If you’re hoping to get lost in the rain on your romantic getaway, check out these details about year-round temperatures in Gennevilliers: The hottest months are usually August and July with an average temp of 66°F, while the coldest months are January and February with an average of 42°F. The snowiest months in Gennevilliers are February, March, January, and May, with each month seeing an average of 5 inches of snowfall.