Sneezing in March? Why allergies feel worse than ever, and what you can do

The climate crisis is lengthening allergy season in some US cities – and intensifying the allergen content of pollen

An uncharacteristically warm winter in the US has brought on the earliest spring on record across parts of the US. And from New York to Seattle to the deep south, pollen is already prompting sneezing and scratchy eyes for allergy sufferers. Climate change is in fact intensifying allergy season across North America, and has lengthened it by an average of 20 days. In some places, though, it is even longer than that.

Which cities have it worst, why do scientists think allergies are becoming even more unbearable, and what can we do to manage them?