Confront one of the UK's most epic and demanding mountain challenges at Ultra-Trail Snowdonia by UTMB, part of the prestigious UTMB® World Series, from May 15-17, 2026. Set in the raw, dramatic landscapes of Snowdonia National Park (Eryri) in North Wales, the event is renowned for its brutally technical terrain and breathtakingly savage beauty, living up to its motto: "Beautiful beyond belief. Savage beyond reason." The flagship race, the UTS 100, is a true mountain ultra featuring over 10,500 meters of ascent and descent, pushing runners to their absolute limits across rugged ridges, scree slopes, and iconic peaks like Tryfan and the Glyderau. With additional distances including a 50-mile, 50km, and a half marathon, the festival offers a formidable challenge for every level of experienced trail and mountain runner, all on meticulously marked courses. As a qualifying event for the UTMB World Series Finals, it attracts a highly competitive international field of over 2,800 runners from more than 60 nationalities, creating a truly global atmosphere at the foot of the Welsh mountains. The organization is world-class, blending the local passion for the trails with the global standards of the UTMB series, ensuring safety, seamless logistics, and an unforgettable finish-line celebration. For runners seeking the ultimate test of mountain endurance, technical skill, and mental fortitude on British soil, Ultra-Trail Snowdonia stands as a definitive, must-do event in the global trail running calendar.
Races Offered
Ultra-Trail Snowdonia by UTMB - UTS 165
May 15, 2026
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Distance —
168K
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-41 days remaining
Ultra-Trail Snowdonia by UTMB - UTS 100
May 16, 2026
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Distance —
104K
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-41 days remaining
Ultra-Trail Snowdonia by UTMB - UTS 50
May 16, 2026
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56K
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-41 days remaining
Ultra-Trail Snowdonia by UTMB - E 25
May 17, 2026
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25K
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-41 days remaining
Weather History
These values represent the 3-year monthly averages for May in Dolwyddelan.
thermostatTemperature
8.4° / 16.1°
wb_sunnyFeels like
6.0° / 13.4°
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Avg sunshine hours
10h 48m
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Avg rainfall
3.4 mm
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Avg snowfall
—
air
Avg wind speed
11.7 km/h (Light breeze)
opacity
Sweat loss rate
Low
terrain
Course conditions
Firm and slightly soft
sunny
Max UV Index
Moderate (4.2)
humidity_mid
Humidity
80.8%
wb_twilight
Sunrise
05:16
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Sunset
21:07
About Dolwyddelan
Learn more about the host city, Dolwyddelan.
Dolwyddelan is a village and community in Conwy County Borough, Wales. The community occupies most of the valley of the Afon Lledr, and contains the settlements of Dolwyddelan, Pentre Bont, Blaenau Dolwyddelan, and Pont-y-Pant. It lies within Snowdonia, and the surrounding hills are part of the Moelwynion range. The population of the community was recorded as 454 in the 2021 census, and in the 2011 census the proportion of Welsh speakers was recorded as 50.8%.
