Home Information Weather in Versilia and Tuscan Weather in Versilia and Tuscan Weather of Versilia and Viareggio. Weather bullettins. Weather of Versilia and Viareggio, temperatures and climatic conditions Each year, sunny days are approximately 270, with an average temperature of 24,5ᵒ during the summer and of 9,4° during the winter.During the summer, seawater reaches 30ᵒ, salinity is at 3,85ᵒ approximately and the temperature of the sand on the surface reaches approximately 50ᵒ. Thanks to its proximity to mountains and sea, (as the crow flies, there are 15 kilometres from the pier of Forte dei Marmi to the peak of the Pania della Croce, 1859 metres above sea levels .)During the summer we have a mild climate; during the winter, sea releases heat to mitigate the cold winter.