Ultra-Trail Snowdonia - Eryri 100K 2027
The forecast arrives five days before the start.
Here you'll find the elevation profile, an estimated finish time based on your UTMB Index and details of the 8 aid stations to plan your nutrition and hydration segment by segment.
What's your time based on your UTMB?
Times estimated by the RAVIT model, learned from real ultra-trail finish times. Enter your UTMB Index (utmb.world) to get a personalized estimate.
Cut-off times and crew - Ultra-Trail Snowdonia - Eryri 100K · 2027
Data from the official race rules, checked for every edition. The race rules prevail. Positions are interpolated along the GPX track and are a guide, not official course marking.
What you'll find at each aid station
| Product | Gwastadannas Farmkm 14.1 | Dolwyddelankm 29.3 | Blaenau Ffestiniogkm 41.8 | Croesorkm 54.1 | Gwastadanas Farmkm 67.5 | Bedgelertkm 81.6 | Rhyd Ddukm 95.9 | Llanberiskm 107.2 |
|---|---|---|---|---|---|---|---|---|
| Water | ✕ | ✕ | ✕ | ✕ | ✕ | ✕ | ✕ | ✕ |
| Brand products · Näak | unavailable | ✕ | ✕ | unavailable | ✕ | unavailable | ✕ | unavailable |
| Hot meal | unavailable | unavailable | unavailable | ✕ | unavailable | ✕ | unavailable | ✕ |
Elevation profile
The course and its aid stations
Ultra-Trail Snowdonia - Eryri 100K: times, aid-station stops and fuelling needs by UTMB® Index
Between a UTMB® Index of 500 and 800, the estimated finish time on this race runs from 24h07 to 13h27, and the aid-station stop budget from 1h22 to 0h25. The longer the race, the more stops weigh: this is time you should plan to spend standing still, not only running.
Below a UTMB® Index of roughly 310, the overall cut-off of 32h30 is no longer reachable at the estimated pace.
| UTMB® Index | Estimated time | Of which stops | Night hours | Carbs | Fluid | Sodium | Cut-off margin |
|---|---|---|---|---|---|---|---|
| 500 | 24h07 | 1h22 | 10.1 | 1,447 g | 16.9 L | 12,054 mg | +8h23 |
| 550 | 22h10 | 1h07 | 8.2 | 1,330 g | 15.5 L | 11,082 mg | +10h20 |
| 600 | 19h52 | 0h54 | 5.9 | 1,192 g | 13.9 L | 9,935 mg | +12h38 |
| 650 | 17h18 | 0h42 | 3.3 | 1,038 g | 12.1 L | 8,651 mg | +15h12 |
| 700 | 15h50 | 0h35 | 1.8 | 950 g | 11.1 L | 7,916 mg | +16h40 |
| 750 | 14h36 | 0h30 | 1.5 | 876 g | 10.2 L | 7,300 mg | +17h54 |
| 800 | 13h27 | 0h25 | 1.5 | 807 g | 9.4 L | 6,722 mg | +19h03 |
Figures based on 60 g of carbohydrate, 700 mL of fluid and 500 mg of sodium per hour, "average" preparation and mild conditions (15–25 °C). Above 25 °C, count on roughly 900 mL/h and 700 mg/h. Carbohydrate intake is trained: 60 g/h is a floor, 90 g/h assumes a glucose-fructose blend and a gut used to it.
Other trails worth preparing for
- Centurion A100158 km · 1,087 m D+ · October 17, 2026
- North Coast 110170 km · 4,705 m D+ · November 7, 2026
- Winter 5588 km · 2,006 m D+ · December 5, 2026
- Arc of Attrition - Arc 100K83 km · 2,588 m D+ · January 23, 2027
- South Downs Way 50M79 km · 1,754 m D+ · April 10, 2027
- Ultra-Trail Snowdonia - Eryri 100M164 km · 9,356 m D+ · May 14, 2027
- Ultra-Trail Snowdonia - Eryri 80K79 km · 2,547 m D+ · May 14, 2027
- Eryri by UTMB® - Eryri 100M®164 km · 9,356 m D+ · May 14, 2027
- Eryri by UTMB® - Eryri 80K®79 km · 2,547 m D+ · May 14, 2027
Sources and method
- Time projection — les temps par cote sont repris des passages réels des coureurs de chaque tranche sur les éditions précédentes de cette course, arrêts aux ravitaillements compris. Aucune formule n'intervient tant que ces résultats existent.
- Trail nutrition — hourly targets for carbohydrate, fluid and sodium follow the commonly accepted ultra-endurance guidance. La Clinique du Coureur — Fuelling in trail running
- Course, aid stations and cut-offs — taken from the event's official rules, which prevail in case of any discrepancy. Official site — Ultra-Trail Snowdonia - Eryri 100K
Weather for Ultra-Trail Snowdonia - Eryri 100K
The weather for Ultra-Trail Snowdonia - Eryri 100K will appear here as soon as the forecast models reach that date, around five days before the start: feels-like temperature, rain, snow, wind and storms, section by section and at your passage time.
Detailed weather for Ultra-Trail Snowdonia - Eryri 100K, hour by hour on the courseFrequently asked questions
How many checkpoints?
Ultra-Trail Snowdonia - Eryri 100K has 8 checkpoints: 7 aid stations and 1 water point. Details are in the two tables above.
What's the longest segment without aid?
The one leading to Dolwyddelan: 15.2 km and 827 m elevation gain. That's the one to load up for first.
How do I find the exact location of an aid station?
The Google Maps icon in the “Access” column opens the aid station's location: handy for planning your crew's routes.
What distance and elevation gain?
Ultra-Trail Snowdonia - Eryri 100K is 107 km long with 5518 m of elevation gain.
How long to finish?
With a UTMB Index of 600 (average runner), the estimated time is around 19h52 for Ultra-Trail Snowdonia - Eryri 100K.
What's the weather forecast?
The weather for Ultra-Trail Snowdonia - Eryri 100K will be published on this page around five days before the start, once the forecast models reach the race date. It will be detailed section by section: feels-like temperature, rain, snow, wind and storms.
Want to stack the odds in your favor for Ultra-Trail Snowdonia - Eryri 100K?
In 2 minutes, RAVIT generates your complete plan: segment-by-segment time, carbs, water and sodium at every aid station, printable roadbook.
No card required · Instant results