The weather in Bordeaux is dominated by a maritime climate from the Atlantic Ocean, some 58 kms to the west. The temperature in the region never gets very low, ranging from 9.5°C to 12°C during the winter months. Most of the region's rain comes from cyclonic depressions driving westerly winds off the Atlantic. Average rainfall for the winter period December through March, is 60+ days with heavy rain occurring for 20+ days. In early autumn and late winter, morning fog is quite thick and can hang around for much of the day.
South of Bordeaux, morning frosts can be hazardous to both motorists and vignerons. The driver must be on the lookout for black ice on many roads, while the vignerons are concerned at keeping the frost off their vines. To prevent frost spoiling the harvest, the air is warmed by heaters burning oil, wood or vine clippings which burn very hot.
April, May and June see a change in the weather with temperatures climbing quite quickly from a low of 18°C to a high of 24°C. It can still be damp even during this period with an average 36 days of rain.
From July through August and September, the temperature ranges from a high of 27°C to a low in September of 24°C, which can be uncomfortably hot and sticky in the city. By the coast, there is always the cooling sea breeze, but there is also a risk of a sea mist rolling in to drop the temperatures quite dramatically. It can still be damp even in good years, with an average 20 to 30 days of rain, much of which is a light drizzle rather than the heavier rains of winter.
October and November can be very pleasant months in the Bordelaise. The temperature in October averages 19°C which is pleasant and warm by northern climate standards. November sees the temperature drop to about 15°C and rainfall becomes more frequent with an average 30 rainy days across both months.