Mar 10, 2026 - Climate
California is enduring longer allergy seasons
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Grab your travel pack of tissues. Allergy season is getting longer in many U.S. cities amid climate change, per a new Climate Central analysis.
- From 1970 to 2025, plants' freeze-free growing season lengthened in nearly 90% of the 198 cities analyzed.
- That's the time between the last and first freeze, used here to represent allergy season.
- In some parts of the West, the season is now between 40 to 100 days longer.