Last Update: 04/05/2026 at 2:50 PM EST
Warming Extends Allergy Seasons
Coverage from The Invading Sea, Warmer Growing Season, and others
Articles
12
Latest Article
04/01
Active Days
29
Executive Summary
Warming temperatures are lengthening pollen seasons across the US, worsening allergy and asthma symptoms for millions of people
- Climate Central found freeze-free growing seasons have lengthened in all U.S. climate regions since 1970
- The Northwest saw the largest average increase, with about 31 more freeze-free days
- Most of the 198 U.S. cities analyzed gained about 21 days of growing season on average
- Raleigh, Philadelphia, and Tallahassee saw major allergy season lengthening, while Allentown was an exception
- Earlier spring growth gives trees, grasses, and weeds more time to release pollen
- Higher heat-trapping pollution can also raise pollen production and intensify symptoms
- Longer pollen seasons can worsen asthma and hit children and other sensitive groups hardest
Quick Facts
- What: Warming is extending pollen seasons and increasing allergy burden
- Where: Across all U.S. climate regions and many cities
- Why: Rising temperatures and carbon pollution give plants more time to grow
- Who: Climate Central and allergy sufferers across the United States
- When: From 1970 through 2025, with early 2026 spring signs
Coverage Timeline: 29 Days
Featured Article
Climate Central reports warming temperatures since 1970 lengthen pollen seasons across the United States, with health impacts linked to higher pollen production.
Additional Articles
⭐⭐⭐⭐⭐
Climate Central reports longer allergy seasons in the United States.
⭐⭐⭐
Climate change is linked to longer and more severe pollen seasons in the U.S., with the Asthma and Allergy Foundation of America ranking Boise, San Diego, Tulsa, Provo, and Rochester as hardest-hit cities this year.
Climate Central reports longer allergy seasons across the United States from 1970 to 2025 in 173 of 198 cities.
Researchers and allergists link longer and more intense U.S. allergy seasons to climate change and provide exposure and medication guidance in Atlanta-area reporting.
Climate Central reports that the freeze-free period lengthened from 1970 to 2024 across 198 US cities.
AccuWeather projects earlier and more intense pollen seasons across the United States in 2026 due to warming temperatures and changing precipitation.
Rebecca Saff of Massachusetts General Hospital reports climate warming and pollution shift allergy seasons, expand allergen ranges, and increase respiratory risks in the United States.
Climate Central reports Raleigh North Carolina shows allergy season lengthening from 1970 to 2025 due to warming temperatures.
NYU Langone Health and Hackensack Meridian Health allergists report climate change is starting pollen seasons earlier, increasing allergy severity and downstream health impacts in the US.
Climate Central analysis links Seattle-Tacoma’s roughly 12-day-longer allergy season since 1970 to climate-driven increases in freeze-free days and pollen exposure.
Allergy seasons in the United States are arriving earlier and lasting longer due to climate change, increasing health risks and the need for local pollen monitoring.