Nashua pollen forecast - today, tomorrow and the week ahead
Pollen Today
Today (20 September) pollen in Nashua 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 | 15/100 |
| Willow (Salicaceae) | None | 0/100 |
| Mugwort (Artemisia) | None | 0/100 |
| Ragweed (Ambrosia) | Low | 25/100 |
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 | 55/100 | |
| Willow (Salicaceae) | None | 0/100 | — |
| Mugwort (Artemisia) | Low | 23/100 | |
| Ragweed (Ambrosia) | High | 65/100 |
Local Environmental Conditions
Nashua's parks, including Mine Falls Park and the Nashua River corridor, feature oak, birch, and maple as the main tree pollen sources, with exposure varying between these green areas and the more built-up city centre. Surrounding New Hampshire woodland and farmland contribute substantial tree and grass pollen, while the inland setting means rainfall is more frequent than on the coast, providing regular interruptions to exposure.
Nashua's pollen season opens with maple and birch from late March, slightly later than southern New England cities due to the cooler inland climate. Oak follows through April and May, with grass peaking through June and July. Ragweed extends the season into September. The Nashua River valley channels airflows, while surrounding New Hampshire woodland and farmland contribute substantial tree and grass pollen throughout the season.
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Resource Hub
Pollen forecast neighborhoods 1 neighborhood
Frequently Asked Questions About Pollen in New Hampshire
Is pollen high in Nashua right now?
On 20 September 2026, overall pollen levels in Nashua are low. Ambrosia is the main contributor to airborne pollen, while grass remain at lower levels
Will pollen levels change in Nashua tomorrow?
On 21 September 2026, pollen conditions in Nashua will be different from today, with artemisia at low levels and ambrosia, grass increasing
Is pollen expected to decrease in Nashua 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 Nashua?
On 20 September 2026, Ambrosia is the dominant pollen source in Nashua. grass are also present but at lower levels. artemisia are not currently active.
When is pollen season in Nashua?
How often is the Nashua pollen forecast updated?
The Nashua pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Nashua 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 Nashua 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 Nashua, 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).
