Windsor pollen forecast - today, tomorrow and the week ahead
Pollen Today
Today (20 September) pollen in Windsor is moderate; mugwort is moderate.
Pollen Tomorrow
Tomorrow (21 September 2026) mugwort increasing.
7-Day Trend
Over the next week mugwort will increase; cypress, grass, and willow will remain stable.
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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) | Moderate | 38/100 |
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) | None | 0/100 | |
| Willow (Salicaceae) | None | 0/100 | |
| Mugwort (Artemisia) | High | 52/100 |
Local Environmental Conditions
Windsor's parks and green spaces feature plane and lime as the main tree pollen sources, with exposure varying between these greener areas and the more built-up town centre. Fields and hedgerows just outside town push grass pollen counts up noticeably once light prevailing breezes set in. This mix of urban and rural influence gives Windsor a fairly typical pollen pattern for the wider region.
Windsor's pollen year has two main tree culprits: plane first, lime close behind. Plane pollen typically runs from April to June, before lime takes over, usually May to July. Don't forget grass, either — it runs May to September and usually causes the most trouble in June and July. Not a bad idea to stock up on antihistamines before it all kicks off.
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Frequently Asked Questions About Pollen in Windsor and Maidenhead
Is pollen high in Windsor right now?
On 20 September 2026, overall pollen levels in Windsor are moderate. Artemisia is the main contributor to airborne pollen
Will pollen levels change in Windsor tomorrow?
On 21 September 2026, pollen conditions in Windsor will be different from today, with artemisia increasing
Is pollen expected to decrease in Windsor this week?
According to the five-day outlook, artemisia pollen levels will increase later in the week.
Which pollen types are currently active in Windsor?
On 20 September 2026, Artemisia is the dominant pollen source in Windsor. grass, willow, and cypress are not currently active.
When is pollen season in Windsor?
How often is the Windsor pollen forecast updated?
The Windsor pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Windsor 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 Windsor 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 Windsor, 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).
