@Sergio-Barriga-Vitorino
The wind direction in Windy is displayed as it is usually done in weather maps.
In this example

Capture d’écran 2025-03-07 à 07.39.31.png

the wind is blowing from the South direction, from 180°.
Consider that the small arrow is flying in the wind stream, from South to North, as the wind particles do.