It is warm and the heat will continue in the coming days. Starting tomorrow (Tuesday, August 12), the National Heat Plan will be in effect for the entire country. In addition to the heat, humidity will also rise, which means it may feel stuffy. The southeast of the country will be the warmest. Thunderstorms may develop on Thursday. From Friday, it will be less hot and less stuffy.

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. 

Advice during heat:

• Stay out of the sun
• Use sunscreen, even in light cloud cover. Check the UV index in the KNMI app
• Drink enough water, even if you are not thirsty. Also take water with you on the go
• Avoid heavy physical activities between 12:00 and 18:00 
• Pay extra attention to people in your surroundings who may need your help
• Also take good care of your pets
• Keep your home cool: use shading, 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 entire country. Do you want the weather forecast for your own place? 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 will be active starting Tuesday, August 12. The decision to activate the National Heat Plan is made by the RIVM after consultation with the KNMI. The likelihood of sustained warm weather, as well as the expected nighttime temperature 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 additionally, heat is retained better due to 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 place of residence, it is often seen that it is warmer in the city. The colors on this map give you a general idea and show temperature differences between places in the Netherlands.

Next Year New Heat Index

One type of heat is not the same as another. When does it really feel hot? The KNMI is developing a heat 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 starting summer 2026, so everyone can see how heavy the heat feels at that moment. This helps the Netherlands to be better prepared for heat, now and in the future.

National Heat Plan Not the Same as Heat Wave 

The National Heat Plan is activated based on the weather forecast. A heat wave can only be established retrospectively. A heat wave 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 are above 30 degrees.