Belgian heat wave caused highest excess mortality since 2000

Belgium’s heat wave at the end of June caused higher excess mortality than predicted by health institute Sciensano’s forecasting models, with 2,112 more deaths than usual recorded between June 18 and July 12, according to the Belga news agency on Wednesday.

The figure represented a relative excess mortality of 31%—the highest number of additional deaths and the highest relative excess mortality recorded during major heat episodes since 2000.

Unlike previous heat waves, when heat-related mortality was concentrated primarily among older women, the June heat wave also affected a higher proportion of older men and working-age men.

The effects varied across the country, with Wallonia more severely affected and a notable spike recorded in the Liegedistrict.

Sciensano’s scientific forecasting models had predicted high excess mortality based on meteorological and environmental risk factors, including minimum nighttime temperatures. However, actual mortality exceeded these forecasts, particularly during the peak on June 27 and 28.

Koen Blot, head of Infectious Disease Epidemiology at Sciensano, said factors such as baseline health status and socioeconomic conditions could potentially explain the difference between the forecasts and the observed mortality.

Speaking at a press conference on Wednesday, Blot emphasized that these explanations remain “hypotheses.”

Public Health Minister Frank Vandenbroucke said work is already underway on a new heat plan, noting the existing Heat and Ozone Plan is insufficient as a comprehensive preparedness plan. The current plan mainly serves as a phase-based communication tool, while the government aims to establish an integrated inter-federal “Heat-Health Preparedness & Response Plan” by summer 2027.