Here's how climate change is worsening allergies across SC
Since saying goodbye to winter, Charleston has become a pollen-coated nightmare. Long-term, experts warn it’s going to get worse.
The Holy City’s “freeze-free” season has gotten an average of 32 days longer since 1970 due to a warming climate, according to a new report from the advocacy nonprofit Climate Central.
TJ Green of North Charleston washes his truck at Rivers Avenue Car Wash, Tuesday, March 18, during a late winter stretch featuring high pollen. Green said this is the second time this year he’s washed his truck, and is working on removing a layer of pollen and some fresh tree sap he found this morning.
Robert Scheer/StaffMore freeze-free days means a longer pollen season that also arrives earlier. That, in turn, translates to more headaches, scratchy throats, runny noses and general suffering for Holy City residents with allergies. (It’s about one out of every four adults, Climate Central reports.)
A Bradford pear blossom showing the pollen-containing stamen, Tuesday, March 18, during a rough late winter for seasonal allergy sufferers. These oft-maligned ornamental trees are insect-pollinated and don’t shed pollen to the wind, so they’re largely not to blame for sneezing and runny eyes due to allergies.
Robert Scheer/StaffThe increasing length of Charleston’s freeze-free season outstrips the average. Across the 172 U.S. cities analyzed by Climate Central, the average freeze-free season length has increased by 20 days. The Holy City is still far from the worst. In Reno, Nev., the freeze-free season has grown by 96 days since 1970.
Another report published March 18 by the Asthma and Allergy Foundation of America found that a warmer world also is boosting the intensity of allergy season. The nonprofit’s 2025 Allergy Capitals report found that the southern and eastern U.S. were particularly vulnerable to that trend. The Environmental Protection Agency predicts South Carolina’s hot summers, which also boost pollen emissions, will worsen in the future.
“It’s really kind of creating this perfect storm of longer and more intense allergy seasons,” said Hannah Jaffee, the Foundation’s research director. A separate, 2022 peer-reviewed study estimated that, by the end of this century, climate change could drive a 200 percent increase in pollen emissions.
In the near term, AccuWeather forecasts that a wet and hot summer will result in above-average pollen levels across 39 states this year.
The 2025 allergy season in South Carolina will see higher-than-average weed pollen later this summer. Grass pollen levels are forecast to be lower than average at the summer peak. Tree pollen levels — which already have peaked, hence the yellow dust coating everyone’s car — are about average.
Tiny flecks of pollen collect on a car’s roof, Tuesday, March 18, during a rough late winter for seasonal allergy sufferers.
Robert Scheer/Staff“There will be variability year to year depending on spring temperatures, storm tracks, and additional moisture from tropical storms and hurricanes, but the overall trend is clear,” AccuWeather Senior Meteorologist and Climate Expert Brett Anderson wrote in the forecast. “Pollen counts are on the rise and seasonal allergies are getting worse for millions of people as our climate continues to warm.”
Charleston’s allergy problems could be worse still. Jaffee said the coastal breeze helps clear out allergens, making it a bit easier for residents here to breathe easy. Greenville, on the other hand, earned a top-spot on the 2025 Allergy Capitals report — coming in ninth worst in the nation for seasonal allergy sufferers, due to a high presence of tree, grass and weed pollen.
Gesundheit!