Pollen isn’t the only allergen impacted by climate change. Increased humidity, heat, and flooding also create ideal conditions for mold to flourish in places where it was previously rare.

That can cause mold allergies to flare up, especially in the aftermath of climate-driven disasters like hurricanes, or for patients living in older buildings, basement units, or other homes without proper ventilation, Tummala said.

Pollen piles on

For many people, seasonal allergies are mainly a nuisance: itchy eyes, runny noses, and a seemingly never-ending cold. But pollen also messes with sleep, ups the risk of sinus infections, causes people to miss school and work, and can pose more serious dangers. A 2024 study based in Texas found that allergies can account for a significant portion of emergency department visits for asthma attacks during periods of high pollen counts.

People with allergies are also sensitive to other respiratory triggers, such as heat waves and increased air pollution, Tummala said.

On days with heavy wildfire smoke from Canada, Tummala said her patients experience the miserable effects of multiple respiratory stressors. During one such period last summer, a patient told her they were afraid to go outside.

“That’s just really sad,” Tummala said. “That’s not how you should live your life.”

Drought is another climate-intensified problem. Rain typically washes pollen out of the air. Without it, the fine powder can blow around for weeks without relief, Wees said.

For Tummala, the connection between seasonal allergies and growing climate hazards further illustrates the already pressing need for action to mitigate global warming.

“It’s a modifiable risk factor,” she said. “Climate change is something we can do something about.”

This article originally appeared on Inside Climate News, a nonprofit, non-partisan news organization that covers climate, energy, and the environment. Sign up for their newsletter here.