The Interregional Environment Cell (CELINE) issued a warning about high ozone concentrations on Wednesday, confirmed by the Royal Meteorological Institute as the hottest day of the year so far.
At the warmest part of the day, temperatures in the Brussels commune of Uccle rose to 29.5°C, according to IRM meteorologist David Dehenauw. Elsewhere in the country, the mercury even hit 30°.
The official measurement was taken at Uccle weather station, which recorded Wednesday’s high of 29.5 degrees. This makes it the warmest day of the year to date. The ultraviolet index also reached 6.
Due to the heat, air pollution and sunlight, ozone concentrations exceeded the European information threshold of 180 µg/m3 – the mass of particles per unit volume of air - prompting CELINE to issue the warning.
The ozone peak occurred during the afternoon: at around 4 p.m., readings of 207 µg/m3 and 194 µg/m3 were measured in Ghent and the East Flanders commune of Destelbergen, respectively.
