Het weer in Biarritz in mei

May in San Sebastian is the unstable month - June is the reliable one, and late May is where it starts to settle. Regulars will tell you it can be 30C and sunny or 14C and raining, sunny in the morning and pouring by afternoon, and they quote the Spanish line about not taking your coat off until the fortieth of May. The local word for the default is sirimiri, the fine constant Basque drizzle that is neither shower nor storm; our row's 116mm across 12.7 precipitation days is mostly that. Their packing answer is layers, waterproofs and a swimming costume anyway. The record: 19.6C days, 13C nights, humidity 80 percent, 10.7 hours of sun and a 16.9C sea.

Forum posters describe January in Biarritz as similar to December, cold around 10-12C and potentially wet and windy, though posters note there's usually at least a day or two of notably milder weather within any given winter stretch. Posters are direct that winter here is actually the driest season overall, with long, dry, sunny spells a genuine feature of the Basque coast's mild oceanic climate, even as a visitor could just as easily get lucky with 15-17C days or unlucky with persistent driving rain off the Atlantic. Posters consistently describe Biarritz as very much a summer tourist town, but note the roughly 40,000 year-round residents and a university in nearby Bayonne keep plenty of restaurants and shops open through the quieter winter months. Posters generally rate January as cool, changeable but genuinely livable, with real chances of both pleasant and rough weather days.

June to August is Biarritz's best weather and its high season together. July averages near 24°C, and the sea is warm enough that the forum says you can often surf in shorts by mid-month, with some days not needing a wetsuit at all — they put the water at 20–21°C, the record a little higher. The honest caveat is that the weather is temperamental: a couple of really nice days, then rain, then a couple more, with afternoon thunderstorms in the mix, against seven wet days on the record. The rocky coastline is the surf advantage here — the breaks vary with the wind, so something is usually working.