Sep 18, 2025 - Climate
San Diego's summers are getting longer
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Summer temperatures are hanging around longer in San Diego and nationwide, a new analysis finds, as climate change affects the seasons.
Why it matters: Temperatures staying relatively high for longer periods can increase cooling demand, prolong the risk of heat-related illnesses, and elevate the risk of wildfires.
By the numbers: In San Diego, summer temperatures now linger an average of seven days longer into fall compared to 1970, per a new report from Climate Central, a climate research group.
- The effect is similar in San Francisco (seven days), but more dramatic in San Jose (17), Palm Springs (11) and Los Angeles (10).
- Among cities with lingering heat, summer temperatures are lasting an extra 10 days on average.
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.