Mapped: The fastest-warming regions across the U.S. during spring
Spring is getting warmer overall and featuring more unusually hot days in most U.S. cities, a new analysis finds.
Why it matters: Warmer springs can cause early snowmelt, which can imperil summer water resources and heighten wildfire risks.
- Warmer springs can also worsen allergies, among other effects.
Zoom in: Nonprofit climate research and communications organization Climate Central examined 55 years of U.S. temperature data for 241 cities and found that the meteorological spring season of March through May has warmed by a national average of 2.4ยฐF.
- In an analysis released Wednesday, the group found that 97% of the 241 cities analyzed saw a warming trend for the season.
- Four out of every five cities now see at least one more week of warmer-than-average spring days compared to the 1970s.
- The geography of the warming across the U.S. shows that the fastest rates are in the southern tier, with the Southwest leading the pack at an average spring warming of 3.4ยฐF.
By the numbers: The cities that have warmed the most since 1970 were Reno, Nev., which has seen average seasonal temperatures spike by 6.8ยฐF, followed by El Paso, Texas at 6.4ยฐF and Las Vegas at a seasonal average temperature increase of 6.1ยฐF.
- Tucson, Albany, Ga., Chattanooga, Tenn. and Phoenix round out the fastest-warming list in the analysis.
- While the Southwest is the region seeing the fastest-warming spring, the fall actually outranks spring for the fastest-warming season in much of the Southwest and West.
- And winter is the fastest-warming season for much of the Central and Eastern U.S., along with Alaska.
Yes, but: One region of the U.S. has seen some cooling during spring.
- It stretches from northern Montana into North and South Dakota as well as a sliver of Minnesota.
The intrigue: As spring temperatures have increased, the average number of days with above-average temperatures also went up in 98% of the locations analyzed.
- Locations in the Southwest, West, Southeast and South had the greatest increase in the average number of warmer-than-average spring days since 1970.
- Tampa, for example, now has an average of 37 more days with hotter-than-normal spring temperatures, Climate Central found.
Between the lines: The spring warming in the U.S. is taking place in tandem with increasing temperatures around the world due to human emissions of greenhouse gases from burning fossil fuels such as coal, oil and gas.