Seaside, Oregon pollen forecast - today, tomorrow and the week ahead
Pollen Today
Today (20 September) pollen in Seaside, Oregon is high; ragweed is high; grass and mugwort are low.
Pollen Tomorrow
Tomorrow (21 September 2026) mugwort remains low, ragweed remains high, grass no longer expected.
7-Day Trend
Over the next week grass will increase; mugwort and ragweed will decrease.
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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 | 1/100 |
| Willow (Salicaceae) | None | 0/100 |
| Mugwort (Artemisia) | Low | 14/100 |
| Ragweed (Ambrosia) | High | 57/100 |
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) | None | 0/100 | |
| Willow (Salicaceae) | None | 0/100 | — |
| Mugwort (Artemisia) | Low | 12/100 | |
| Ragweed (Ambrosia) | High | 55/100 |
Local Environmental Conditions
Seaside's setting on a coastal resort town at the mouth of the Necanicum River supports coastal Sitka spruce forest, dune grasses, and riverside willow as the leading local vegetation, all factoring into the pollen count through the year. Wind patterns across the area help determine how far pollen travels from these source plants. Microclimates within the area can shift the timing slightly from one neighborhood to the next.
In Seaside, pollen season begins with alder and birch starting in February before maple peaks during March and April. A grass pollen peak follows through May and June; dock and mugwort keep weed pollen elevated into September. The mild, wet Pacific Northwest climate and frequent spring rain periodically wash pollen from the air, shaping conditions across the city.
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Frequently Asked Questions About Pollen in Oregon
Is pollen high in Seaside, Oregon right now?
On 20 September 2026, overall pollen levels in Seaside, Oregon are high. Ambrosia is the main contributor to airborne pollen, while artemisia and grass remain at lower levels
Will pollen levels change in Seaside, Oregon tomorrow?
On 21 September 2026, pollen conditions in Seaside, Oregon will be different from today, with ambrosia at high levels, artemisia at low levels
Is pollen expected to decrease in Seaside, Oregon this week?
According to the five-day outlook, ambrosia and artemisia pollen levels are expected to gradually decrease, while grass pollen will increase, suggesting mixed conditions later in the week.
Which pollen types are currently active in Seaside, Oregon?
On 20 September 2026, Ambrosia is the dominant pollen source in Seaside, Oregon. artemisia and grass are also present but at lower levels.
When is pollen season in Seaside, Oregon?
How often is the Seaside, Oregon pollen forecast updated?
The Seaside, Oregon pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Seaside, Oregon 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 Seaside, Oregon 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 Seaside, Oregon, 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).
