Genoa has a borderline humid subtropical (Cfa) and Mediterranean climate (Csa), since only one summer month has less than 40 millimetres (1.6 in) of rainfall, preventing it from being classified as solely humid subtropical or Mediterranean.
The average yearly temperature is around 19 °C (66 °F) during the day and 13 °C (55 °F) at night. In the coldest months: December, January and February, the average temperature is 12 °C (54 °F) during the day and 6 °C (43 °F) at night. In the warmest month – July and August – the average temperature is 27.5 °C (81 °F) during the day and 21 °C (70 °F) at night. Generally – summer's/holiday season lasts about 4 to 6 months, from May/June to September/October. The daily temperature range is limited, with an average range of about 6 °C (43 °F) between high and low temperatures.
In the during the day never recorded a temperature below zero. Annually, the average 2.9 of nights recorded temperatures of ≤0 °C (32 °F) (mainly in January). The coldest temperature ever recorded was −6.8 °C (20 °F) on the night of January 1985; the highest temperature ever recorded during the day is 35.4 °C (96 °F) on the July 1971 and August 1990. Average annual number of days with temperatures of ≥30 °C (86 °F) is about 8, average four days in July and August.
Average annual temperature of the sea is 17.5 °C (63 °F), from 13 °C (55 °F) in the period January–March to 25 °C (77 °F) in August. In the period from June to October, the average sea temperature exceeds 19 °C (66 °F).
Genoa is also a windy city, especially during winter when northern winds often bring cool air from the Po Valley (usually accompanied by lower temperatures, high pressure and clear skies). Another typical wind blows from southeast, mostly as a consequence of atlantic disturbances and storms, bringing humid and warmer air from the sea. Snowfall is sporadic, but does occur once or twice per year.
Annual
