Dennis pollen forecast - today, tomorrow and the week ahead
Pollen Today
Today (20 September) pollen in Dennis is high; ragweed is high; grass and mugwort are low.
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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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 | 25/100 |
| Willow (Salicaceae) | None | 0/100 |
| Mugwort (Artemisia) | Low | 17/100 |
| Ragweed (Ambrosia) | High | 59/100 |
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 | 25/100 | |
| Willow (Salicaceae) | None | 0/100 | — |
| Mugwort (Artemisia) | Low | 17/100 | |
| Ragweed (Ambrosia) | High | 58/100 |
Local Environmental Conditions
Around Dennis, here, just around the area, hazel and willow thrive along the damp bank, both prolific early wind-pollinators. Woodland where oak stands alongside birch, the latter especially aggressive as an allergen, not far from here. Small shifts in elevation or soil type can move these figures a little either way.
For Dennis, water-edge hazel and willow are usually the first allergenic trees active here, climbing steadily from late winter into March. Woodland oak and birch pick up the pace next, through mid-to-late spring, building to its sharpest point across April and May. Grass pollen becomes the dominant allergen through late spring, peaking in June, then yields to ragweed, the dominant late-summer and fall allergen through October.
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Resource Hub
Pollen forecast neighborhoods 5 neighborhoods
Sports venues in Dennis 2 sports venues
Frequently Asked Questions About Pollen in Massachusetts
Is pollen high in Dennis right now?
On 20 September 2026, overall pollen levels in Dennis are high. Ambrosia is the main contributor to airborne pollen, while artemisia and grass remain at lower levels
Will pollen levels change in Dennis tomorrow?
On 21 September 2026, pollen conditions in Dennis will be similar to today, with ambrosia at high levels, artemisia at low levels, grass at low levels
Is pollen expected to decrease in Dennis 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 Dennis?
On 20 September 2026, Ambrosia is the dominant pollen source in Dennis. artemisia and grass are also present but at lower levels.
When is pollen season in Dennis?
How often is the Dennis pollen forecast updated?
The Dennis pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Dennis 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 Dennis 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 Dennis, 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).
