Belgium Braces for Tropical Heat and Severe Thunderstorms
Belgium is set to experience a dramatic weather shift this week, with tropical temperatures soaring to 34°C and the possibility of the country’s first official heatwave of 2026. However, the heat will be short-lived as severe thunderstorms with hail, heavy rain, and strong wind gusts are forecast to strike on Friday, June 19.
Heatwave Conditions on the Horizon
After an unusually cool and rainy start to June, temperatures are climbing rapidly. According to VRT NWS, the mercury is expected to reach 30°C or more from Thursday onward, with Friday potentially being the hottest day at up to 34°C. The Royal Meteorological Institute (KMI) defines a national heatwave as at least five consecutive days above 25°C in Ukkel (Uccle, Brussels), with at least three of those days exceeding 30°C. Current forecasts suggest this threshold could be met between Tuesday and Saturday.
Severe Thunderstorms Threaten Friday
The heat will come with a dangerous caveat. Weather presenter Sabine Hagedoren warned: “Friday afternoon and evening we expect thunderstorms that could be locally severe, with heavy precipitation in a short time, hail, and strong wind gusts.” The storms are expected to develop in the afternoon and continue into the evening, posing risks of local flooding, property damage, and dangerous driving conditions.
HLN weerman Frank Duboccage confirmed the outlook: “Friday will be even warmer with temperatures that can climb to 34 degrees, but in the afternoon the chance of severe thunderstorms increases.”
Health Warnings Activated
In response to the forecast, authorities have taken proactive measures. On Monday, June 15, the warning phase of the federal ozone and heat plan (ozon- en hitteplan) and the Flemish Heat Action Plan (Vlaams Warmteactieplan) were activated by Ircel and the Departement Zorg. Code yellow heat warnings are now in effect across most of Belgium, excluding the coast.
Climate doctor Jules Vertriest of the Departement Zorg issued clear advice: “Drink enough, stay out of the sun, limit strenuous activities during the hottest hours of the day, keep yourself and your home cool, and take care of others. Visit a neighbor, family member, or acquaintance who might need help.”
Flemish Minister of Care Caroline Gennez emphasized the vulnerability of residents in care facilities. “That’s why it’s important that facilities take timely measures to provide residents with sufficient cooling, rest, and hydration,” she said, as reported by De Morgen.
Weekend and Beyond
After Friday’s storms pass, the weekend is expected to bring mostly dry and sunny weather with temperatures remaining above 30°C. However, uncertainty remains about Monday, June 22. Some weather models predict local temperatures up to 36°C, but meteorologists consider this unlikely, with around 31°C deemed more realistic. Additional thunderstorms are also expected on Monday afternoon and evening.
Public Health and Infrastructure Concerns
The combination of extreme heat followed by severe storms presents dual risks. The elderly, young children, people with chronic conditions, and those with limited social networks are particularly vulnerable during heatwaves. The World Health Organization has reported over 200,000 heat-related deaths in Europe in the past four years, underscoring the seriousness of the situation.
Severe thunderstorms with hail and strong winds could also cause local damage to infrastructure and agriculture. The KMI’s official heatwave definition and the federal ozone and heat plan provide the framework for Belgium’s coordinated response to these weather extremes.
What to Watch For
Residents are advised to stay updated on local weather warnings, prepare for both extreme heat and potential storm impacts, and check on vulnerable neighbors. Whether Belgium officially records its first heatwave of 2026 will depend on actual temperatures in the coming days, but the message from authorities is clear: prepare for a week of weather extremes.