WA · Allergy Season Guide
Washington Allergy Season Guide
Washington experiences a cool, wet maritime climate with mild summers, rainy winters, and high year-round humidity.
Summary
Washington has 0 active PollyMap collection sites, and is seeking partners in 5 additional cities. Tree pollen typically dominates early spring, grass pollen peaks in late spring and early summer, and weed pollen (including ragweed) extends from late summer through fall.
PollyMap collection status across Washington
Statewide allergy overview
Washington experiences a cool, wet maritime climate with mild summers, rainy winters, and high year-round humidity.
Alder, birch, and cedar lead a strong late-winter and early-spring tree season. Grass pollen is intense from May through July, and the Willamette and Puget lowlands are among the heaviest grass pollen regions in North America.
Persistent rain and overcast skies produce some of the highest mold spore counts in the country, especially Cladosporium and Alternaria from fall through spring.
Allergy patterns vary by elevation and proximity to coast or mountains within Washington, but most of the state shares a common seasonal rhythm of spring tree pollen, summer grass pollen, and late-summer to fall weed pollen.
Washington allergy calendar
Month-by-month intensity for the four major airborne allergen categories.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Tree | High | V.High | V.High | High | Mod | Low | Low | Low | Low | Low | Mod | Mod |
| Grass | — | Low | Mod | High | V.High | V.High | High | Mod | Low | Low | Low | — |
| Weed | Low | Low | Mod | Mod | Mod | Mod | High | High | High | Mod | Low | Low |
| Mold | High | High | Mod | Mod | Low | Low | Low | Mod | Mod | High | V.High | High |
Top airborne molds
Major city guides in Washington
Latest PollyMap reports for Washington
Partner Program
Become a PollyMap Collection Partner in Washington
We work with allergy clinics, naturopathic clinics, universities, and qualified environmental health professionals to build the most reliable, locally-collected pollen network in America.
Partner benefits
- Dedicated local partner profile on PollyMap
- Local exposure to thousands of allergy searchers
- Backlinks from your city and state guide pages
- Lead generation from local allergy patients
- Featured on every local PollyMap report
- Recognition as a pollen data collection center
- Collaboration on local pollen research and reports
Partner requirements
- Receive a PollyKit weekly by mail
- Hang the PollyKit collector for 24–48 hours
- Mail the sample back weekly using prepaid packaging
- Maintain a consistent collection schedule year-round
Test the air at your address
Curious what's actually in the air at your Washington home or office?
The PollyKit is the easiest air-sampling kit on the market — collect outdoor pollen and airborne mold indoors at your home, office, classroom or rental, then mail it in for a full lab report. Just $39.99.
- Outdoor pollen counts
- Indoor airborne mold
- Lab-analyzed results
- Ships nationwide
What's in the box
- Air sampling rodsx2
- Indoor mold slidex1
- Prepaid lab returnincluded
- Personal results report3–5 days
The only consumer kit that pairs outdoor pollen with indoor airborne mold sampling.
Frequently asked questions
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