Weymouth pollen forecast - today, tomorrow and the week ahead
Pollen Today
Today (20 September) pollen in Weymouth is moderate; ragweed is moderate; grass and mugwort are low.
Pollen Tomorrow
Tomorrow (21 September 2026) mugwort remains low, grass increasing, ragweed increasing.
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) | Low | 18/100 |
| Willow (Salicaceae) | None | 0/100 |
| Mugwort (Artemisia) | Low | 1/100 |
| Ragweed (Ambrosia) | Moderate | 39/100 |
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 | 30/100 | |
| Willow (Salicaceae) | None | 0/100 | — |
| Mugwort (Artemisia) | Low | 13/100 | |
| Ragweed (Ambrosia) | High | 51/100 |
Local Environmental Conditions
Weymouth's Norfolk County Massachusetts Boston suburban setting features oak, maple, and birch as the main tree pollen sources, with exposure varying between the wooded residential areas and the more built-up commercial corridors along Route 18. The Weymouth Back River estuary creates distinct coastal-inland pollen gradients, while the Great Esker Park and Whitman's Pond corridor provide locally significant green space and the coastal setting provides periodic marine influence on pollen dispersal throughout the season.
Weymouth's Boston suburban setting in Massachusetts produces a season opening in late March with elm and maple before birch and oak peak through May. Grass from surrounding New England land peaks through June and July before mugwort and nettle extend exposure into September. The Weymouth Back River coastal setting moderates temperatures, while the Boston metropolitan urban heat island extends the season slightly throughout.
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Resource Hub
Pollen forecast neighborhoods 3 neighborhoods
Sports venues in Weymouth 1 sports venue
Frequently Asked Questions About Pollen in Massachusetts
Is pollen high in Weymouth right now?
On 20 September 2026, overall pollen levels in Weymouth are moderate. Ambrosia is the main contributor to airborne pollen, while grass and artemisia remain at lower levels
Will pollen levels change in Weymouth tomorrow?
On 21 September 2026, pollen conditions in Weymouth will be different from today, with artemisia at low levels and grass, ambrosia increasing
Is pollen expected to decrease in Weymouth this week?
According to the five-day outlook, grass, ambrosia, and artemisia pollen levels are expected to gradually decrease, suggesting improving conditions later in the week.
Which pollen types are currently active in Weymouth?
On 20 September 2026, Ambrosia is the dominant pollen source in Weymouth. grass and artemisia are also present but at lower levels.
When is pollen season in Weymouth?
How often is the Weymouth pollen forecast updated?
The Weymouth pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Weymouth 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 Weymouth 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 Weymouth, 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).
