Chadds Ford pollen forecast - today, tomorrow and the week ahead
Pollen Today
Today (20 September) pollen in Chadds Ford is moderate; grass and ragweed are moderate; mugwort is low.
Pollen Tomorrow
Tomorrow (21 September 2026) grass declining, ragweed declining, mugwort no longer expected.
7-Day Trend
Over the next week grass, mugwort, and ragweed will increase.
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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) | Moderate | 50/100 |
| Willow (Salicaceae) | None | 0/100 |
| Mugwort (Artemisia) | Low | 17/100 |
| Ragweed (Ambrosia) | Moderate | 49/100 |
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 | 19/100 | |
| Willow (Salicaceae) | None | 0/100 | — |
| Mugwort (Artemisia) | None | 0/100 | |
| Ragweed (Ambrosia) | Low | 16/100 |
Local Environmental Conditions
Chadds Ford sits on the rolling Brandywine Valley, where the dominant vegetation is a mix of oak and tulip poplar forest, dogwood understory, and farmland hedgerows, shaping the local pollen profile across the seasons. Exposure varies with proximity to green space versus the more built-up parts of Chadds Ford. Residents who spend time outdoors around Chadds Ford typically notice the shift as each season turns over.
In Chadds Ford, pollen season begins with cedar and elm starting in late February with oak following close behind through April. Grass follows, peaking through May and June, while ragweed and mugwort extend the weed season into September. Relatively mild winters here bring the tree pollen season forward compared to points further north, shaping conditions across the city.
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Frequently Asked Questions About Pollen in Pennsylvania
Is pollen high in Chadds Ford right now?
On 20 September 2026, overall pollen levels in Chadds Ford are moderate. Ambrosia is the main contributor to airborne pollen, while grass and artemisia remain at lower levels
Will pollen levels change in Chadds Ford tomorrow?
On 21 September 2026, pollen conditions in Chadds Ford will be different from today, with ambrosia, grass continuing to decline
Is pollen expected to decrease in Chadds Ford this week?
According to the five-day outlook, ambrosia, artemisia, and grass pollen levels will increase later in the week.
Which pollen types are currently active in Chadds Ford?
On 20 September 2026, Ambrosia is the dominant pollen source in Chadds Ford. grass and artemisia are also present but at lower levels.
When is pollen season in Chadds Ford?
How often is the Chadds Ford pollen forecast updated?
The Chadds Ford pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Chadds Ford 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 Chadds Ford 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 Chadds Ford, 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).
