WA pollen report
Seattle Pollen Report
Seattle's lush, damp climate creates a pollen season that starts surprisingly early and stretches deep into summer. Western red cedar and alder begin pollinating in late winter — often before residents expect it — and the region's famous greenery means grass season is long, lush, and hard on allergy sufferers.
Collection coming soon to Seattle
PollyMap is actively recruiting a verified local partner in Seattle. Be the first to know — or apply to be the partner.
While we find a local clinic
Test the air at your own home in Seattle
No allergy clinic is reporting from Seattle yet. Until one does, you can order your own PollyKit — a simple air sampler you hang outdoors or indoors. Send it back and the PollyKit Lab shows you exactly what's floating in your air.
- Pollen from local trees, grasses and weeds
- Airborne mold spores
- Dust mites and other indoor allergens
Hang it outdoors
See which pollen and mold are in your yard this season.
Or hang it indoors
Check bedrooms and living spaces for mold, dust mites and more.
What drives allergies in Seattle
Trees: alder, cedar, and birch (February – May)
Red alder and western red cedar kick off Seattle's season in late winter, sometimes as early as February. Birch (Betula), bigleaf maple, and cottonwood follow through spring — birch is one of the region's most potent allergens.
Grasses: the long season (May – August)
The Pacific Northwest grows grass like nowhere else. Timothy, orchard grass, and ryegrass pollinate heavily from late spring well into summer — grass is the number one summer allergen in Seattle.
Weeds: a shorter fall (August – October)
Ragweed is less dominant here than in the Midwest, but nettle, plantain, and other weeds still fill the late-summer air until the fall rains return.
Mold: the rainy-season constant
Seattle's damp climate keeps outdoor mold spores (Alternaria, Cladosporium) present most of the year, with the highest counts in wet fall stretches and around decaying leaves.
Pollen patterns in Seattle
In Seattle, tree pollen — including Alder, Birch, Cedar — typically dominates from late winter through spring. Rye grass is the most common warm-season pollinator, and Plantain drives the largest fall pollen load.
Top trees
- Alder
- Birch
- Cedar
- Hazel
- Maple
Top grasses
- Rye
- Orchard
- Timothy
- Bentgrass
Top weeds
- Plantain
- Dock
- Nettle
Top molds
- Cladosporium
- Alternaria
- Penicillium
- Aspergillus
Seattle pollen calendar
Typical monthly intensity across the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| tree | ||||||||||||
| grass | ||||||||||||
| weed | ||||||||||||
| mold |
Historical reports
Cities near Seattle
Explore pollen activity in nearby cities reported by the PollyMap network.
Frequently asked questions
What is the pollen count in Seattle today?
PollyMap publishes real, measured pollen counts for Seattle — collected with physical samplers and identified under a microscope. The latest Seattle report on this page shows current tree, grass, weed, and mold levels.
Is the pollen count high in Seattle right now?
Seattle's pollen is highest from February through May (alder, cedar, birch) and again from May through August (grasses). Check the measured reports on this page for the latest levels.
When is allergy season in Seattle?
Longer than most people expect: tree pollen can start in February and grass season runs into August. Mold is present much of the year thanks to the damp climate.
Why are allergies bad in Seattle if it rains so much?
Rain briefly washes pollen out of the air, but Seattle's wet climate makes vegetation extraordinarily productive — and the dry, sunny stretches between storms can bring intense pollen surges.
Are you an allergy clinic in Seattle? Claim your territory on PollyMap.
PollyMap is a local authority-building tool for allergy clinics, ENT practices, and any clinic that offers allergy care. By becoming the Official PollyMap Partner for your part of Seattle, your clinic gets credited on real pollen reports, receives ready-to-share weekly content, and becomes the go-to local expert patients trust.
We assign each partner a designated territory within the Seattle metro — like a franchise territory. Seattle has room for multiple partners, but once your area is assigned, it's locked to your clinic.
No clinic has claimed a territory in Seattle yet. The best areas go to the first clinics that sign up — once one does, that part of town is off the table for everyone else.
The Puget Sound region has room for multiple PollyMap territories — from Bellevue and Redmond to Tacoma, Everett, and the Eastside suburbs. Claim yours to build clinic authority as the trusted local pollen source.
- Your clinic credited on every Seattle pollen report
- Weekly real-sample reports and ready-to-share content under your brand
- Locked territory — competing clinics can't claim your area
- Become the go-to allergy expert in your part of Seattle
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