Les Lucioles du Josas 2026

Les Lucioles du Josas is a December night race held in Jouy-en-Josas, in the Yvelines department west of Paris. It takes place around the town’s Christmas market. Participants can choose between an 8 km or a 12 km route; the longer route features approximately 350 metres of elevation gain. This is a costumed, untimed event, creating an atmosphere more akin to a festive trail run than a typical road race, despite the route demanding genuine effort. The course combines town streets with ascents, stairs, mud, fog, and unique small passages that lend it an adventurous character rather than a straightforward loop. Runners will pass the Christmas market and the illuminated streets of Jouy-en-Josas. Mulled wine, costumes, and occasional snow enhance the December ambiance. Les PassePartout Trailers du Josas organize the race, with volunteers assisting in welcoming and guiding participants. Awards are given to both the fastest finishers and the best male and female costumes.