Altdorf pollen forecast - today, tomorrow and the week ahead
Pollen Today
Today (20 September) pollen in Altdorf is low; grass is low.
Pollen Tomorrow
Tomorrow (21 September 2026) grass no longer expected.
7-Day Trend
Over the next week grass will increase; cypress, willow, and mugwort 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) | Low | 13/100 |
| Willow (Salicaceae) | None | 0/100 |
| Mugwort (Artemisia) | None | 0/100 |
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) | None | 0/100 |
Local Environmental Conditions
Altdorf's Reuss valley setting beneath the Uri Alps features spruce, ash, and alpine meadow grasses as pollen sources, with exposure varying between forested mountain slopes and the historic Tell-legend town centre.
Altdorf sees its pollen season start in January with hazel and alder, birch peaking through April, oak and chestnut close behind, and grass finally taking over across June and July. Wooded foothills and farmland here contribute a steady supply, while the lake basin's shape can trap pollen under calm, still air.
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Resource Hub
Pollen forecast neighborhoods 2 neighborhoods
Sports venues in Altdorf 1 sports venue
Frequently Asked Questions About Pollen in Uri
Is pollen high in Altdorf right now?
On 20 September 2026, overall pollen levels in Altdorf are low. Grass is the main contributor to airborne pollen
Will pollen levels change in Altdorf tomorrow?
On 21 September 2026, pollen conditions in Altdorf will be similar to today with no significant pollen expected.
Is pollen expected to decrease in Altdorf this week?
According to the five-day outlook, grass pollen levels will increase later in the week.
Which pollen types are currently active in Altdorf?
On 20 September 2026, Grass is the dominant pollen source in Altdorf. artemisia, cypress, and willow are not currently active.
When is pollen season in Altdorf?
How often is the Altdorf pollen forecast updated?
The Altdorf pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Altdorf 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 Altdorf 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 Altdorf, 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).
