If you have one of the newer electric awnings, definitely drop one side to allow water to drain off if it's raining. I find our electric awning can't handle as much wind as the older manual model we had on our Sunline TT.
Personally, I never leave the awning out when not at the campsite, and retract it before going to bed. Depending on where you are, strong winds can happen very quickly....had it happen outside of Detroit and we almost lost an awning. DW was holding the tube while I started to get it down, and the wind caused the awning to lift and lifted my wife right off the ground!