Tredyffrin Township pollen forecast — Howellville neighborhood
Pollen Today
Today (20 September) pollen in Howellville, Tredyffrin Township 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 | 41/100 |
| Willow (Salicaceae) | None | 0/100 |
| Mugwort (Artemisia) | Low | 10/100 |
| Ragweed (Ambrosia) | Moderate | 47/100 |
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 | 13/100 | |
| Willow (Salicaceae) | None | 0/100 | — |
| Mugwort (Artemisia) | None | 0/100 | |
| Ragweed (Ambrosia) | Low | 17/100 |
Local Environmental Conditions
Hazel and willow grow along the bank, contributing some of the season's earliest allergenic pollen; this sits within the neighborhood's edge. Located within the neighborhood's edge, this area has woods composed largely of oak and birch, a combination tied to sharp spring pollen spikes. This area, within the neighborhood's edge, has a park combining lawn grass and planted trees, both minor but real contributors to pollen here.
The waterside hazel and willow are consistently first to release pollen each year, usually peaking sometime between late winter and the end of March. The woodland's oak and birch trees become the main pollen source by mid-spring, reaching maximum intensity across the April-May window. Moving into early summer, grass pollen climbs to its seasonal high in June, with ragweed climbing to its own high point from mid-August through October.
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Pollen forecast neighborhoods 3 neighborhoods
Frequently Asked Questions About Pollen in Pennsylvania
Is pollen high in Tredyffrin Township right now?
On 20 September 2026, overall pollen levels in Tredyffrin Township are moderate. Ambrosia is the main contributor to airborne pollen, while grass and artemisia remain at lower levels
Will pollen levels change in Tredyffrin Township tomorrow?
On 21 September 2026, pollen conditions in Tredyffrin Township will be different from today, with ambrosia, grass continuing to decline
Is pollen expected to decrease in Tredyffrin Township 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 Tredyffrin Township?
On 20 September 2026, Ambrosia is the dominant pollen source in Tredyffrin Township. grass and artemisia are also present but at lower levels.
When is pollen season in Tredyffrin Township?
How often is the Tredyffrin Township pollen forecast updated?
The Tredyffrin Township pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Tredyffrin Township 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 Tredyffrin Township 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 Tredyffrin Township, 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. |
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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).
