise in every single one of the 243 locations analyzed between those periods, with an average gain of 5.6°F.
