Corvallis pollen forecast — Downtown Corvallis neighborhood
Pollen Today
Today (20 September) pollen in Downtown Corvallis, Corvallis is high; ragweed is high; grass and mugwort are low.
Pollen Tomorrow
Tomorrow (21 September 2026) grass remains low, mugwort remains low, ragweed declining.
7-Day Trend
Over the next week mugwort and ragweed will increase; grass will decrease.
Explore Forecasts
Air Quality & Mold
Pollen for Neighborhoods
Get More in Our App
Local pollen and air quality forecasts, interactive pollen maps and route profiles
Features and forecast availability vary by region.
Pollen Risk
Today - 20 September
| Pollen species | Level | Value |
|---|---|---|
| Alder (Alnus) | None | 0/100 |
| Birch (Betula) | None | 0/100 |
| Hazel (Corylus) | None | 0/100 |
| Cypress (Cupressaceae) | None | 0/100 |
| Grass (Poaceae) | Low | 20/100 |
| Willow (Salicaceae) | None | 0/100 |
| Mugwort (Artemisia) | Low | 15/100 |
| Ragweed (Ambrosia) | High | 56/100 |
Tomorrow - 21 September
| Pollen species | Level | Value | 7-Day Trend |
|---|---|---|---|
| Alder (Alnus) | None | 0/100 | — |
| Birch (Betula) | None | 0/100 | — |
| Hazel (Corylus) | None | 0/100 | — |
| Cypress (Cupressaceae) | None | 0/100 | — |
| Grass (Poaceae) | Low | 9/100 | |
| Willow (Salicaceae) | None | 0/100 | — |
| Mugwort (Artemisia) | Low | 4/100 | |
| Ragweed (Ambrosia) | Moderate | 45/100 |
Local Environmental Conditions
Downtown Corvallis is the city's compact downtown along the Willamette River. Vegetation here reflects the wider Corvallis area, with tree and grass pollen exposure following the same regional pattern as the rest of the city. Exposure here depends mainly on how much tree and lawn cover surrounds the immediate site.
As a neighborhood within Corvallis, Downtown Corvallis follows the same seasonal pollen curve, opening with alder and birch from February with maple joining in and continuing through March and April. Grass pollen builds through May and June, and mugwort and nettle extend exposure into September. The mild, wet Pacific Northwest climate and frequent spring rain periodically wash pollen from the air, a pattern felt across this part of Corvallis.
Get pollen & AQ on Strava
Follow your environmental exposure and performance with the free Airmine-Strava integration. See your pollen and air quality exposure for every Strava activity.
Resource Hub
Frequently Asked Questions About Pollen in Oregon
Is pollen high in Corvallis right now?
On 20 September 2026, overall pollen levels in Corvallis are high. Ambrosia is the main contributor to airborne pollen, while artemisia and grass remain at lower levels
Will pollen levels change in Corvallis tomorrow?
On 21 September 2026, pollen conditions in Corvallis will be different from today, with artemisia at low levels, grass at low levels and ambrosia continuing to decline
Is pollen expected to decrease in Corvallis this week?
According to the five-day outlook, grass pollen levels are expected to gradually decrease, while artemisia and ambrosia pollen will increase, suggesting mixed conditions later in the week.
Which pollen types are currently active in Corvallis?
On 20 September 2026, Ambrosia is the dominant pollen source in Corvallis. artemisia and grass are also present but at lower levels.
When is pollen season in Corvallis?
How often is the Corvallis pollen forecast updated?
The Corvallis pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Corvallis come from nearby or far away?
Studies show that most pollen exposure (often 70–90%) comes from nearby sources, such as local trees and vegetation. A good pollen forecast therefore depends on accurately representing local vegetation. Pollen can travel long distances, but this usually matters only early in the season or during specific wind events.
Are pollen levels in Corvallis based on measurements or forecasts?
Pollen data is often misunderstood. Most "pollen levels" are not real-time measurements, but forecasts.
Direct pollen measurements are typically delayed by 1-2 days because they require manual analysis. To show current conditions in Corvallis, modern forecasts combine recent measurements, weather data, and information about local vegetation.
This allows us to estimate pollen levels for today and the coming days, not just report the past.
Airmine’s atmospheric monitoring platform was developed with support from the European Space Agency (ESA)’s Business Applications and Space Solutions (BASS) team, using satellite and Earth observation technologies to improve emissions monitoring.
Understanding the Scale
The 0–100 scores represent risk levels, not direct measurements of pollen or air pollutant concentrations. Higher scores indicate higher risk. Pollen and air quality use different thresholds.
Pollen
| None | 0 | No or negligible risk of exposure. Pollen/mold exposure is expected to be minimal. |
| Low | 0-25 | Low risk of exposure. Small amounts of pollen or mold spores may be present. |
| Moderate | 25-50 | Moderate risk of exposure. Pollen/mold exposure is expected to be noticeable. |
| High | 50-75 | High risk of exposure. Elevated pollen/mold exposure is expected. |
| Very High | 75-100 | Very high risk of exposure. Pollen/mold exposure is expected to be at or near its highest levels. |
Get More in the Airmine Pollen app
Get 15-day pollen forecasts with morning, afternoon and evening detail, plus 5-day air quality forecasts. Explore interactive pollen risk maps, estimated pollen season start, route profiles and a symptoms diary.
Features and forecast availability vary by region. Currently covering Europe, the contiguous US, southern Canada, South Africa, Australia, Indonesia (Java & Bali), Brazil, Paraguay, Uruguay and the Buenos Aires area.
Developed with support from the European Space Agency (ESA) Business Applications and Space Solutions (BASS).
