Belgium Heatwave: Code Yellow Extended, Water Crisis Deepens

Belgium is enduring another severe heatwave, with the Royal Meteorological Institute (KMI) issuing a Code Yellow warning for the entire country, now extended through Sunday evening, July 12. As temperatures are forecast to reach or exceed 32°C from Saturday onward, several Walloon municipalities are facing acute drinking water shortages, forcing authorities to supply water by truck to affected communities, according to VRT NWS.

A Deadly June Heatwave

The current heatwave follows a devastating June heatwave between June 18 and July 1 that claimed an estimated 1,747 excess deaths—the deadliest on record since measurements began in 2000. Sciensano, Belgium’s public health institute, reported a 47.8% excess mortality rate during that period, with Wallonia hit hardest at 76% excess mortality, compared to 31.4% in Flanders and 60.9% in Brussels.

“It is the deadliest heatwave of the last 30 years,” said Toon Braeye, epidemiologist at Sciensano, noting that the “unprecedented succession of warm nights” made this heatwave uniquely lethal. The deadliest single day was June 27, when 572 deaths were recorded.

Walloon Health Minister Yves Coppieters (Les Engagés) called the figures “worrying,” adding that the consequences “are clearly greater than those of the August 2020 heatwave and reach levels in some areas comparable to certain periods of the coronavirus crisis.”

Water Shortages Force Emergency Measures

As the new heatwave intensifies, the Société Wallonne des Eaux (SWDE) has been dispatching tanker trucks to supply drinking water to municipalities in the Ardennes and Famenne regions, particularly Vielsalm and surrounding areas. RTBF reports that during peak summer periods, the SWDE deploys up to 10 tanker trucks per day.

“We have to use trucks to supplement the water towers, because otherwise there is a risk of running out of water,” explained Benoît Moulin, SWDE spokesperson.

The shortages stem from the geological composition of the Ardennes and Famenne regions, where the subsoil consists of compact schist and rock that prevents natural groundwater infiltration and storage. While the SWDE maintains that Wallonia has sufficient water reserves for up to two years of consumption, these reserves are unevenly distributed.

To address this, the SWDE has developed interconnected water networks—known as “autoroutes de l’eau” or water highways—that transport water from surplus regions to deficit areas. Stavelot was connected to the Stembert/Gileppe dam system in 2019, and Vielsalm is awaiting a similar connection. Until then, tanker trucks remain the primary emergency solution.

Agathe Defourny, policy coordinator at Canopéa, a Walloon environmental coalition, warned that relying on tanker trucks “has a negative impact. It masks the water stress that exists in Wallonia.” She called for a comprehensive regional water management strategy, noting that “this water stress will eventually concern the entire region.”

Political Fallout Intensifies

The heatwave crisis has sparked sharp political criticism. Opposition party leaders have accused the federal government of failing to protect citizens. PS leader Paul Magnette charged the government with “lethargy,” stating that “not a single measure has been taken by the federal government. Citizens have been left to their fate.”

Groen party leader Aimen Horch called for an emergency plan, urging the government to “provide public cooling, swimming spots, and an air conditioning plan for care homes and schools.”

Health Minister Frank Vandenbroucke (Vooruit) acknowledged that the 112 emergency number failed during the heatwave peak, with wait times reaching up to 10 minutes. He has proposed transferring the 1733 non-emergency medical number from Interior to Health to improve coordination.

Broader European Context

Belgium’s heatwave is part of a wider European pattern of intensifying climate extremes. Germany recorded an estimated 5,120 heat-related deaths during its June heatwave. France experienced its hottest June on record, with an average temperature of 22.7°C—3.8°C above normal. Spain issued Code Red warnings in three regions with temperatures reaching 42°C, while Portugal declared a state of alert for wildfire risk.

An AWAC report from June 2025 estimated that climate change-induced water stress could cost Wallonia €155 million per year through reduced river flows, drinking water shortages, and consumption restrictions.

What’s Next

The warning phase of the ozone and heat plan has been activated across all regions due to the combination of high temperatures and elevated ozone concentrations. The Risk Management Group (RMG) is expected to issue recommendations for strengthening Belgium’s heat preparedness, including better protection for vulnerable groups and improved coordination of emergency services.

As temperatures are forecast to remain above 30°C through the weekend and into next week, the pressing question remains whether Belgium’s infrastructure and emergency systems are adequately prepared for a future of increasingly frequent and intense heatwaves.