Leiden Pollen Forecast - Today, Tomorrow and the Week Ahead
Pollen Today
Today (10 October) pollen in Leiden is low; mold (alternaria) and mold (cladosporium) are low.
Pollen Tomorrow
Tomorrow (11 October 2026) levels are similar to today.
7-Day Trend
Over the next week mugwort will increase; mold (alternaria) and mold (cladosporium) will decrease; cypress, grass, and willow will remain stable.
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Pollen Risk
Today - 10 October
| 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) | None | 0/100 |
| Mold (Alternaria) | Low | 4/100 |
| Mold (Cladosporium) | Low | 12/100 |
Tomorrow - 11 October
| 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 | |
| Mold (Alternaria) | Low | 4/100 | |
| Mold (Cladosporium) | Low | 13/100 |
Local Environmental Conditions
The area around the heart of Leiden is densely built up, with some woodland. Common allergenic trees nearby include oak, maple and alder. Grasses and weeds such as plantain and mugwort round out the local mix. Compared with most places, mugwort is especially widespread here, which makes it one of the key local allergens.
Alder opens the pollen season in late winter. Tree pollen peaks in late spring, when the weather warms to around 15°C and oak and maple are in full flower. Grass pollen follows, peaking in early summer and easing off by late summer. The most intense period comes from late spring into early fall, when plantain and mugwort are in flower.
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Frequently Asked Questions About Pollen in Zuid-Holland
Is pollen high in Leiden right now?
Currently, there is no significant pollen in Leiden.
Will pollen levels change in Leiden tomorrow?
On 11 October 2026, pollen conditions in Leiden will be similar to today with no significant pollen expected.
Is pollen expected to decrease in Leiden this week?
According to the five-day outlook, artemisia pollen levels will increase later in the week.
Which pollen types are currently active in Leiden?
On 10 October 2026, there are no significant pollen types in Leiden.
When is pollen season in Leiden?
How often is the Leiden pollen forecast updated?
The Leiden pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Leiden 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 Leiden 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 Leiden, 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 pollen scores represent risk levels, not direct pollen measurements. Higher scores indicate higher risk.
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).
