I check it out every time I leave for a ride. It tends to change direction quite a bit around here (I live by the ocean). I ride in areas that are true wind tunnels, so I always, always have a head or tailwind of 15 km/h, and most often much more (35 is not unusual, 50 has happened a few times recently). I sort of like being mentally prepared for it, otherwise I get discouraged when I find out!