Winterizing your Rain Barrel It is very important to winterize your barrel. Empty or drain your rain barrel and drain plug before storing for the winter. When possible, store your rain barrel in a protected indoor area. If the rain barrel must remain outside, either turn it upside down and secure it, or weight it down by storing garden equipment inside the barrel. Then put a heavy plastic bag over the top to prevent animal in-habitation and water accumulation which can freeze, expand, and potentially crack the barrel wall.