KNMI

KNMI's API provides excellent access to Dutch meteorological data with comprehensive documentation. It uses API key authentication and follows open data principles under CC-BY-4.0 licensing.

The RESTful API covers weather observations, forecasts, climate data, and historical records extensively. Multiple data formats are supported (NetCDF, JSON, XML), with reliable real-time updates. However, it's specific to Netherlands/European weather data and requires understanding of meteorological concepts. It's an excellent choice for weather applications in the Netherlands, offering authoritative data from the national weather service.