Venice is nearly always humid. The water that makes the city so unique also keeps the humidity level at about 80%. Keep this in mind, as the temperatures will feel more extreme. December-February, the average temperature is 32-37 F/0-3 C. Fog and wind often roll in with the coldest months. In summer, the humidity can become very uncomfortable. The hottest months are July and August, with average temperatures ranging 86-91 F/30-33 C.
In the fall and winter, sometimes even through spring, the water often rises above usual levels and floods many of the streets and squares, usually for a few hours at a time. Called acqua alta, or high water, the locals are used to dealing with it—tall rubber boots become de rigueur.