Summer temperatures are hanging around longer nationwide compared to the early 1970s, a new analysis finds, as climate change affects the four seasons.
Why it matters: Temperatures staying relatively high for longer periods can increase cooling demand, make life miserable for teachers and students in rooms without A/C, mess with farmers' growing seasons, and prolong the risk of heat-related illnesses.
- Longer summers also elevate the risk of wildfires by drying out vegetation and soil, creating more fuel for blazes.
Driving the news: Summer temperatures are lingering compared to 1970 in just over 90% of the 246 U.S. cities analyzed in a new report from Climate Central, a climate research group.
- Among cities with lingering heat, summer temperatures are lasting an extra 10 days on average.
Zoom in: Summer temperatures are lasting for the most extra days in Wheeling, West Virginia (52 more days compared to 1970); Miami (46 more days) and San Angelo, Texas (31 more days).
The other side: Some cities show the opposite trend, including Myrtle Beach, South Carolina (11 fewer days); Washington, D.C. (8 fewer days) and Charlottesville, Virginia (8 fewer days).
How it works: Climate Central's analysis is based on NOAA data, and reflects the last date each year with highs equal to or greater than historical summer-like temperatures.
- The group defined "summer-like temperatures" as the 75th percentile of daily highs during the 1991-2000 climate normal.
- "In other words, summer-like temperatures represent the hottest quarter of the year during 1991-2020."
What they're saying: "Research suggests that high future levels of heat-trapping pollution would cause summers to continue to stretch longer and later in the coming decades — putting health, ecosystems, and agriculture at risk," per the report.
- The group also highlights previous research showing that climate change is lengthening summers across the Northern Hemisphere.
What's next: NOAA's seasonal outlook for September through November calls for above-normal temperatures for most of the country, especially in the Northeast, Southwest and much of Florida.
