High ozone concentrations in the Netherlands - chance of smog
The National Institute for Public Health and the Environment (RIVM) has issued a warning for high levels of ozone in the Netherlands on Tuesday, 26 May 2026. The highest concentrations appear to be occurring in a band from Leiden towards Hilversum, Utrecht and Flevoland, reaching as far as Zwolle. Air quality in and near this band may be ‘poor’ due to smog from ozone.