Barcelona and its metropolitan area has a Subtropical-Mediterranean climate[ (Köppen climate classification: Csa),[ with mild winters and warm summers. According to Troll-Paffen climate classification, Barcelona has a warm-temperate subtropical climate (Warmgemäßigt-subtropisches Zonenklima). According to Siegmund/Frankenberg climate classification, Barcelona has a subtropical climate. Barcelona is located on the eastern coast of the Iberian Peninsula, so Atlantic west winds often arrive in Barcelona with low humidity, producing no rain. The proximity of the Atlantic, its latitude, and the relief, are the reasons why the winters are not so cold and summers are not as dry as in most other Mediterranean Basin locations.
Average annual temperature in Barcelona is 20 °C (68 °F) during the day and 11 °C (52 °F) at night. In the coldest month – January, typically the temperature ranges from 8 to 17 °C (46 to 63 °F) during the day and 2 to 10 °C (36 to 50 °F) at night. In the warmest month – August, the typically temperature ranges from 25 to 31 °C (77 to 88 °F) during the day and about 20 °C (68 °F) at night. Large fluctuations in temperature are rare.
Winters in Barcelona are mild. December, January and February are the coldest months, with average temperatures around 15 °C (58 °F) during the day and 6 °C (42 °F) at night. Slight frost at night is more common on the hills around the city and in the outer metropolitan area (far from the sea). Frost during the day has never been recorded in the city and inner metropolitan area. In winter the average temperature during the day is 10–17 °C (50–63 °F); only on about four days a year does the temperature fall below 10 °C (50 °F).