Belgium is bracing for a prolonged period of extreme heat, with temperatures forecast to exceed 36°C as an official heatwave continues to grip the country. According to Meteovista, the combination of high humidity and elevated nighttime temperatures is creating “tropical” conditions that prevent effective cooling. This current surge follows an official heatwave declaration in Ukkel on June 21, 2026, marking a stretch of at least five days where temperatures reached 25°C, including three days of tropical heat above 30°C.
How does this heatwave compare to historical records?
Meteorologists are monitoring the current event against historical benchmarks to determine its severity. While the current heatwave began mid-June, its duration remains the primary point of interest. Data from the Royal Meteorological Institute indicate that the longest official heatwave in Belgian history occurred in 1947, lasting 19 days between August 10 and August 28. Current forecasts suggest this week’s heat could mirror such sustained intensity, though it has yet to reach the record-breaking duration of the 1947 event.
Why is the combination of humidity and heat dangerous?
High humidity levels are exacerbating the impact of the heat, leading to what meteorologists describe as “plaknachten” or “sticky nights.” When nighttime temperatures remain high, the human body cannot cool down effectively, increasing the physiological strain on residents. According to Meteovista, the high dew point prevents the typical nighttime relief, making the environment feel significantly warmer than the ambient air temperature suggests.
What are the risks of high UV radiation?
Health authorities warn that the current weather pattern includes a very high UV index, peaking between 13:00 and 15:00. Meteovista reports that the zonkracht (sun strength) is reaching levels of 7 or 8. At these levels, unprotected skin can sustain sun damage in as little as 10 to 15 minutes. Experts recommend consistent use of broad-spectrum sunscreen and protective clothing during these peak hours to mitigate the risk of heat-related skin damage.
Did you know?
An official heatwave is defined by the Royal Meteorological Institute as a period of at least five consecutive days where the daily maximum temperature in Ukkel reaches 25°C or higher, provided that at least three of those days reach 30°C or higher.
Frequently Asked Questions
- What is an official heatwave? A period of at least five days with temperatures above 25°C, including three days of 30°C or more.
- How fast can I burn in this weather? With a UV index of 7 or 8, skin damage can occur in 10 to 15 minutes.
- Why are the nights so hot? High humidity levels trap heat, preventing the atmosphere from cooling down significantly after sunset.
Are you managing to stay cool during this heatwave? Share your tips for beating the heat in the comments below or subscribe to our weather newsletter for daily updates on temperature trends.
