Sultry Weather in Belgium with Rising Thunderstorm Risk

Belgium is experiencing several more days of sultry, humid weather with temperatures reaching up to 31°C, though the chance of thunderstorms is gradually increasing from Friday onward, according to VRT NWS. The warm and muggy conditions are expected to persist through the weekend before a cooler and more variable weather pattern arrives next week.

Current Conditions

Thursday brought plenty of sunshine across Belgium, with some high clouds and occasional cumulus clouds. The Royal Meteorological Institute (KMI) reported maximum temperatures ranging from 24°C in the High Ardennes to 30–31°C in the western part of the country. A light wind from the east to southeast accompanied the warm conditions. The chance of a local shower remained very small.

Thursday evening and night are expected to bring clear skies with broad clearings and mild minimum temperatures between 12°C and 19°C.

Increasing Thunderstorm Risk

Friday (May 29) will start sunny with high and mid-level clouds, but the atmosphere is forecast to become unstable in the afternoon, bringing a local chance of thunderstorms. It will be very warm and sultry, with maxima between 27°C and 32°C. The thunderstorm chance is expected to continue into the evening and night.

“Today we get plenty of sun and some cumulus clouds again, especially along the border with France and in the Ardennes. The chance of a shower is small. It will be very warm again. We’ll reach maxima of 30 or 31 degrees,” said Weervrouw Sabine, weather presenter for VRT NWS.

Saturday (May 30) will remain unstable with a chance of thunderstorms throughout the day. Temperatures will be a few degrees cooler than Friday: approximately 23°C at the coast, 27°C in the center, and locally 31°C in the far south.

Sunday (May 31) may see possible thunder showers in the southeast during the morning. Otherwise, the day is expected to be partly cloudy and mostly dry, though local showers remain possible. It will be cooler, with temperatures around 21°C at the coast and 24°C in the center.

Outlook for Next Week

According to Mancho.be, the weather pattern will become more variable and less warm from Monday onward. Monday is likely to remain dry in most areas, while Tuesday brings rain and occasional thundery showers. By Wednesday, temperatures are expected to drop to approximately 19°C in the center, with a continued chance of rain.

European Heat Dome Context

The sultry conditions in Belgium are part of a broader European heatwave caused by a “heat dome” — a high-pressure system with hot air from North Africa that has become stuck over Western Europe. As VRT NWS reported, the longer such a high-pressure area remains blocked, the more the air can heat up, “like a lid on a pot.”

The heatwave has triggered red alert warnings in four major Italian cities — Rome, Florence, Bologna, and Turin — where temperatures are exceeding 30°C. France has issued orange alerts for Paris and 13 departments, while Spain has heat warnings in place. The United Kingdom recorded its hottest May day ever on Monday, with temperatures reaching 35°C. Belgium has been more than 10 degrees warmer than normal throughout the week.

Climate Context

The World Meteorological Organization (WMO) released new climate forecasts on May 28, indicating that global warming will continue unabated over the next five years. The WMO projects a 91 percent chance of exceeding the 1.5°C threshold set by the Paris Agreement, and warns that the record temperatures of 2024 will likely be broken within the next five years.

According to climate scientists, heat domes are expected to become more frequent due to climate change, as warming of the poles causes weather systems to become blocked more easily.

What to Watch For

Residents and visitors in Belgium should prepare for a transition from hot, sunny weather to more unstable conditions with thunderstorm risks through the weekend. The cooler and more variable weather expected next week will provide relief from the current heat, though rain and thundery showers are likely to accompany the change.