In Uccle, a reference point for meteorologists, the maximum temperatures had not exceeded 24.9 degrees Celsius at 4:20 p.m. on Monday. For a period to be considered a heat wave in meteorological terms, a minimum of five consecutive days must be recorded in Uccle with a temperature of at least 25 degrees, including at least three of 30 degrees or more.
The 25 degrees “required” to experience the first heat wave of the year were therefore “missed” by little.
The longest heat wave in the history of Belgium since the beginning of the 20th century dates from 1947. It lasted 19 days and extended from August 10 to 28. The 1976 heat wave was also quite long, lasting 17 days. In 2018, two other heat waves were recorded, one from July 13 to 27, and the other from July 29 to August 7.
Even if the feeling of heat is omnipresent, night frosts are nevertheless possible at the end of the summer. Also in Belgium. Thus, in Elsenborn (province of Liège), the mercury has already fallen to -1.3 degrees this month. At 538 meters above sea level, a minimum temperature of 0.7 degrees was also recorded on Monday, according to the meteo-BE.net site.