Sneezy season is back with a vengeance

It's time to stock up on Claritin and Flonaze: pollen season is back, and getting longer and more intense in many parts of the country.

Experts say 2026 could bring one of the worst seasons on record for the ~25% of Americans with seasonal allergies, with rising pollen production fueled by shifting climate patterns.

The season already began a week ahead of schedule in parts of the US Southeast, with early starts for allergy symptoms also expected in the Southwest, Northeast, and Pacific Northwest.

An ongoing trend

North American pollen seasons have lengthened by ~20 days since 1990, and now range from ~4.5 months in the US South to ~8 months in the Northern Rockies and Plains. Overall, pollen concentration in North America has increased by 21% over the same period.

There are a few explanations. Warmer weather and fewer freeze days are extending growing seasons across the US, giving plants more time to bloom and release pollen. Higher carbon dioxide levels over the years have also boosted pollen levels and intensified allergy symptoms.

On the bright side, there’s at least one seasonal perk. Parts of the US will gain three or more hours of daylight between the recent spring equinox and the summer solstice on June 21.