Trails of Wind has created a fascinating global database of the orientation of airport runways around the world. As they note, “runways generally point in the wind direction, as aircraft take off and land more easily upwind.” There’s an excellent interactive map at their site which you should check out.
I was really struck by how wind patterns obvious differ between the African coasts and the interior. As the screenshot above shows, coastal airports have runways that are perpendicular to the coast, presumably reflecting wind coming in off the sea. Further inland, however, virtually all airports have east-west runways, showing the flow of wind across the continent. (If it’s difficult to see the runways in the screenshot, try tilting your laptop screen forward a bit, or just click through to the interactive map.)