DateExpected
Early September 2027
Based on past editions. We'll confirm when the organiser announces.
Venue
Bath House Beach, Barmouth, Wales
Barmouth, Gwynedd
Countdown
September
The middle distance at Sea2Sky. 25 km with only 739 m of climbing, so a runnable day out for anyone stepping up from a 10K or half.
Key facts
01Minimum age 17
Create a free training plan for the Snowdonia Sea2Sky 25 km
7-day free trial, no card required
The course
The route
Barmouth
Distance25km
Total climb739m
StartElevation
0 kmDrag map to rotate25.5 km
Weather
Early-September, Barmouth
17°CTypical high
10°CTypical low
5°CColdest in 20 years
57%Days with rain
Highs around 17°C and lows around 10°C, but it has dropped to 5°C. Rain on 57% of days.
NASA POWER data, 2006-2025, the week either side of race day
2025 results
Who finishes, and how
#RiderTimeAvg speed
01Naomi EATON02:22:4610.5 km/h
02Aušra PILITAUSKAITE02:24:4110.4 km/h
03Kerri WILLIAMS02:33:069.8 km/h
219
Women finishers
3:44:39
Median time
6.7 km/h
Median speed
Women · 2025 results, as published by the organiser.
How fast could you finish?
Get a prediction based on your recent training
Organiser
OrganiserRunThrough Trails (RunThrough)
Websiterunthroughtrails.com
Instagram@runthroughtrails
Running since2024
Training
Training for the Snowdonia Sea2Sky 25 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 Sea2Sky 25 km plan targets
Typical sessions
25 km with 739 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 Sea2Sky 25 km plan.
7-day free trial, no card required.
Other races at Snowdonia Sea2Sky
More events in September in United Kingdom
Borders 8-hour ChallengeExpected Early September 2027 · Newcastleton→Dartmoor in a DayExpected Early September 2027 · Okehampton→Highland Perthshire ChallengeExpected Early September 2027 · Scone→The Bà SportiveExpected Early September 2027 · Kinlochewe→Cross Border SportiveSun, 5 Sept 2027 · Brampton→ExterminatorSun, 5 Sept 2027 · Sheffield→
