Belgium extends yellow heat alert through Sunday as new heatwave could match June's 12-day duration
After a brief respite, Belgium faces a new heatwave with temperatures reaching 34°C. The IRM has extended its yellow warning through Sunday, and meteorologists warn the hot spell could last as long as the 12-day June heatwave.
Heatwave returns after brief respite
Barely a week after a record-breaking June heatwave that lasted twelve days and saw temperatures hit 39.9°C in Kleine-Brogel, Belgium is bracing for another prolonged hot spell. The Royal Meteorological Institute (IRM) forecasts a steady climb: Monday brought 28–30°C inland, Tuesday repeats those values, and by Wednesday the mercury reaches 31°C. Thursday and Friday push to 33°C and 32°C respectively, with the weekend staying above 30°C. In the Campine region, 34°C is possible.
- Mon 6 Jul
- 30 °C
- Tue 7 Jul
- 30 °C
- Wed 8 Jul
- 31 °C
- Thu 9 Jul
- 33 °C
- Fri 10 Jul
- 32 °C
- Sat 11 Jul
- 32 °C
- Sun 12 Jul
- 31 °C
Yellow alert extended to Sunday
The IRM initially issued a code yellow heat warning (level 2 of 4) through Thursday, then extended it to Friday, and on Wednesday prolonged it until midnight Saturday–Sunday for the entire country. Only the coast had remained under code green on Tuesday and Wednesday, but it too will switch to yellow on Thursday. The alert is tied to the ongoing activation of the federal heat and ozone peak plan.
We could experience a new heatwave, although it will be less intense than the previous one. Maximum temperatures expected next week will be around 32 degrees in the centre of the country. In the Campine region, they could reach 34 degrees.
Duration the main concern
Meteorologists are less alarmed by peak temperatures than by the episode's staying power. Pascal Mormal of the IRM noted that all models point to a long hot sequence, with thresholds likely exceeded from Thursday until at least the following Tuesday. Some reputable models keep temperatures above 30°C until Thursday or even Friday of the following week, raising the prospect of five to seven consecutive days above 30°C.
All the models are heading in the same direction. We are set for a relatively hot sequence. It's not extreme temperatures, but the duration of the episode seems worrying. Theoretically, we could exceed thresholds from Thursday until maybe Tuesday of next week.
Omega block drives the heat
The persistent heat is being driven by an omega block, a pattern in which the jet stream forms a large, stationary ridge resembling the Greek letter Ω. This traps a high-pressure anticyclone over the region, acting as a lid that compresses and heats the air below. The same configuration is pushing temperatures toward 40°C in France, Spain and Portugal, though Belgium remains on the northern fringe of the worst heat.
Health strain and warm nights
The SPF Santé Publique is maintaining its heat and ozone peak plan, urging extra hydration for the elderly and vulnerable and advising against direct sun exposure. Night-time temperatures are expected to become a growing burden: while early nights stay tolerable, forecasts show nights above 20°C toward the end of the week and into the weekend. Mormal warned that such warm nights place the greatest strain on the body, especially so soon after the previous heatwave.
