The direction of wind arrows on weather map is the direction of an arrow "flying" with the wind like the animated particles do (it is NOT the direction shown by a wind vane). Same for the wind symbols which are called wind barbs, they are a simplified design of an arrow flying with the wind. And so, for a northerly wind blowing from North, the arrow is pointing to the South.
Did you compared several models for your location?
You should know that weather forecast models have a resolution of several km (25 km for GFS), so don't expect huge accuracy over areas with mountains, valleys, etc.
Hallo @petra-pik, danke für die Information. Das erklärt, warum es in Windy schlechter geworden ist. Ist davon dann nicht auch Meteoblue betroffen? Oder beziehen die ihre Daten von einem anderen Satelliten?