difficult to put a hard number on it. Whats your experience and what plane? I have flown in up to 45 knots steady wind. Makes it fun. I wouldn't suggest it for a low timer though. Some must quit in a breeze depending on the plane. You have to start with low wind and work up till you are comfortable, and then different pressure systems cause different turbulence for you to deal with. Its all good. Learn it and you will be a lot better pilot. Dont' bite off more than you can chew to start though