Leiden pollen forecast - today, tomorrow and the week ahead

On 16 July 2026, overall pollen levels in Leiden are low. Grass is the main contributor to airborne pollen

On 17 July 2026, pollen conditions in Leiden will be similar to today, with grass at low levels

According to the five-day outlook, cypress, grass, and artemisia pollen levels will increase later in the week.

On 16 July 2026, Grass is the dominant pollen source in Leiden. hazel, cypress, willow, alder, artemisia, and birch are not currently active.

Leiden'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 Old Rhine and Nieuwe Rijn river corridors channel airflows, while surrounding South Holland farmland and the coastal dune landscape contribute substantial grass and tree pollen. The North Sea proximity means onshore westerly winds frequently disperse pollen.

The Leiden pollen forecast is updated four times daily. See the timestamp below for the most recent update.

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.

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.