Early Spring Triggers Rise in Allergy Symptoms Across the Netherlands
Unseasonably warm temperatures are prompting an early start to pollen season, causing an increase in allergy symptoms for many in the Netherlands. While the true arrival of spring is still to come, the mild weather is already stimulating plant growth and pollen release, with experts warning of a potential peak in complaints.
Hazels and alders are currently releasing significant amounts of pollen, impacting an estimated 700,000 people, according to bioloog Maurice Martens of Flora van Nederland, who updated information on February 26, 2026. Although rainfall can temporarily clear the air, dry and windy conditions allow pollen to spread, particularly as katkins develop.
The Hooikoortsradar provides up-to-date information on pollen forecasts, plants, and pollen types. The current pollen forecast indicates low levels of tree, grass, and weed pollen across the country, but the situation is evolving rapidly with the warmer weather. You can find more detailed information at Pollennieuws.nl.
The rise in pollen levels is coinciding with an unusually active period for butterflies, with February 26, 2026, being described as a “geweldige vlinderdag” (great butterfly day) by Nature Today. This early activity across the natural world underscores the impact of the warmer winter temperatures.
Data from the Nivel institute, which collects weekly data on health problems reported by doctors, shows that allergy-related visits to doctors are currently low but are expected to increase as pollen levels rise. The Nivel surveillance data, approved under governance code NZR-00317.010, shows a clear distinction between allergy symptoms and those of the flu or common cold. More information on Nivel’s surveillance can be found here.
For those suffering from hay fever, staying informed about pollen levels and taking preventative measures is crucial. The hooikoortsradar allows users to check pollen forecasts for specific locations and identify potential triggers. This early start to the pollen season highlights the importance of being prepared for a potentially challenging allergy season.
