Pendleton pollen forecast - today, tomorrow and the week ahead
Pollen Today
Today (20 September) pollen in Pendleton is high; grass and ragweed are high; mugwort is moderate.
Pollen Tomorrow
Tomorrow (21 September 2026) levels are similar to today.
7-Day Trend
Over the next week grass, mugwort, and ragweed will decrease.
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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) | High | 70/100 |
| Willow (Salicaceae) | None | 0/100 |
| Mugwort (Artemisia) | Moderate | 37/100 |
| Ragweed (Ambrosia) | High | 70/100 |
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) | High | 65/100 | |
| Willow (Salicaceae) | None | 0/100 | — |
| Mugwort (Artemisia) | Moderate | 29/100 | |
| Ragweed (Ambrosia) | High | 67/100 |
Local Environmental Conditions
Pendleton's setting on the wheat-farming plateau of the Columbia Basin supports wheat fields, cottonwood along the Umatilla River, and native prairie grasses as the leading local vegetation, all factoring into the pollen count through the year. None of this is unusual for a town with Pendleton's particular mix of terrain and plant life. Small local variations aside, this pattern holds fairly steady from year to year.
Pendleton's tree pollen season begins with alder and birch from February before maple takes over and peaks through March and April. Grass pollen builds through May and June, and plantain and nettle stretch the season into September. Frequent spring rain across the Pacific Northwest periodically clears pollen from the air, moderating peak counts, shaping conditions across the city.
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Frequently Asked Questions About Pollen in Oregon
Is pollen high in Pendleton right now?
On 20 September 2026, overall pollen levels in Pendleton are high. Ambrosia is the main contributor to airborne pollen, while grass and artemisia remain at lower levels
Will pollen levels change in Pendleton tomorrow?
On 21 September 2026, pollen conditions in Pendleton will be similar to today, with ambrosia at high levels, artemisia at moderate levels, grass at high levels
Is pollen expected to decrease in Pendleton this week?
According to the five-day outlook, ambrosia, artemisia, and grass pollen levels are expected to gradually decrease, suggesting improving conditions later in the week.
Which pollen types are currently active in Pendleton?
On 20 September 2026, Ambrosia is the dominant pollen source in Pendleton. grass and artemisia are also present but at lower levels.
When is pollen season in Pendleton?
How often is the Pendleton pollen forecast updated?
The Pendleton pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Pendleton 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 Pendleton 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 Pendleton, 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).
