Ozone concentration levels may well exceed the European information threshold (180 µg/m³) everywhere in Belgium on Wednesday and Thursday, according to the Belgian Interregional Environment Agency (IRCEL – CELINE). Due to tropical temperatures, maximum hourly concentration levels expected on Wednesday are likely to fall between 160 and 200 µg/m³. There is a significant risk levels will go over the threshold, especially in the north of the country. Locally, levels may go slightly over the alert threshold (240 µg/m³).
Ozone concentration levels will remain high on Thursday (between 120 and 220 µg/m³), with a high risk of exceeding the information threshold in locations which are sunny in the afternoon.
The hot weather will continue into Friday, with the likelihood of storms increasing as the day goes on. The risk of ozone levels exceeding the threshold will also be high on Friday.
When levels go over the European information threshold, vulnerable people are advised to avoid any strenuous activity and to stay indoors between noon and 10:00pm.