Honestly - it's a lot nicer flying when it's not windy, but light to medium wind typically isn't an issue. If it gets heavy, I'll usually call it a day. If you're just starting out, definitely try to fly on days with as little wind as possible while you get used to the controls. Also, depending on your flight control board, things should be pretty stable, even in the wind for the most part... where you'll run into the most problems is being comfortable with knowing how much stick to give the copter when flying with or against the wind. It can make a huge difference sometimes. I had a buddy fly his copter over a river and since he was flying with the wind, he thought nothing of it. On the way back, he was flying into the wind and had to give it everything just to get back across. Since he didn't have a boat and there were no bridges near by, he couldn't just land it on the other side and walk over and pick it up, so it got pretty intense. That was in pretty heavy wind though.