Haarlem pollen forecast - today, tomorrow and the week ahead
Pollen Today
Today (20 September) pollen in Haarlem is moderate; mugwort is moderate.
Pollen Tomorrow
Tomorrow (21 September 2026) levels are similar to today.
7-Day Trend
Over the next week grass and mugwort will increase; cypress and willow will remain stable.
Explore Forecasts
Air Quality
Pollen in Other Cities
Air Quality in Other Cities
Get More in Our App
Local pollen and air quality forecasts, interactive pollen maps and route profiles
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) | None | 0/100 |
| Willow (Salicaceae) | None | 0/100 |
| Mugwort (Artemisia) | Moderate | 39/100 |
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) | Moderate | 45/100 |
Local Environmental Conditions
Haarlem's parks and the Spaarne River corridor feature oak, birch, and linden as the main tree pollen sources, with exposure varying between green areas and the more built-up city centre. Surrounding North Holland farmland and the coastal dune landscape contribute substantial grass and tree pollen, while the North Sea coast position means onshore westerly winds can frequently disperse urban pollen.
Haarlem's pollen season runs from January through August, opening with hazel and alder from January before birch peaks through April. Oak and ash follow through April and May, with grass peaking through June and July. The North Sea coast position means onshore westerly winds frequently disperse pollen, while surrounding North Holland farmland and the coastal dune landscape contribute substantial grass and tree pollen throughout the season.
Get pollen & AQ on Strava
Follow your environmental exposure and performance with the free Airmine-Strava integration. See your pollen and air quality exposure for every Strava activity.
Resource Hub
Frequently Asked Questions About Pollen in Noord-Holland
Is pollen high in Haarlem right now?
On 20 September 2026, overall pollen levels in Haarlem are moderate. Artemisia is the main contributor to airborne pollen
Will pollen levels change in Haarlem tomorrow?
On 21 September 2026, pollen conditions in Haarlem will be similar to today, with artemisia at moderate levels
Is pollen expected to decrease in Haarlem this week?
According to the five-day outlook, artemisia and grass pollen levels will increase later in the week.
Which pollen types are currently active in Haarlem?
On 20 September 2026, Artemisia is the dominant pollen source in Haarlem. willow, cypress, and grass are not currently active.
When is pollen season in Haarlem?
How often is the Haarlem pollen forecast updated?
The Haarlem pollen forecast is updated four times daily. See the timestamp below for the most recent update.
Does pollen in Haarlem 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 Haarlem 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 Haarlem, 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).
