Below is a worldwide map of the current wind conditions (updated whenever the map is idle). Clicking anywhere on the map will return a popup with the latitude and longitude coordinates of the location you clicked on. It is speculated that wind conditions > 6.67 m/s (24 km/h) and no precipitation will result in windy weather in Pokémon GO. Wind and precipitation data are provided as layers on the map below. Hover over the tiles in the upper right corner of the map and select the desired overlays.

Wind speed, m/s
0
2
3
6
12
25
50
100
Precipitation, mm
0
0.1
0.2
0.5
1
10
140