No definitely not as long as a lot of dust hasn't accumulated on the paint.
If its outside for 12 hours and gets a lot of pollen and dust on it you can do a light waterless wash (wipe down) or quick detailer.
I do this all the time when the garage is really dusty and I leave it for 24 hours. Depending on the color of your paint and how concerned you are with micro swirls you could use a California duster. Thats the fastest way.