Experts are predicting a difficult Western Washington allergy season. Here’s why
We might be sneezing more in Bellingham and the rest of Western Washington this spring, thanks to a wet rainy season, meteorologists at AccuWeather said in their annual allergy forecast.
Tree pollen is expected to start filling the air earlier than normal and will remain above normal levels for several weeks, AccuWeather’s senior meteorologist Alan Reppert said. Dramatically high levels are possible in Portland and Seattle, and Northwest residents could be feeling those effects soon.
“The main reason we are honing in on things being pretty bad with tree pollen is due to a bit earlier start to the pollen season than we typically see, and also more rainfall that we are looking at in the early part of the season that will aid in trees kicking off their growth quicker and stronger than most seasons. So despite seeing some increased rainfall to wash the pollen out of the air, we will still see more growth from the trees and quicker growth from the trees before the pollen season comes to an end,” Reppert told The Herald in an email.
Early blooming trees, such as juniper and bigleaf maple, start to produce buds or catkins between February and April, before their leaves appear, he said.
Other kinds of maple and pine trees bloom later in the spring. “Grass pollen is typically our summer pollen, and weed pollen typically is more late summer and fall. Both of those seasons look to be low over the (Pacific Northwest),” Reppert said.
Temperature, seasonal rainfall, wind and spring frosts can influence how much pollen ends up in the air.
Despite a January dry spell, rainfall as measured at Bellingham International Airport is far above normal so far in the 2025-2026 water year, which starts Oct. 1.
Observed rainfall from Oct. 1 to Feb. 28 was 25.6 inches, against normal rainfall for the period of 20.72 inches.
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