May 15, 2023 - Health

Portland allergy season lengthens with climate change

Length of allergy season in Portland
Data: Climate Central; Chart: Axios Visuals

The Pacific Northwest's temperate climate usually means allergy season arrives here earlier than the rest of the country. Not this year. Due to ample rain and late-season freezing temperatures, things are kicking into high gear right about now.

Why it matters: Allergy season in Portland increased by 26 days on average between 1970 and 2021, per an analysis from Climate Central, a nonprofit climate news organization, Alex Fitzpatrick and Alice Feng report.

  • That's based on the number of days between the last freeze each spring and the first freeze each fall — the annual window during which seasonal allergy sufferers are most likely to rely on their antihistamine of choice to get by each day.

Of note: Even if the sun makes a brief appearance, it quickly prompts evergreen trees — like cedars, junipers and firs— and grasses to start their annual reproductive ritual and release pollen.

  • Because this spring has been especially wet and dreary, allergy season was delayed. But since warmer weather has arrived, pollen readings spiked significantly in the last few weeks, according to Emily Trevillyan, a nurse at Portland's Allergy Clinic.

What they're saying: "Freezing halts the pollination process, so when we have a late freeze, there's a bit of a break for allergy sufferers, but then it just restarts again," Trevillyan told Axios.

The big picture: Allergy season increased by 15 days on average between 1970 and 2021 across about 200 U.S. cities.

Driving the news: The lengthening allergy season is tied to climate change, per Climate Central, with big health ramifications for the roughly one-quarter of Americans who suffer from seasonal allergies — and for respiratory health more broadly.

The bottom line: Ongoing climate change means further deviation from what was once considered the norm. If you feel like seasonal allergies are suddenly a bigger part of your life, there's solid data to back it up.

Be smart: Trevillyan recommends allergy sufferers start their over-the-counter medications before symptoms emerge, and to consider rinsing their eyes and face, or showering, after being outside for long periods of time.

  • Even when it's nice out, if you're prone to itchy eyes, keep those windows closed and, if you have one, turn your air conditioner on instead.

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