Depends on the area. Windfinder and Windguru are using the GFS model which has a resolution of only 50/100km.
For example for winds, in the US we are using NOAAs HIRESW with a resolution of 5km and in Europe we are using mostly WRF models from national agencies with 2-10km resolution depending on area.
For example for winds, in the US we are using NOAAs HIRESW with a resolution of 5km and in Europe we are using mostly WRF models from national agencies with 2-10km resolution depending on area.