Windy использует данные Copernicus Copernicus Atmosphere Monitoring Service (CAMS). CAMS is implemented by the European Centre for Medium-Range Weather Forecasts (ECMWF) on behalf of the European Union.

Но сам коперникус строит другую карту)) https://atmosphere.copernicus.eu/charts/cams/nitrogen-dioxide-forecasts?facets=undefined&time=2021050300,3,2021050303&projection=classical_south_east_europe&layer_name=composition_no2_totalcolumn