Theres no right or wrong answer to your question, for some it will just be a necessity to house certain items they may have stowed in the caravan when travelling.
Unless I need it up, I leave it until i'm ready to put it up.
hi Kevin,
I tend to leave it untill it dries up a bit, not that I mind getting wet you understand but putting the awning up over damp grass causes oodles of condensation inside the awning when it warms up a bit.
having said that I don't mind if it has been raining prior to arriving as then you are sure that the awning is not going to cover lake windermere next time it rains.