12 people were killed on the southern Italian island of Sicily, nine of the same family. The emergency services said on Sunday that the number of weeks across Italy would exceed 30.
Six Italian regions are still on alert after storms.
The bodies of nine people had been found in their house in Casteldaccia in the Palermo region, next to a small river that had blown its shores, rescue workers said. The victims included a one-year-old baby and children between the ages of three and fifteen.
Three other members of the same family managed to escape, one of which by climbing on a tree, reported the news agency Agi.
"It's an immense tragedy," said the local mayor.
In a separate incident, a 44-year-old man was found dead near Vicari, also in the Palermo area.
He had tried to reach a gas station that managed to help a trapped colleague there. A passenger in the car is missing.
Rescue workers are also looking for a doctor who was forced by the storms to park his car near the town of Corleone after trying to drive to work in the hospital.
Two other people, a man and a woman, died when their car hit the floodwaters in the Agrigente region, just south of the island.
Troops were deployed to check the state of the main roads of the Mediterranean island on Sunday.
At the beginning of this week, flooding in Sicily had closed many roads and mayors closed schools, public parks and underpasses.
– A week of deadly storms –
Italy was hit by a series of deadly storms last week, especially in the north and around Venice. In total, they have claimed more than 30 casualties, including the deaths in Sicily, and have caused massive damage and disruption.
Forests in the northeast of the country have been flattened like matches.
Italian Interior Minister Matteo Salvini described the devastated area and published in a Sunday tweet after flying over the Alpine town of Belluno.
The picturesque fishing village of Portofino, near Genoa, a famous resort on the Italian Riviera, was only reachable by sea after the main road collapsed. An emergency path designed to let the residents out was considered too dangerous.
Trees that covered the mountains of the Dolomites were reduced to matches that were flattened by the winds that swept through the Veneto region on Thursday.
"It's like an earthquake," said Veneto governor Luca Zaia. "Thousands of acres of forest have been knocked down like a giant electric saw."
The canal city of Venice on the northeast coast of Italy has also suffered some of its worst floods and has had to withstand wind speeds of up to 180 kilometers per hour.
The Italian civil protection authority described the weather this week as "one of the most complex meteorological situations of the last 50 to 60 years".
The heavy rains caused rivers to burst across Sicily, causing deadly flooding on the island
The recent deaths in Sicily increase the number of storms in Italy to at least 30
Storms have caused havoc in the port of Rapallo near Genoa on the Italian north coast last week
The canal city of Venice has experienced strong winds and some of the worst flooding in years