July is the obvious answer if you want to witness the Fêtes de la Madeleine — the week-long festival centred on the third weekend of July is the defining event of the town's calendar, and there is genuinely nothing else quite like it in the region. Book accommodation months in advance; prices rise sharply and rooms are scarce.
Spring (April–June) and early autumn (September–October) are the best seasons for cycling in the Landes forest: mild temperatures, long days, and the forest at its most pleasant. The town is quiet but open, restaurants are relaxed, and the markets are at their best.
Summer outside festival week is hot — temperatures regularly reach 35°C — and the forest fire risk can close cycling tracks. The town centre is pleasant enough in the early morning and evening, but afternoons are better spent in the shade. The Atlantic coast at Hossegor or Capbreton, about an hour away, offers relief.
Winter in the Landes is mild by northern European standards but damp. Many smaller restaurants reduce their hours. The market continues through the winter, and the town is calm to the point of being sleepy — which suits some travellers perfectly well.