Groton pollen forecast - today, tomorrow and the week ahead
Pollen Today
Today (20 September) pollen in Groton is low; grass and ragweed are low.
Pollen Tomorrow
Tomorrow (21 September 2026) grass increasing, ragweed increasing, mugwort at low levels.
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) | Low | 18/100 |
| Willow (Salicaceae) | None | 0/100 |
| Mugwort (Artemisia) | None | 0/100 |
| Ragweed (Ambrosia) | Low | 18/100 |
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) | High | 56/100 | |
| Willow (Salicaceae) | None | 0/100 | — |
| Mugwort (Artemisia) | Low | 25/100 | |
| Ragweed (Ambrosia) | High | 56/100 |
Local Environmental Conditions
At Groton, nearby, just outside the immediate area, hazel and willow grow along the bank, contributing some of the season's earliest allergenic pollen. Seasonal timing here generally tracks the wider region, give or take a week or so. Surrounding neighborhoods with similar tree cover typically see a closely comparable pollen mix.
In Groton, near the bank, hazel and willow lead the seasonal calendar, peaking in late winter through March. Grass pollen climbs toward a June peak, with ragweed climbing to its own high point from mid-August through October. This general pattern holds fairly steady across the surrounding county from year to year.
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Resource Hub
Pollen forecast neighborhoods 4 neighborhoods
Sports venues in Groton 1 sports venue
Frequently Asked Questions About Pollen in Massachusetts
Is pollen high in Groton right now?
On 20 September 2026, overall pollen levels in Groton are low. Ambrosia is the main contributor to airborne pollen, while grass remain at lower levels
Will pollen levels change in Groton tomorrow?
On 21 September 2026, pollen conditions in Groton will be different from today, with artemisia at low levels and ambrosia, grass increasing
Is pollen expected to decrease in Groton 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 Groton?
On 20 September 2026, Ambrosia is the dominant pollen source in Groton. grass are also present but at lower levels. artemisia are not currently active.
When is pollen season in Groton?
How often is the Groton pollen forecast updated?
The Groton pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Groton 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 Groton 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 Groton, 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).
