@Ondřej-Šutera thank you, this Information is well known. But some weather data provider offer more and Windguru, Ventusky and others reflect it. I like the gui of windy very much, but if it is not state-of-the-art, I cannot use it seriously.
@korina Thanks for your quick response. I hope you change your rendering indeed, because it is unusable in certain regions, especially in the mornings. Meteoblue's rendering style works better, IMHO.