Thousands of Dutch amateur weather stations help KNMI boost forecast accuracy
About 1,000 amateur weather stations across the Netherlands are providing data that the Royal Netherlands Meteorological Institute (KNMI) uses to create more detailed weather maps and refine flood risk assessments, NOS reports.
Data from the amateurs is now used in maps of temperature, humidity, and wind speed, which are shared through the KNMI app to about 1.2 million users.
“These maps are much more detailed than ones based solely on official stations,” KNMI researcher Gerard van der Schrier told NOS. They reveal patterns such as cooler coastal temperatures, warmer urban areas, and lower wind speeds on the Veluwe and Utrechtse Heuvelrug. Van der Schrier noted that amateur measurements are less precise, but the KNMI accounts for inconsistencies when creating maps.
Sjaak de Wit of Utrecht operates two stations—one behind his home and one at his allotment—that automatically measure temperature, humidity, rainfall, and air pressure.
Data from these stations is uploaded directly online and shared with the KNMI. “The weather has been an interest for a long time,” De Wit told NOS. “It started in my youth by recording temperatures daily. Nowadays, the equipment measures automatically, and the results are shared immediately.”
While most hobbyists buy ready-made stations costing hundreds to over a thousand euros, De Wit built his own. “Electronics is my hobby,” he said.
The KNMI’s network of amateur stations complements the 37 official stations, which are mostly in remote, open-field locations.
De Wit said his own motivation is tracking weather developments. “You can see exactly where the cold is, where the fronts are, and how they move,” he said.
