Belgium Braces for Second Heatwave After Deadliest June

Belgium is bracing for its second major heatwave of summer 2026, with temperatures forecast to reach 30–33°C across the country starting Monday, 13 July. The Royal Meteorological Institute (KMI) has issued a Code Yellow warning for the entire nation, including the coast, valid until at least 16 July, as the warning phase of the national ozone and heat plan has been extended through 17 July, according to VRT NWS.

A Nation Still Recovering

This second heatwave comes just weeks after the deadliest heatwave in modern Belgian history. Between 18 June and 1 July, 1,747 excess deaths were recorded — a 47.8% increase over the baseline and the highest heat-related mortality since Sciensano began tracking in 2000. Epidemiologist Toon Braeye called it “the deadliest heatwave of the last 30 years,” as reported by VRT NWS.

The toll was not evenly distributed. Wallonia suffered disproportionately, with 76% excess mortality (919 excess deaths), compared to 31.4% in Flanders (682 excess deaths) and 60.9% in Brussels (159 excess deaths). Sciensano suggests the heat dome centered over France led to higher ozone concentrations in Wallonia, and the region’s lower average life expectancy may have contributed to greater vulnerability.

Emergency Doctors Sound the Alarm

Emergency physicians who witnessed the June crisis firsthand are urging the public to take the second heatwave seriously. Dr. Stefanie Vandervelden of ZAS Antwerpen described the night of 27–28 June as unprecedented: “Between 8 PM and 3 AM, easily ten to fourteen patients per hour came in.” She reported seeing patients with body temperatures reaching 43°C, as detailed in an interview with Het Laatste Nieuws.

Dr. Laurens Heeren of UZ Leuven described a system pushed to its limits: “The entire system became saturated: ambulance services, emergency medical teams, admission capacity, and intensive care.” He noted that the severity of cases was exceptionally high, with elderly patients suffering from multiple conditions arriving after their reserves were already depleted.

A Warning for All Ages

A key message from doctors is that heat-related illness does not discriminate by age. Of the 1,747 excess deaths in June, 280 occurred in people under 65. Dr. Vandervelden emphasized: “Everyone thinks: I’m young, that won’t happen to me. We saw roofers, dock workers, people cycling 160 kilometers during the hottest hours.”

Dr. Dries Helsloot of UZ Leuven added that hot weather changes behavior in dangerous ways: “People drink more alcohol, spend more time outdoors, take more risks. There were more deaths from intoxications, drownings, violence, and accidents. Not everyone dies directly from heatstroke, but heat influences behavior.”

Cumulative Risk and the Second Wave

Doctors warn that a second heatwave can have a cumulative effect on already vulnerable populations. “A second heatwave can certainly have a cumulative effect,” Dr. Vandervelden said. “Especially elderly people with underlying conditions are often already weakened after a first heatwave. For them, a second heatwave can be the push too far.”

The KMI defines a nationwide heatwave as five consecutive days with maximum temperatures of at least 25°C in Ukkel, of which at least three days reach 30°C or higher. Current forecasts suggest these conditions may be met, though temperatures are expected to be less extreme than June’s record-breaking highs.

Policy Response and Preparedness

The crisis has prompted urgent policy action. Federal Health Minister Frank Vandenbroucke is pushing to take over the 1733 non-emergency medical number from Interior, citing failures during the June heatwave when the system was overwhelmed. The Risk Management Group is also working on a more comprehensive, integrated heat plan based on recent WHO guidelines, covering healthcare, social protection, infrastructure, work, education, and local governance, according to the FOD Volksgezondheid.

Local initiatives are emerging as well. Brussels has launched a €500,000 cooling project call, and volunteer-run cooling centers — such as a church in Grimde — are providing refuge for vulnerable residents.

Broader European Context

Belgium is not alone in suffering. The June heatwave was part of a wider European phenomenon: the UK reported approximately 2,700 excess deaths in May–June, Germany recorded an estimated 5,120 heat-related deaths, and France has placed 37 departments under Red Code with temperatures reaching 41°C. Researchers from Imperial College London noted that May–June temperatures in the UK were 3–4°C higher than they would have been without global warming.

What to Watch For

As temperatures climb this week, the key question is whether Belgium’s healthcare system — still recovering from June’s crisis — can handle a second wave. Doctors emphasize simple but life-saving precautions: stay hydrated, avoid direct sun during peak hours, check on vulnerable neighbors, and seek active cooling. As Dr. Helsloot put it: “Look out for each other. Call your parents, check on your neighbors, help people find cooling. That is literally life-saving in the coming days.”