Ubonratchathani 100K Ultra Marathon 2026

Ubonratchathani 100K Ultra Marathon 2026 is an overnight loop ultra at Huai Muang Public Park in Ubon Ratchathani, Thailand, on 5-6 December. The race uses a 2.3 km park circuit, creating a controlled endurance format with repeated access to the central support area while still demanding disciplined pacing through the night.

The 100K Solo starts at 15:00 on Saturday 5 December and has an 18-hour limit, finishing by 09:00 on Sunday after 44 laps. The 50K Solo starts at 20:00 and has a 10-hour limit, with 22 laps and a 06:00 Sunday cut-off. A mixed four-person 100K relay starts alongside the solo 100K at 15:00. Relay teams complete the same 44-lap total, with each runner covering 11 laps and at least one woman required in each team.

Published regular entry fees were THB 1,900 for the 100K Solo, THB 1,500 for the 50K Solo and THB 4,800 per relay team. Earlier early-bird rates were THB 1,700, THB 1,200 and THB 4,000 respectively. Registration is now closed.

Race bib collection takes place at Huai Muang Public Park beside the basketball court on 5 December. The 100K Solo and relay categories collect from 09:00 to 14:00, while 50K runners can collect from 09:00 to 19:00. Collection must be in person with identification and proxy collection is not permitted.

Published runner support includes chip timing, race and finisher shirts, finisher medals and e-certificates, a commemorative bag, water, electrolyte drink, fruit and snacks, three scheduled meal services at the central station, medical assistance and accident insurance. The top three men and women in the solo races receive trophies and cash prizes, while places four to ten receive trophies; the relay also awards cash and trophies to the top three teams.