KNMI weather data

Dutch weather on a date shows what the weather was like on a day of your choice, from 1901. The measurements come from the KNMI, the Royal Netherlands Meteorological Institute.

What the KNMI measures

The KNMI has about fifty weather stations in the Netherlands. Every day each station measures, among other things, temperature, precipitation, sunshine, wind, cloud cover and humidity. The KNMI publishes these daily data (page in Dutch) per station, from the start of that station. De Bilt has measured since 1901, four stations since 1906 and most others since 1951 or later.

Of the more than forty values per day we use only these:

• the average, lowest and highest temperature;
• the amount of precipitation and how long it rained;
• the hours of sunshine;
• the average wind and the highest gust;
• the cloud cover;
• the humidity.

We convert them to ordinary units. The KNMI gives temperature in tenths of a degree, for example.

The nearest station

You choose a place, a postcode or your own location. We look for the nearest station that measured an average temperature on that day. For a day before 1906 that is always De Bilt. The distance is shown, and on the map you see the station and your search point.

The station can be kilometers away. The weather can differ from place to place: a shower does not fall everywhere.

What is normal

Next to the measurements of that day you see Normal. That is our own average over the years 1991 to 2020, at the same station, over the 15 days around the same date: 7 days before and 7 after. We take 15 days because a single day over 30 years is too erratic. If the station measured in fewer than 20 of those years, we leave Normal out.

It is not an official climate figure from the KNMI, but an average we calculate ourselves from the measurements.

How current it is

The KNMI adds yesterday's measurements the next morning. The KNMI checks the data on working days and adjusts it where needed, so the latest days can still change. We fetch everything again every morning. If yesterday is not there yet, try again later.

Things to bear in mind

• No trends. Stations have sometimes been moved and the measuring instruments have changed. The KNMI therefore writes that most series are not suitable for determining trends. Comparing a day with the average around that date is possible. We do not show a trend or record over the whole century.
• Daily measurements only. No hourly values, forecasts or warnings.
• Very little. If precipitation or sunshine was less than 0.05 mm or hours, it says less than 0.1 mm (or hours).
• Not measured. If the station did not measure something that day, it says not measured.

License and source

The daily data is open data under CC BY 4.0. The KNMI asks for the credit Source: KNMI, and for a statement that the KNMI is not involved in what you make with it. We do that: the KNMI is not involved in this tool. See also the KNMI copyright page (in Dutch).

Where the map comes from is described in Maps and addresses. How to share your location is in Sharing your location. How we update and monitor the data is described in How we keep everything current.

Tools for this guide

• Dutch weather on a dateTemperature, rain and sunshine on any day since 1901

The Sumish editorial team