Williams pollen forecast - today, tomorrow and the week ahead
Pollen Today
Today (20 September) pollen in Williams is low; ragweed is low.
Pollen Tomorrow
Tomorrow (21 September 2026) ragweed increasing, grass at low levels, mugwort at low levels.
7-Day Trend
Over the next week grass and mugwort will increase; 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) | None | 0/100 |
| Willow (Salicaceae) | None | 0/100 |
| Mugwort (Artemisia) | None | 0/100 |
| Ragweed (Ambrosia) | Low | 11/100 |
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 | 1/100 | |
| Willow (Salicaceae) | None | 0/100 | — |
| Mugwort (Artemisia) | Low | 2/100 | |
| Ragweed (Ambrosia) | Moderate | 31/100 |
Local Environmental Conditions
For Williams, this area, close to this spot, has hazel and willow crowd the water's edge, both classic sources of early allergenic pollen. A green space of mown lawn and planted trees, both feeding into local grass and ragweed counts; this sits within easy reach. Comparable land cover in surrounding areas tends to produce a similar pollen mix overall.
At Williams, along the waterway, hazel and willow release pollen first, arriving ahead of the rest of the season, cresting around late winter. Grass pollen builds through late spring and peaks in June, then yields to ragweed, the dominant late-summer and fall allergen through October. Year-to-year timing varies a little, though the general sequence stays fairly consistent here.
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Pollen forecast neighborhoods 1 neighborhood
Frequently Asked Questions About Pollen in Minnesota
Is pollen high in Williams right now?
On 20 September 2026, overall pollen levels in Williams are low. Ambrosia is the main contributor to airborne pollen
Will pollen levels change in Williams tomorrow?
On 21 September 2026, pollen conditions in Williams will be different from today, with artemisia at low levels, grass at low levels and ambrosia increasing
Is pollen expected to decrease in Williams this week?
According to the five-day outlook, ambrosia pollen levels are expected to gradually decrease, while artemisia and grass pollen will increase, suggesting mixed conditions later in the week.
Which pollen types are currently active in Williams?
On 20 September 2026, Ambrosia is the dominant pollen source in Williams. artemisia and grass are not currently active.
When is pollen season in Williams?
How often is the Williams pollen forecast updated?
The Williams pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Williams 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 Williams 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 Williams, 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).
