10km/h
Wind felt on face
Wind vane begins to move
20km/h
Small flags extended
30km/h
Wind raises loose paper, large flags flap and small tree branches move
40km/h
Small trees begin to way and large flags extend and flap strongly
50km/h
Large branches of the trees move, telephone wires whistle and it is hard to use an umbrella
60km/h
Trees bend and walking against the wind is hard