It’s on the cards that the official requirements for the Met Office to declare a heatwave in Belgium this week will be met. Belgium enters a heatwave after 5 consecutive days with temperatures at the Met Office in Ukkel (Brussels) above 25°C with 3 days with temperatures above 30°C.
Code Yellow until the end of the week
From tomorrow, Tuesday, through to Friday, a Code Yellow heat warning will be in force across the whole country, the Royal Meteorological Institute (RMI) has announced. On the coast, Code Green remains in force only for today turning yellow on Tuesday, whilst Code Yellow already applies in the rest of the country.
Under a Code Yellow warning, the RMI advises people to remain vigilant. Measures may also be taken to protect the elderly and vulnerable people, for example by ensuring they drink enough fluids and avoid prolonged exposure to direct sunlight.
The warning phase of the national ozone and heat plan has been extended until the end of the week, as maximum temperatures in many places are fluctuating between 30 and 33 degrees.
Belgium's àzone and heat plan features three stages to protect public health during hot weather. The warning phase (phase 2) triggers automatically when temperatures are predicted to reach or exceed 25°C for multiple days alongside high ozone.
It primarily involves:
Public Advisories: Daily warnings about rising temperatures and ozone levels.
Healthcare Activation: Extra monitoring for vulnerable people, children, and the elderly.
Preventative Care: Advice on increasing hydration, limiting strenuous outdoor activities, and protecting indoor air quality.
During this phase, health and regional authorities coordinate action plans for local communities. For instance, regional boards (like the Flemish Agency for Care and Health or Brussels Capital Region) begin rolling out protective measures for the vulnerable.
The Belgian Interregional Environment Agency tracks ongoing ozone metrics and detailed forecasts.
The weather in the week ahead
A sunny start to a very warm week with maximum temperatures of up to 33 degrees.
Today will start sunny, with possibly some low-altitude cloud over the coast and along the border with the Netherlands. Gradually, more cloud will move in from the south. Maximum temperatures will reach around 23 degrees in the coastal region and 28 to 32 degrees inland. This evening and tonight, it will be partly cloudy. It will remain mainly dry and mild, with minimum temperatures between 17 and 21 degrees.
On Tuesday, it remains warm and sunny with occasional cloudy spells. Towards the end of the day, there is a slight chance of thunderstorms in the south of the country. Maximum temperatures will range from 27 degrees on the coast to 31 to 33 degrees in most regions.
Wednesday will also remain very warm with plenty of sunshine and some clouds. There is still a chance of isolated thunderstorms in the south towards the end of the day. Maximum temperatures will again range between 27 and 33 degrees.
Thursday will remain uncomfortably hot and sunny, with maximum temperatures of 29 to 33 degrees. Thunderstorms are developing in France, which may cross the border into Belgium in the evening or overnight. On Friday, the weather will become increasingly unsettled, with a wave of thunderstorms. It remains oppressively hot, with maximum temperatures of 25 to 32 degrees.