Warming Climate Extends Allergy Season in North Carolina

Longer growing seasons mean more pollen, worse symptoms for Triangle residents

Published on Mar. 5, 2026

Got story updates? Submit your updates here. ›

Warming temperatures are extending the growing season in Raleigh, North Carolina, giving plants more time to release pollen and making allergy seasons earlier, longer, and often worse. Researchers have found the freeze-free growing season in the Raleigh-Durham area has grown by about 41 days since the 1970s, leading to longer stretches of high pollen levels and more intense allergy symptoms for residents.

Why it matters

The Raleigh-Durham area regularly ranks among the most challenging places in the country for seasonal allergies due to its dense tree canopy. As climate change continues to lengthen growing seasons, allergy sufferers in the region can expect to experience even more severe and prolonged allergy symptoms in the coming years.

The details

Climate Central's analysis of temperature data from 198 U.S. cities found the freeze-free growing season has lengthened in 87% of them since 1970, with cities gaining about three additional weeks on average. In the Raleigh-Durham area, the growing season has expanded by around 41 days. This means plants have more time to release pollen, leading to higher pollen levels and more intense allergy symptoms for residents. Sudden warm spells in late winter or early spring can also cause pollen levels to spike quickly.

  • The growing season in Raleigh-Durham has lengthened by about 41 days since the 1970s.
  • Tree pollen typically peaks in North Carolina in early spring, followed by grasses later in the spring and summer and weeds such as ragweed in the fall.

The players

Elizabeth Gardner

WRAL meteorologist

Shel Winkley

Climate Central meteorologist

Got photos? Submit your photos here. ›

What they’re saying

“When we get to the springtime, they all release pollen.”

— Elizabeth Gardner, WRAL meteorologist

“Warming temperatures are helping make allergy seasons start earlier, last longer and really just feel worse.”

— Shel Winkley, Climate Central meteorologist

What’s next

As temperatures continue to warm, scientists say allergy seasons are likely to keep expanding — meaning more days each year when pollen levels are high.

The takeaway

This case highlights how climate change is exacerbating allergy seasons in the Raleigh-Durham area, with longer growing seasons leading to more intense and prolonged allergy symptoms for residents. As the region's climate continues to warm, allergy sufferers can expect even worse conditions in the years ahead.