That's a very broad question given the height you are flying as the winds do vary from 5-10 mph at ground level. If you are in an FCC area 1000m, CE area is 500m and these are ideal conditions with a fully charged battery, no signal interference and no wind.
I have achieved better than advertised conditions with a simple windsurfer fitted in still air, if you do fly with a breeze about, fly into it on the way out and with the breeze on the way back.