Winters in Aosta are typically cold, with temperatures often dropping below freezing point in January and December, averaging around -1°C. Spring brings a gradual warming, with April being the first month to consistently reach above 0°C, averaging 9°C. Summer months of June, July, and August are warm, with average highs ranging from 19-20°C, but temperatures can still drop to near-freezing at night. Autumn is mild, with October temperatures averaging around 10°C before a slight cooling in November.