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entries openGB Ultras
Yr Wyddfa Ultra 100
GB Ultras 100 Mile Series
Next edition: Saturday, 5 September 2026 – Monday, 7 September 2026Betws-y-Coed, Wales
A self-navigated 100-mile mountain race through Eryri, combining a high-level route, severe-weather alternative, eleven checkpoints and sustained overnight exposure.
Official race site (opens in a new tab)
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Distance102 mi
Ascent5,172m
Climb / km31.5m
Cutoff42h
Cutoff pace15:21/km
Technicality9/10
Entry£209
FormatLooped
Next edition
5 September 2026 – 7 September 2026
This is the most relevant confirmed edition currently held for the permanent race family. Edition-specific facts should still be checked against the final organiser instructions.
Edition archive
Expand an edition to inspect its year-specific facts. Other years never replace the primary edition facts.
Other announced editions
2027 to Upcoming
These facts belong to the 2027 edition only. Missing values have not been copied from another year.
- Distance
- 160.93 km
- Ascent
- Not verified
- Cutoff
- Not published
- Entry
- Not verified
- Format
- continuous · single stage · looped
- Stage layout
- Not applicable
Successful source check: 1 Sept 2026Source confidence: highThe official GB Ultras calendar confirms Yr Wyddfa Ultra 100 Mile for 4 September 2027. No 2027-specific elevation, cutoff, fee, field, checkpoint or route values are copied from the conflicted 2026 sources.
Check Yr Wyddfa Ultra 100 2027 source (opens in a new tab)
Race For You difficulty
7.1/ 10
Very hard
High evidence confidence · 84% evidence coverage
This score is driven most by substantial race distance, high climbing demand, technical terrain. Difficulty V2's separate time-limit modifier adds 0.00 points here and is capped at 0.70; a broad limit cannot erase extreme intrinsic demand. This is independent of the public Cutoff Pressure V2 band.
Weather, conditions and individual preparation can change the real difficulty significantly.
How the score works Distance, weighted 30 percent6.9 out of 10
Climbing, weighted 25 percent6.3 out of 10
Technicality, weighted 15 percent9 out of 10
Accumulated burden, weighted 17 percent5.7 out of 10
Exposure & support, weighted 13 percent7.5 out of 10
Course analysis
What shapes this race
Expect sustained upland ground and meaningful climbing, sections where foot placement and downhill confidence matter, forest trail that may change character in wet conditions.
trailmountainforesttechnical
Climbing density
31.5m per km
A more useful comparison than total ascent alone: it shows how consistently the course asks you to climb.
Cutoff analysis
Moderate pressure
To finish inside 42h, the raw average required is 15:21 per kilometre (24:43 per mile), including every stop.
Raw pace15:21/km
PressureModerate pressure
Cutoff pressure compares the published time limit with distance, ascent and verified course demands. Lower pressure does not mean the race is easy. Raw pace includes checkpoints, food stops, navigation errors and any sleep; it is not a pacing plan.
Who this suits
First ultra?
This is not designed as a first-ultra recommendation. Significant endurance, navigation or mountain-race experience is strongly advised.
1.2/10 suitability
Navigation
self-navigation
Route-finding is part of the challenge. Carry the required mapping tools and be able to use them in darkness and poor visibility.
Exposure & kit
extensive kit
Significant overnight running is likely for many entrants. Lighting, temperature management and sleep strategy can materially affect the outcome.
Personal race predictor
Will you make the cutoff?
Use a previous result to estimate a realistic range for Yr Wyddfa Ultra 100, your potential buffer and the biggest change in demand.
Practical detail
Support & logistics
Aid stations11 listed
Support levelaid stations
LogisticsParking noted
LogisticsAccommodation nearby
LogisticsBag drop
LogisticsCrew access
Logistics are only shown where currently recorded. Confirm parking, transport, crew access and final aid-station plans with the organiser.
Latest verification
Trust the source, see the gaps.
Data HighThe official event-page vital statistics list 102 miles, 5,172m, a 42-hour cutoff, £209 and 150 places for 5 September 2026, and its route copy confirms self-navigation and eleven checkpoints. The series listing instead says 5,788m and 40 hours; the event-page values are retained with Medium confidence and the conflict is explicit.
- Successful source check
- 3 Sept 2026
- Catalogue record updated
- 3 Sept 2026
- Official source
- Available
Official source 1 (opens in a new tab)Official source 2 (opens in a new tab)Official source 3 (opens in a new tab)
Event details can change after a successful source check. Confirm the final route, kit, cutoff, price and entry terms directly with the organiser before entering or travelling.
Found something wrong?
Help keep this race accurate.
Wrong cutoff? Date changed? New course? Tell us what moved and include the official source if you have it.
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