Downtown Lewiston pollen forecast - today, tomorrow and the week ahead
Pollen Today
Today (20 September) pollen in Downtown Lewiston is moderate; ragweed is moderate.
Pollen Tomorrow
Tomorrow (21 September 2026) ragweed increasing, grass at moderate levels, 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) | None | 0/100 |
| Willow (Salicaceae) | None | 0/100 |
| Mugwort (Artemisia) | None | 0/100 |
| Ragweed (Ambrosia) | Moderate | 28/100 |
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 | 26/100 | |
| Willow (Salicaceae) | None | 0/100 | — |
| Mugwort (Artemisia) | Low | 16/100 | |
| Ragweed (Ambrosia) | High | 56/100 |
Local Environmental Conditions
Given its setting — the city's historic mill-town downtown along the Androscoggin River — Downtown Lewiston's pollen exposure lines up with the broader Lewiston pattern rather than diverging from it. As with most sublevel sites, local landscaping can shift counts slightly from the citywide average.
Downtown Lewiston tracks Lewiston's broader pollen pattern, with maple and elm appearing from March before birch and oak peaks during April and May. Grass pollen rises through June and July, and a modest weed pollen tail continues into September. Cold winters give way to a fast, concentrated spring pollen ramp-up across the region, which shapes conditions at Downtown Lewiston much as it does elsewhere in Lewiston.
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Frequently Asked Questions About Pollen in Maine
Is pollen high in Downtown Lewiston right now?
On 20 September 2026, overall pollen levels in Downtown Lewiston are moderate. Ambrosia is the main contributor to airborne pollen
Will pollen levels change in Downtown Lewiston tomorrow?
On 21 September 2026, pollen conditions in Downtown Lewiston will be different from today, with artemisia at low levels, grass at moderate levels and ambrosia increasing
Is pollen expected to decrease in Downtown Lewiston this week?
According to the five-day outlook, artemisia, grass, and ambrosia pollen levels are expected to gradually decrease, suggesting improving conditions later in the week.
Which pollen types are currently active in Downtown Lewiston?
On 20 September 2026, Ambrosia is the dominant pollen source in Downtown Lewiston. artemisia and grass are not currently active.
When is pollen season in Downtown Lewiston?
How often is the Downtown Lewiston pollen forecast updated?
The Downtown Lewiston pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Downtown Lewiston 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 Downtown Lewiston 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 Downtown Lewiston, 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).
