cloudy [cloudier, cloudiest]◼◼◼(covered with or characterised by clouds) adjective [UK: ˈklaʊ.di] [US: ˈklaʊ.di]It'll be cloudy. = Il fera nuageux.
overcast◼◼◻(covered with clouds; overshadowed; darkened) adjective [UK: ˌəʊv.əˈk.ɑːst] [US: ˌoʊv.ə.ˈk.ɑːst]Johnorrow will be overcast. = Ce sera nuageux demain.