Lower Merion Township pollen forecast - today, tomorrow and the week ahead
Pollen Today
Today (20 September) pollen in Lower Merion 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 | 39/100 |
| Willow (Salicaceae) | None | 0/100 |
| Mugwort (Artemisia) | Low | 7/100 |
| 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 | 14/100 | |
| Willow (Salicaceae) | None | 0/100 | — |
| Mugwort (Artemisia) | None | 0/100 | |
| Ragweed (Ambrosia) | Low | 20/100 |
Local Environmental Conditions
Here, just around the area, the riverbank shelters hazel and willow, two trees whose pollen travels readily on the breeze. This area, close by, has oak and birch trees, with birch pollen especially potent during its brief spring window. This area, in the surrounding area, has the park's turf and planted trees form a small but steady source of grass and ragweed pollen.
Near the bank, hazel and willow lead the seasonal calendar, arriving ahead of the rest of the season, cresting around late winter. Oak and birch in the woods pick up where the earlier species leave off, usually hitting its highest point sometime between mid-April and mid-May. Moving into early summer, grass pollen climbs to its seasonal high in June, and ragweed later takes the lead from mid-August through October.
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Resource Hub
Pollen forecast neighborhoods 16 neighborhoods
Sports venues in Lower Merion Township 1 sports venue
Frequently Asked Questions About Pollen in Pennsylvania
Is pollen high in Lower Merion Township right now?
On 20 September 2026, overall pollen levels in Lower Merion Township are moderate. Grass is the main contributor to airborne pollen, while ambrosia and artemisia remain at lower levels
Will pollen levels change in Lower Merion Township tomorrow?
On 21 September 2026, pollen conditions in Lower Merion Township will be different from today, with grass, ambrosia continuing to decline
Is pollen expected to decrease in Lower Merion Township this week?
According to the five-day outlook, artemisia, grass, and ambrosia pollen levels will increase later in the week.
Which pollen types are currently active in Lower Merion Township?
On 20 September 2026, Grass is the dominant pollen source in Lower Merion Township. ambrosia and artemisia are also present but at lower levels.
When is pollen season in Lower Merion Township?
How often is the Lower Merion Township pollen forecast updated?
The Lower Merion Township pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Lower Merion 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 Lower Merion 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 Lower Merion 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. |
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).
