Willits pollen forecast - today, tomorrow and the week ahead
Pollen Today
Today (20 September) pollen in Willits is high; ragweed is high; grass and mugwort are 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) | Moderate | 32/100 |
| Willow (Salicaceae) | None | 0/100 |
| Mugwort (Artemisia) | Moderate | 30/100 |
| 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) | Moderate | 43/100 | |
| Willow (Salicaceae) | None | 0/100 | — |
| Mugwort (Artemisia) | Moderate | 42/100 | |
| Ragweed (Ambrosia) | High | 68/100 |
Local Environmental Conditions
The vegetation around Willits, on a mountain valley in Mendocino County's redwood country, is dominated by coast redwood groves and Douglas fir, with farmland grasses adding further seasonal pollen exposure. Counts here rise and fall with the same broad rhythm as other places sharing this setting. Nearby towns with similar terrain tend to see a broadly similar pattern.
Willits's pollen season opens with olive and acacia from January then eucalyptus follows, running through February. Grass pollen then peaks through March and April, and light weed pollen carries into September. Mild year-round temperatures push the pollen calendar earlier than in most of the country throughout the year.
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Pollen forecast neighborhoods 3 neighborhoods
Frequently Asked Questions About Pollen in California
Is pollen high in Willits right now?
On 20 September 2026, overall pollen levels in Willits are high. Ambrosia is the main contributor to airborne pollen, while artemisia and grass remain at lower levels
Will pollen levels change in Willits tomorrow?
On 21 September 2026, pollen conditions in Willits will be similar to today, with ambrosia at high levels, artemisia at moderate levels, grass at moderate levels
Is pollen expected to decrease in Willits 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 Willits?
On 20 September 2026, Ambrosia is the dominant pollen source in Willits. artemisia and grass are also present but at lower levels.
When is pollen season in Willits?
How often is the Willits pollen forecast updated?
The Willits pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Willits 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 Willits 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 Willits, 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).
