OR · Allergy Season Guide
Hillsboro Allergy Season Guide
PollyMap is actively seeking a qualified local collection partner in Hillsboro. This guide uses regional climate and historical allergen data while we recruit a local host.
PollyMap is actively looking for a qualified local partner in Hillsboro.
We're recruiting a qualified local allergy clinic — or any clinic that provides allergy care — to become the official pollen collection partner for Hillsboro.
Become the Official PollyMap Partner for HillsboroPollyMap allergy partner near Hillsboro
The closest active PollyMap allergy partner is within 75 miles of Hillsboro.
Summary
PollyMap does not yet have weekly collected pollen data for Hillsboro. This guide is based on regional climate patterns and historical allergen data while we recruit a local collection partner. Tree pollen peaks in spring, grass pollen in late spring and early summer, and weed pollen in late summer and fall.
Local allergy guide for Hillsboro
Hillsboro shares Oregon's a cool, wet maritime climate with mild summers, rainy winters, and high year-round humidity. at 194 ft elevation.
Hillsboro at 194 ft elevation sits within Oregon's broader regional climate.
In Hillsboro, 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.
Hillsboro's local mold profile includes Cladosporium, Alternaria, Penicillium. Spore counts tend to peak after rainfall and during the warm, humid portion of the year.
Local weather — temperature, rainfall, wind, and humidity — drives day-to-day pollen levels. Dry, windy days following warm weather typically produce the highest counts, while heavy rain temporarily clears the air.
Hillsboro monthly allergy calendar
Typical month-by-month intensity for the four major airborne allergen categories in Hillsboro.
| 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 |
Most common airborne molds
Frequently asked questions about allergies in Hillsboro
Related guides
State Guide
Oregon Allergy Season Guide
Nearby city
Portland Allergy Season Guide
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Eugene Allergy Season Guide
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Salem Allergy Season Guide
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Gresham Allergy Season Guide
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Bend Allergy Season Guide
Library
Pollen species library
Library
Mold species library
Reports
Latest PollyMap reports
Partners
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