Date
Sun, 11 Jul 2027
Start
07:00
Venue
Llanberis Event Village/Event Field, beside the Community Centre, Llanberis, LL55 4UR
Llanberis, Gwynedd
Countdown
July
The half is a proper mountain day squeezed into 21 km. 1,250 m of climbing means plenty of walking, so it rewards patient runners.
Key facts
01Minimum age 17
02Compulsory mountain-safety kit
03Cut-offs: 3h25 at 12.5 km, 5h15 to finish
Create a free training plan for the Snowdonia Trail Marathon Eryri 21 km
7-day free trial, no card required
The course
The route
Llanberis
Distance21km
Total climb1,250m
StartElevation
0 kmDrag map to rotate21.2 km
Weather
Mid-July, Llanberis
17°CTypical high
14°CTypical low
11°CColdest in 20 years
55%Days with rain
Highs around 17°C and lows around 14°C, but it has dropped to 11°C. Rain on 55% of days.
NASA POWER data, 2006-2025, the week either side of race day
Results
Course verified. Results not yet available.
Organiser
Training
Training for the Snowdonia Trail Marathon Eryri 21 km
We don't do generic plans. We combine deep knowledge of this race's demands with your recent training, then build a plan with you that progresses as you do.
Beina integrates directly with your existing tools to understand your current fitness, and synchronise your planned sessions.
Intervals.icuWhat a Snowdonia Trail Marathon Eryri 21 km plan targets
Typical sessions
21 km with 1,250 m of climbing
Time on feet and fatigue resistance
Fuelling and pacing for the whole event
What your weeks look like
Typical sessions
Long runs that build time on your feet
Tempo and threshold sessions to hold race pace
Back-to-back weekend runs for fatigue resistance
Not a generic schedule
Typical sessions
Built from your current fitness and the time you actually have
Adapts every week as Beina learns how you respond
Syncs your sessions straight to Garmin and Wahoo
One clear next session, never a wall of spreadsheet
Entries open now
Get your Snowdonia Trail Marathon Eryri 21 km plan.
7-day free trial, no card required.
Other races at Snowdonia Trail Marathon Eryri
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