Williamstown pollen forecast — Stoney Ledge Group Site neighborhood
Pollen Today
Today (20 September) pollen in Stoney Ledge Group Site, Williamstown 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, 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) | None | 0/100 |
| Willow (Salicaceae) | None | 0/100 |
| Mugwort (Artemisia) | None | 0/100 |
| Ragweed (Ambrosia) | Low | 10/100 |
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 | 13/100 | |
| Willow (Salicaceae) | None | 0/100 | — |
| Mugwort (Artemisia) | Low | 8/100 | |
| Ragweed (Ambrosia) | Moderate | 26/100 |
Local Environmental Conditions
Around Stoney Ledge Group Site, hazel and willow grow along the bank, contributing some of the season's earliest allergenic pollen, near this part of town. Located in the vicinity, this area has this patch of forest is largely oak and birch, a pairing known for heavy spring pollen output. As with most local readings, actual levels can vary somewhat with short-term weather swings.
In Stoney Ledge Group Site, the woodland's oak and birch trees become the main pollen source by mid-spring, peaking in the heart of spring, generally April into May. By late spring, grass pollen is climbing steadily toward a June high point, before ragweed pollen takes center stage across mid-August into October.
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Resource Hub
Pollen forecast neighborhoods 4 neighborhoods
Sports venues in Williamstown 2 sports venues
Frequently Asked Questions About Pollen in Massachusetts
Is pollen high in Williamstown right now?
On 20 September 2026, overall pollen levels in Williamstown are low. Ambrosia is the main contributor to airborne pollen
Will pollen levels change in Williamstown tomorrow?
On 21 September 2026, pollen conditions in Williamstown will be different from today, with artemisia at low levels, grass at low levels and ambrosia increasing
Is pollen expected to decrease in Williamstown 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 Williamstown?
On 20 September 2026, Ambrosia is the dominant pollen source in Williamstown. artemisia and grass are not currently active.
When is pollen season in Williamstown?
How often is the Williamstown pollen forecast updated?
The Williamstown pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Williamstown 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 Williamstown 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 Williamstown, 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).
