Bordeaux's climate is usually classified as an oceanic climate (Köppen climate classification Cfb); however, the summers tend to be warmer and the winters milder than most areas of similar classification. Substantial summer rainfall prevents its climate from being classified as Mediterranean.
Winters are mild because of the prevalence of westerly winds from the Atlantic. Summers are warm and long due to the influence from the Bay of Biscay (surface temperature reaches 21 to 22 °C (70 to 72 °F). The average seasonal winter temperature is 6.53 °C (43.75 °F), but recent winters have been warmer than this. Frosts in the winter are commonplace, occurring several times during a winter, but snowfall is very rare, occurring only once every three years. The average summer seasonal temperature is 19.51 °C (67.12 °F), but every summer in the decade beginning 2001 has exceeded this average. The summer of 2003 set a record with an average temperature of 23.3 °C (73.9 °F)
