Custom Search     Prewitt Reservoir     I think that this is a great family lake. Says Virginia At Prewitt Reservoir you don’t see much precipitation. May is the wettest month with most rain, and February is when it's the driest. For the duration of the summertime months highs here at Prewitt Reservoir reach the 90's; the night is quite cooler of course, usually in the 50's. For the period of the winter the highs are usually in the 30's; nighttime lows in the 10's for Prewitt Reservoir.          Map Detailed Map Weather Local weather forecast