Biarritz's weather is characterized by mild winters and warm summers. January and February are cool, with temperatures ranging from around freezing to the mid-teens, while March and April bring a gradual warming trend, with temperatures often reaching the late 20s. May and June mark the beginning of summer, with temperatures rising into the high teens to low thirties. July and August are the warmest months, with temperatures in the mid-twenties to early thirties, while September brings a slight cooling trend before autumn takes hold. As winter returns in November and December, temperatures drop again, though rarely below freezing.