RunThrough Snowdonia Sea2Sky 54k 25k & 12k Trail Races September 2026

Join us for RunThrough Snowdonia Sea2Sky on Saturday 5 September 2026

Take on an all-terrain adventure in the heart of Eryri. RunThrough Snowdonia Sea2Sky serves up big views, honest climbs, and unforgettable miles across rugged Welsh landscapes. From beautiful Barmouth beach to the summit of Cadair Idris and all the way back, this is a route to remember. Choose your challenge and enjoy smooth organisation, clear waymarking, and a finish that feels electric.

Expect a mix of coastal viewpoints, forest tracks, rocky paths, and open mountain trails. Settle into a steady rhythm on the ascents, flow on the descents, and soak up panoramic scenery from start to finish.

Race Distance & Start Times

08:00 - 53k

10:00 - 25k

11:00 - 12k

Included in the entry

Unique themed medal

Free race photos

Chip-timed results

Post-race goodies

All routes will be marked using trail flags and tags, along with A5 arrows and signage. Our friendly marshals will also be on hand to guide you at major junctions and cheer you all the way to the finish. However, please note with all trail races, routes can be disrupted by many things: the weather, disgruntled walkers and wildlife, to name a few! To keep you safe, we provide the GPX for your race route so you can check you’re on track throughout the race and course correct/self-navigate if necessary.

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With RunThrough, you can expect a friendly team of marshals to help guide you around the course and cheer you on to the finish, a lively and well-serviced event village with plenty of food and drink options, including free goodies from our partners at the finish line after your hard effort.

We have been extensively researching what runners consider important, and sustainability is fast becoming the top issue. Click here to see what RunThrough is doing for sustainability.

You can now grab your Snowdonia Sea2Sky event t-shirt for more than 30% off when you buy it as part of your entry on checkout! With the event logo printed on the chest, it’s the perfect keepsake to celebrate your race and wear your achievement with pride!

We can do this with our partner RT Kit as part of a strategic decision to raise awareness about the quality of the product, whilst reducing the overall cost of events for those who would prefer not to have a t-shirt included.

Come and enjoy the day with us. Once you enter, you will receive a confirmation email. More information will be sent closer to the event. We can’t wait to see you on the start line.