Normandy is not exactly in the South, so you can expect rain all year. Although, in the summer, specially July and August, the chance of having rain is low.
September is usually a good month to visit, since there are less tourists, and the weather can be quite nice.

Winter in Normandy is usually one week of snow and freezing temperatures. The rest, rain and wind.

Currently, the weather and forecast in Vinnemerville, our home town is: