Snowdonia Trail Marathon Eryri Returns in July 2027

We can now confirm the return of the Snowdonia Trail Marathon Eryri for 2027, with four distances taking place across a full weekend of trail running in the spectacular landscapes of Eryri.

The event will take place on Saturday 10th and Sunday 11th July 2027, continuing a tradition that has seen the event held at this time of year for more than a decade.

The 10K will take place on Saturday 10th July, followed by the Half Marathon, Marathon and Ultra Marathon on Sunday 11th July, giving runners of a wide range of abilities the opportunity to experience one of the UK's most spectacular trail running locations.

Remaining on the traditional July weekend

The 2027 date follows two challenging editions of the event, both of which were significantly affected by exceptionally hot weather.

Despite those experiences, we have made the decision to retain the event's established July weekend. The Snowdonia Trail Marathon Eryri has taken place at this time of year for more than a decade, with successful editions held before the challenges of the past two years.

The conditions experienced at the 2026 were exceptional, with other outdoor events in the surrounding area taking place successfully both the weekend before and the weekend after without experiencing the same extreme heat.

While weather will always be a factor when organising an event in a mountain environment, the experiences of the past two years have provided important lessons and an opportunity to review how the event can be made more resilient.

New courses for 2027

As part of that review, changes are being made to the Snowdonia Trail Marathon Eryri courses for 2027.

The revised routes have been designed so that more of the significant ascent is tackled earlier in the race. This will give the event team greater flexibility to manage the course effectively should challenging conditions develop as the day progresses.

Should we experience unusually high temperatures again, the revised course layouts will give us more options to adapt the event and reduce participants’ exposure to the most demanding sections of the course during the hottest part of the day.

The races will also start much earlier in the morning, allowing participants to complete more of the course during the cooler part of the day.

The changes form part of wider event planning for 2027, with participant safety remaining at the heart of decision-making.

While it is impossible to completely remove the potential impact of weather from a mountain event, the aim is to use everything learned from the past two years to make the event as adaptable and resilient as possible.

The new routes still deliver everything that makes Snowdonia Trail Marathon Eryri special: spectacular trails, challenging mountain terrain and an unforgettable journey through the heart of Eryri.

Entries for the 2027 Snowdonia Trail Marathon are now open! Explore the new routes and secure your place using the links below.