Course
12 km12 km
8 km8 km
Key dates
- ★Race daySat 5 Dec 2026
Date confirmed with the organiser · entry window checked by RunCalendar
About
The Josas Fireflies is a popular running event in France that takes place in the charming town of Jouy-en-Josas. With over 500 runners on the starting line, the event is known for its lively atmosphere, glowing headlamps, and festive spirit. The scenic course offers a mix of terrain, including hills and single-track trails, providing a challenging yet enjoyable experience for participants.
Your next race, seen from above.
Save The Josas Fireflies to your season and RunCalendar reminds you the morning entries open and before they close. Free on iPhone, no account needed.
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Save The Josas Fireflies to your season and RunCalendar reminds you the morning entries open and before they close. Free on iPhone, no account needed.
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