Brentford pollen forecast - today, tomorrow and the week ahead
Pollen Today
Today (20 September) pollen in Brentford 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 | 43/100 |
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 | 56/100 |
Local Environmental Conditions
Around Brentford, oak and plane are the dominant species behind local tree pollen, with counts higher near parks than in the centre. Fields and hedgerows just outside town push grass pollen counts up noticeably once the prevailing Atlantic airflow set in. This mix of urban and rural influence gives Brentford a fairly typical pollen pattern for the wider region.
Pollen season in Brentford really gets going with oak, followed not long after by plane. Oak pollen typically runs from April to May, while plane follows on from April to June. Grass then takes over from May right through September, peaking around June and July for most people. Useful to know if you tend to feel it every spring.
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Frequently Asked Questions About Pollen in Hounslow
Is pollen high in Brentford right now?
On 20 September 2026, overall pollen levels in Brentford are moderate. Artemisia is the main contributor to airborne pollen
Will pollen levels change in Brentford tomorrow?
On 21 September 2026, pollen conditions in Brentford will be different from today, with artemisia increasing
Is pollen expected to decrease in Brentford this week?
According to the five-day outlook, artemisia pollen levels will increase later in the week.
Which pollen types are currently active in Brentford?
On 20 September 2026, Artemisia is the dominant pollen source in Brentford. cypress, grass, and willow are not currently active.
When is pollen season in Brentford?
How often is the Brentford pollen forecast updated?
The Brentford pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Brentford 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 Brentford 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 Brentford, 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).
