Usually it's the springtime when pollen allergies cause itchy eyes, sneezing and nasal congestion. But those symptoms can also stretch well into the warm summer months and beyond.
Recent data show those allergens have been a lot worse than normal in San Diego.
“Our patients have definitely complained of feeling their symptoms much more in the last few years,” said UC San Diego Health Assistant Professor of Medicine Dr. Christine James.
Out of the largest 100 cities in the contiguous United States, a 2026 report from The Asthma and Allergy Foundation of America showed San Diego went from third best to second worst city for people dealing with allergies.
“From what we saw with our pollen seasons, we saw that they were peaking earlier, the amount of pollen that was being produced is larger and the seasons themselves are longer,” James said.
Compared to previous years, the report had more cities in the western U.S. placed in the top 20 allergy capitals.
The report said that’s in part due to climate change. Weather occurrences like atmospheric rivers, warmer temperatures, and drought play a role in higher pollen production.
James said San Diego got a lot of that weather in the past few years.
She said what sets San Diego apart from many other areas is the lack of a true cold winter season, leading to near constant exposure of different types of pollen.
“I think the way to think about the seasons, you know trees in San Diego really come up in December-January, they go through spring," James said. “Then you have your grasses that will come up in late spring and go through summer. And then weeds come up in late summer and go through fall.”
Due to climate change, storms are becoming more extreme and atmospheric rivers are likely to drop large amounts of water at once.
Heavier rains can lead to more weed growth, which Scripps Clinic Allergy Center Director Dr. Ronald Simon said is the main culprit behind the increased pollen count for San Diego.
“I think the reason the weeds have really jumped up, and I think that's the thing that's made the biggest difference, is the way we have our rains now,” Simon said.
Allergists said there are ways to help with pollen exposure.
That includes tracking pollen forecasts through websites and apps and staying indoors when counts are high; wearing sunglasses, hats and even masks as needed; and immediately washing clothes when getting home.
They also said using a certified HEPA filter in air purifiers can reduce impacts indoors. For those with access to air conditioning, they said keep windows closed when pollen counts are high.
“These pollens are allergenic because they are very light, they can get blown for miles and miles and get into our noses, eyes, things like that,” Simon said. “It's not so much what you have growing in your yard or the neighbor's yard, these things are really coming from canyons.”
The report measured a city's ranking through pollen scores, over-the-counter allergy medicine use, and availability of board-certified allergists/immunologists.
The San Diego-based allergists said antihistamines, nasal sprays and sinus rinses with saline water can help treat allergy symptoms. For more serious cases, they said, contact an allergist.
One particularly bad pollen season doesn't necessarily mean it will be the new standard. But Simon said the shift in pollen count may be a continuing trend due to long term effects from climate change.
