According to the Köppen climate classification, Como has a humid subtropical climate (Cfa); winters are not long, but foggy, damp and chilly with occasional periods of frost from the siberian anticyclone; spring and autumn are well marked and pleasant, while summer can be quite oppressive, hot and humid. Wind is quite rare; only sudden bursts of foehn or thunderstorms manage to sweep the air clean. Pollution levels rise significantly in winter when cold air clings to the soil. Rain is more frequent during spring; summer is subject to thunderstorms and, occasionally, violent hailstorms
