Longer pollen seasons worsen allergies, causing runny noses, itchy throats, and respiratory issues among millions of people

Nearly 90% of the 198 US cities analyzed by Climate Central have witnessed longer allergy seasons. Climate change can be blamed for the phenomenon.

Between 1970 and 2024, the freeze-free growing season has extended by an average of 20 days, allowing plants to release more pollen.

Increased pollen means worse allergies, with symptoms like runny noses and itchy throats affecting millions in America.

Some of the biggest increases happened in Reno, Nevada, which saw 96 more freeze-free days. Others include Myrtle Beach, South Carolina (52 days) and Toledo, Ohio (45 days).

In contrast, Waco, Texas and Tulsa, Oklahoma, saw a 14-day decrease, while Denver, Colorado, lost 8 days.

Rising carbon dioxide levels also boost pollen production, especially in grasses and ragweed. A 2022 study warns that rising CO2 pollution could dramatically increase nationwide pollen levels, making symptoms even more severe.