In addition to there being a huge mountain range in the way. The Alps block/slow down a lot of the cold air currents that do make their way down from the polar regions. That's why cities like Turin and Milan still have cold climates in the north. Cold air still makes it's way over the Alps but is slowed and is reheated as it travels south so cities like Genoa/Florence/Rome are much milder in the winter.
In addition to there being a huge mountain range in the way. The Alps block/slow down a lot of the cold air currents that do make their way down from the polar regions. That's why cities like Turin and Milan still have cold climates in the north. Cold air still makes it's way over the Alps but is slowed and is reheated as it travels south so cities like Genoa/Florence/Rome are much milder in the winter.