Temperatures in Belgium could reach up to 30°C in some places on Tuesday, unusually warm for late September, according to David Dehenauw, head of the Weather Forecasting Service at the Royal Meteorological Institute (RMI).
Tuesday will be “unseasonably warm,” the RMI forecasts. Temperatures will range from 24-25°C by the coast and in the Ardennes to 29-30°C locally, mainly in the east of the country.
“It could indeed reach 30°C in very localised areas,” Dehenauw told De Morgen. “The latest computer models suggest 29°C, but ultimately that matters little when looking at the big picture.”
If the day record of 27.3°C is broken – "and it looks likely this will happen," he said – it will be the warmest 29 September on record.
Southern winds
The high autumn temperatures are caused by a lingering high-pressure system over Belgium. “It is also still very hot and very dry in Spain and France, but that is all linked. I saw that on certain days in southern Spain, temperatures reached 37°C. The air is coming our way from the south.”
However, there is some relief, according to the RMI: rain is on its way to Belgium from the west during the course of Wednesday afternoon. “It will continue to rain tomorrow evening and on Thursday morning, causing the temperature to drop slightly.”
While this short period of rain is expected to be followed by another dry spell, Dehenauw said that the dry conditions will not be accompanied by such high temperatures this time. The sun will still shine regularly from Friday, but temperatures will be around 17-18°C.
A person using a hand fan pictured in Brussels. Credit: Belga/Emile Windal
Looking forward to the rest of autumn, the weather models predict that the trend towards higher temperatures is set to continue until the end of the year, and potentially even well into January.
“To summarise those projections, it will be one to two degrees warmer than normal every month until the end of December,” Dehenauw said. “That means there is a 75-80% chance that we will experience the warmest year on record in Belgium.”
Currently, the record stands at 12.2°C, averaged over the whole year. This was recorded in 2020 and again in 2022. Now, Dehenauw sees “a reasonable chance” that this average will be exceeded.
“We do not see a nice straight line when it comes to rising temperatures, as that would mean the record is being broken year after year,” he said. “That is not happening, but the trend line is clearly rising.”
