Allergy Season Lengthens Across US

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New data from Climate Central reveals that allergy season has grown significantly longer across the United States, with the average season now lasting 21 more 'freeze-free' days compared to the 1970s. This gives plants more time to grow and release pollen, exacerbating allergy symptoms for many Americans.

Why it matters

Longer allergy seasons can have major impacts on public health, productivity, and quality of life for those who suffer from seasonal allergies. The lengthening of allergy season is directly tied to climate change, as warmer temperatures and fewer freeze days allow plants to thrive for a greater portion of the year.

The details

The data from Climate Central shows that allergy season has grown longer in every part of the country since the 1970s. This is due to the increasing number of 'freeze-free' days that allow plants to grow and release pollen for a longer period. Certain regions like the Northeast have seen allergy season expand by over a month, while other areas like the Southwest have seen more modest increases of around two weeks.

• The data analyzed changes in allergy season length since the 1970s.