Authorities in Venice placed raised walkways along streets as locals and tourists treaded through the high water that has flooded much of the lagoon city.
Venice’s tide forecast office said the water level peaked at 1.87 metres on Tuesday evening, but an even higher tide was expected overnight.
The “acqua alta” flooded cafes, shops and some tourist sites on Tuesday.
Sirens warned people of the rising water, and as a precaution, childcare centres were ordered closed.
Meanwhile, heavy rain, hail and winds of more than 100 kilometres per hour caused damage and school closures in many part of southern Italy.
Since Monday night, firefighters in the south have been called out at least 460 times to respond to storm damage, the fire service wrote on Twitter.
In the region of Basilicata, a whirlwind ripped the roofs off two homes in the town of Policoro, while the famous city of Matera was flooded causing serious damage to buildings in the historic centre.
In Puglia, a truck crashed into a motorway barrier after losing control in heavy rain on Tuesday, and a large number of olive trees in Salento were reportedly damaged by winds of over 100 kilometres per hour.
Further south in Sicily, a tornado was reported off the coast of Syracuse.
While no injuries have been reported so far, there are widespread reports of damage to homes, businesses, electricity supplies and crops across parts of the nation, particularly in the south.
Bad weather will continue to batter Italy this week, with no real let-up forecast for several days.
