Lake Como Geography & Climate

Lake Como occupies a valley carved by glaciers and then drowned, which is why it is long, narrow and startlingly deep — about 410 metres at its deepest, the deepest lake in Italy and among the deepest in Europe. Its floor lies well below sea level.

The inverted Y is the defining feature. The Colico arm runs north into the Alps and carries the Adda river in and out; the Como arm in the south-west is a closed branch with no outlet, and the Lecco arm in the south-east is where the river leaves. Bellagio stands on the promontory dividing the two southern arms.

Mountains rise directly from the shore, over two thousand metres in the north, so flat ground is scarce and settlements occupy river deltas and ledges. The water mass keeps the climate mild enough for camellias, olives and citrus at the foot of the Alps.

Two daily winds are strong enough to organise activity: the Tivano blows from the north in the morning and the Breva from the south in the afternoon, which is what makes the northern end a serious sailing and windsurfing water.

The lake has a humid subtropical-to-temperate climate, moderated substantially by the volume of water. Summers are warm and humid, generally in the high twenties Celsius, with thunderstorms building over the mountains in the afternoon.

Winters are cool and damp rather than severe — usually two to eight degrees in the day at lake level — with fog and low cloud common. Snow falls on the surrounding peaks far more often than on the shore.

Rainfall is spread through the year and peaks in spring and autumn, which is why the slopes are green and why the gardens work. The practical consequence is that spring arrives early at the water and late a few hundred metres above it.