Italy has a predominantly temperate climate with regional variations.
In summer, the northern regions of Italy are warm with occasional rainfall. The central and southern regions are warmer and drier.
In winter, northern Italy is dominated by cold, damp and fog. Temperatures in the south are slightly more favourable, averaging 50-60ºF (10-20ºC).
Located in north-eastern Italy, Venice has a climate that changes dramatically throughout the year. In winter the temperature can drop below freezing, while in summer the temperature can rise to 35ºC. The hottest month is July and the coldest is January.
Humidity tends to be high throughout the year due to the canals. During the winter, the night-time drop in temperature causes mists to hover over the canals.
In the autumn and winter months Venice is susceptible to flooding, this phenomenon seems to occur often in November. In Venice this phenomenon is known as Acqua Alta and is linked to the tides of the lagoon. Acqua alta lasts only a few hours and can create many inconveniences such as flooding in the lower areas of Venice. When Venice floods, the calle also flood, making it very difficult to get around on foot. By definition, high water occurs when the level is more than 90 cm or 35.4 inches above sea level.
When a higher than usual tide is expected in the city, city sirens sound 3-4 hours in advance to warn the population. It is therefore advisable to plan your visit with this phenomenon in mind.
Spring is one of the best seasons to visit Venice. There are not many tourists and the temperatures are generally pleasant. Spring weather is sunny, but there are also some chances of rain. The days begin to lengthen in May and reach about 10 hours of daylight. Average temperatures for this season are between 12°C and 21°C (53°F and 70°F).
The summer climate in Venice is sunny, warm and humid. The average summer temperature ranges from 25°C to 31°C (80°F and 90°F). In recent years it has reached 40°C (104°F) but evenings are often quite comfortable.
Venice's autumn weather is generally pleasant and offers beautiful sunsets. The beginning of autumn is usually quite dry and the rainy season starts around mid-November. The average temperature is about 15°C (59°F).