The weather in Venice, located North-East of Italy, has many changes along the year. July is the hottest month of the year and January is the opposite being the coldest month of the year. During November, between autumn and winter, Venice suffers the “Acqua Alta”, which is an almost-daily flooding.
During the Acqua Alta, the lowest areas of Venice flood; in more critical cases 96% of the streets in Venice are under water. The Acqua Alta happens when the sea level grows more than 90 cm. (35.4 inches) by an official definition.
If in the city an unusual higher tide is anticipated, the sirens sound 3-4 hours to notify people, but only if the level is 110 cm or higher evacuation starts.
Venice weather in spring (March - May)
This season is one of the most beautiful with a usually comfortable temperature, though mass tourism season does not start yet.
In spring the weather used to be sunny but sometimes it changes to rains and thunderstorms. Daytime turns longer and in May you can witness around 10 hours of daylight. And the temperatures vary between 13°C and 22°C (55°F and 72°F).
Venice weather in summer (June - August)
Summer is very radiant, hot and humid. And the evenings are usually very comfortable, except in the case of Sirocco. The temperatures during summer vary between 25°C (80°F) and 31°C (90°F), although these recent years the temperature is reaching 40°C (104°F) which is not favorable to people in Venice.
Venice weather in autumn (September - November)
The sunsets through this season are spectacular and provide a romantic atmosphere. The daylight hours are from 8 to 9 hours a day, with an average temperature of 15°C (59°F). In the early autumn weather is usually dry, because rainy season begins around the end of November.
Venice weather in winter (December - February)
During this season, the days in Venice are sunny and cold with few hours of daylight in December, this has a big change in February when the days are more extended but the temperature is near 8°C (46°F). During this season the probability of fog, rain or Sirocco is very high.