When is best to go to Venice ? Here is the kind of weather you can expect
The weather in Venice is characterized by a hot humid summer, cold winter and rainfalls spread quite evenly across the year.
SUMMER: Temperatures in summer have high averages around 28 C (82 F) with peaks at and above 38 C (100 F) during th day. Nights are cooler averaging 18 C (64 F). Rains are frequent making the weather generally humid. Thunderstorms are common. July is the month getting the greatest number of hours of sun, 300. Light clothes and sunscreen are recommended.
WINTER: Visitors coming during winter should pack warm clothes (coat, scarf, gloves, hat). The temperature drops significantly starting in October with low averages around 0 C (32 F) in December - January and highs around 6 C (42 F). January to March are the dryest months of the year. December is the month with the lowest number of sunshine hours, just 70. The high level of humidity coming from the lagoon will make you feel colder than what the temperature would suggest.
May and September are very nice months in terms of weather. Spring is the busiest season for tourism so the city is crowded. February is still cold and it's the month of Carnival so it's a fun time to visit the city. If you want to participate in local festivities you may want to be in Venice on April 25th when they celebrate the feast of Saint Mark (read more here) and for the Festa del Redentore the most important holiday of the city (third Sunday of July, more information here).
During a visit to Venice you may experience acqua alta, the flooding caused by an interplay of high tide and special weather conditions. It may happen anytime of the year, but more often during winter time. Read more about acqua alta here.
When looking the charts please note that they are based on average temperatures and rainfalls. Peaks can be significantly different than averages.