We are approaching a few very warm and sunny days. Starting today, Sunday, June 29, the National Heat Plan is active in the provinces of North Brabant and Limburg. From Monday, June 30, the National Heat Plan will apply to the whole country. The heat may last until Thursday, with the hottest days on Tuesday and Wednesday.

Heat can be dangerous. Especially the elderly and people with vulnerable health are sensitive to it. During heavy physical activity, anyone can experience symptoms such as dehydration and overheating. The KNMI warns with a yellow code for heat if we expect a maximum temperature of 35 °C or higher for 1 day. A yellow code has been issued for North Brabant and Limburg starting Sunday morning at 10:00 and is expected to be extended to the whole country tomorrow. 

Advice in heat:

• Stay out of the sun
• Use sunscreen, even in light cloud cover. Check the UV index in the KNMI app
• Drink enough water. Also take water with you on the go
• Avoid heavy physical activities between 12:00 and 18:00 
• Keep a close eye on people with vulnerable health in your surroundings 
• Also take good care of your pets
• Keep your home cool: use sun protection, close windows and doors during the day and ventilate your house early in the morning
• Do not leave children and pets in a closed car, even for a few minutes
• Check zwemwater.nl if you plan to swim in natural water.

Check the current weather forecast for the whole country. Do you want the weather forecast for your own location? Download the KNMI app for iOS in the App Store or for Android in the Play Store.

National Heat Plan active

The National Heat Plan has been active since Sunday, June 29. The decision to activate the National Heat Plan is made by the RIVM after consultation with the KNMI. The likelihood of persistently warm weather, but also other factors such as expected night temperatures and humidity play an important role in this decision. 

Warmer in the city

Most cities in the world are warmer than the surrounding countryside. In cities, heat is produced, and heat is also better retained by buildings than in rural areas. This can lead to a temperature difference of several degrees in cities compared to the countryside. This effect is also known as the urban heat island effect.

In the KNMI app, there are maps with measurements, including temperature in the Netherlands. On this map with the current temperature for your residence, it is often seen that it is warmer in the city. The colors on this map provide a general picture and show temperature differences between places in the Netherlands.

Next year new heat strength index

One type of heat is not the same as another. When does it really feel hot? The KNMI is developing a heat strength index together with TNO, RIVM, and VU to better assess how burdensome heat is for humans. In this new index, temperature, humidity, solar radiation, and wind are combined. The index is expected to be available via the KNMI app from the summer of 2026, so everyone can see how heavy the heat feels at that moment. This will help the Netherlands to be better prepared for heat, now and in the future.

National heat plan is not the same as a heatwave 

The National Heat Plan is activated based on the weather forecast. A heatwave can only be established retrospectively. A heatwave occurs when it has been at least 25 degrees in De Bilt for a minimum of 5 consecutive days, of which at least 3 days above 30 degrees.