2026 Snowdonia Trail Marathon Eryri - Jul 12 Race Completed

Q: How do you enter the Snowdonia Trail Marathon Eryri?

Entry is open and first-come — no ballot or lottery. You book online through the organiser Always Aim High Events (via EtchRock) until places sell out or entries close on 10 July 2026. Pricing rises in tiers: it started at &pound;57.99 (early) and climbs to &pound;64.99 at the final tier, with the currently-live tier at &pound;61.99. Do not confuse this race with the separate October Marathon Eryri road race, which uses a ballot.

Q: How much climbing does the course have?

The marathon climbs 1,685m (about 5,530ft) of total ascent over 27.3 miles / 44km — it is a deliberate over-distance route, not a standard 26.2. The course encircles and then summits Yr Wyddfa (Snowdon, 1,085m), Wales' highest peak, reaching it via the PyG Track before a long descent of the Llanberis Path. Treat finish-time targets the way you would a fell or skyrace, not a road marathon.

Q: Is the Snowdonia Trail Marathon a Boston qualifier?

No. The course is an uncertified, over-distance mountain trail (27.3mi/44km), so times cannot be submitted as Boston Marathon qualifiers. People run it for the summit and the scenery, not for a BQ. If you need a certified qualifying time, choose a road race with an official measured course instead.

Q: What is the time limit?

The finish-line cutoff is 18:00, giving a 10-hour limit from the 08:30 start. That sounds generous, but with 1,685m of climbing, a high-summit section, and technical descent, a large share of finishers use most of it. There are intermediate cutoffs on the mountain in poor weather — the organiser can shorten or re-route the course on the day for safety.

Q: How hard is the Snowdonia Trail Marathon compared with a road marathon?

Considerably harder. Expect finish times 1.5 to 2.5 hours slower than your road-marathon time because of the relentless climbing, the rocky summit push, and a technical descent that punishes quads. Strong runners can finish in around 4.5-5 hours; many take 7-9 hours. Power-hiking the steep climbs is the right strategy, not a sign of failure.

Q: Is the race ever shortened or affected by weather?

Yes — and it has been. In 2025 the event was weather-shortened: the marathon was re-routed and the ultra stopped due to high winds and poor visibility on the mountain. Snowdon's summit can be in cloud and wind even in July, so the organiser reserves the right to re-route, shorten, or hold runners at safety points. Build flexibility into travel and accommodation plans.

Q: Where is the start and how do I get to Llanberis?

The race starts and finishes in Llanberis, Gwynedd, North Wales — the village at the foot of Snowdon. The nearest large towns are Bangor and Caernarfon; the closest stations are Bangor (national rail, ~20 min by car/bus) and onward by local bus or taxi. Driving, it is roughly 4-4.5 hours from London and under 2 hours from Manchester. Book accommodation in Llanberis or nearby early — the village is small.

Race Completed

This marathon has finished. Check back for next year's edition.

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Race Information

Race	2026 Snowdonia Trail Marathon Eryri - Jul 12
City	Llanberis
Date	2026-07-12 at 08:30
Time Limit	10 hours
Cutoff pace	14:13/km
Timezone	Europe/London
Official Site	Always Aim High Events

Race Day Weather

Average Temperature	15.4°C / 60°F
Humidity	85%
Wind	23.7 km/h
Rain Chance	54%
Typical Conditions	Cool mountain summer with cloud, frequent summit fog, and chance of rain

What to Prepare: Mid-July in Llanberis valley averages a mild ~17°C / 63°F high, but the summit of Yr Wyddfa (1,085m) runs roughly 6-8°C colder and can sit in cloud with wind chill. Mandatory kit (waterproof jacket, hat, gloves) is standard for a reason — pack it even on a clear morning.

Based on historical averages for race week. Use our Weather Score Calculator and What to Wear Guide for personalized advice.

Wind Impact on Race Day

Wind at 23.7 km/h can affect your marathon pace by 5-15 seconds per kilometer. Headwinds slow you down exponentially — a 20 km/h wind costs more than twice a 10 km/h wind.

Calculate your wind-adjusted pace →

Race-Week Climate

Based on 20 years of race-week weather (2005-2024), MERRA-2 reanalysis

	Cooler	Typical	Warmer
Temperature	13.6°C	15.2°C	17.5°C
Dew point	10.4°C	12.7°C	14.7°C

Wet-day chance: 54% Runnability: 68/100

Data: NASA POWER (MERRA-2 reanalysis), NASA Langley Research Center

Course Profile

Course Type	Loop (mountain trail)
Elevation Gain	1685m
Terrain	Mountain trail (rock, scree, grass, some path and track)
Profile	An over-distance mountain trail marathon: 27.3mi / 44km with 1,685m of ascent. The route circles and then climbs Wales' highest peak, Yr Wyddfa (Snowdon), passing Rhyd Ddu, Beddgelert, Nant Gwynant and Pen y Pass before topping out via the PyG Track and descending the Llanberis Path to the finish. Uncertified and over-distance, so it is not a Boston qualifier.

Prepare for 2026 Snowdonia Trail Marathon Eryri - Jul 12

Use our free training tools to get race-ready:

Running Pace Calculator — Min/km, Finish Time & Pace Chart

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Free Pace Band Generator — Printable Race Day Wristband

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Marathon Wake-Up Time Calculator — Race Morning Timeline

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Dew Point Running Calculator — Pace Adjustment Chart

Enter temperature and humidity to calculate dew point and its impact on your running pace. 7-zone ch...

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Elevation Gain/Loss Impact Calculator

How much will hills slow you down? Enter elevation gain, loss, and distance to see adjusted pace, di...

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Grade Adjusted Pace (GAP) Calculator — Hills & Strava

Convert uphill or downhill running pace to flat-equivalent GAP in one click. Free grade adjusted pac...

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Frequently Asked Questions

How do you enter the Snowdonia Trail Marathon Eryri?

Entry is open and first-come — no ballot or lottery. You book online through the organiser Always Aim High Events (via EtchRock) until places sell out or entries close on 10 July 2026. Pricing rises in tiers: it started at £57.99 (early) and climbs to £64.99 at the final tier, with the currently-live tier at £61.99. Do not confuse this race with the separate October Marathon Eryri road race, which uses a ballot.

How much climbing does the course have?

The marathon climbs 1,685m (about 5,530ft) of total ascent over 27.3 miles / 44km — it is a deliberate over-distance route, not a standard 26.2. The course encircles and then summits Yr Wyddfa (Snowdon, 1,085m), Wales' highest peak, reaching it via the PyG Track before a long descent of the Llanberis Path. Treat finish-time targets the way you would a fell or skyrace, not a road marathon.

Is the Snowdonia Trail Marathon a Boston qualifier?

No. The course is an uncertified, over-distance mountain trail (27.3mi/44km), so times cannot be submitted as Boston Marathon qualifiers. People run it for the summit and the scenery, not for a BQ. If you need a certified qualifying time, choose a road race with an official measured course instead.

What is the time limit?

The finish-line cutoff is 18:00, giving a 10-hour limit from the 08:30 start. That sounds generous, but with 1,685m of climbing, a high-summit section, and technical descent, a large share of finishers use most of it. There are intermediate cutoffs on the mountain in poor weather — the organiser can shorten or re-route the course on the day for safety.

What should I wear and carry?

Mountain kit, not road-marathon kit. The organiser enforces mandatory equipment — typically a waterproof jacket with taped seams, hat and gloves, plus a means to carry water and food between the 6 aid/water stations. Trail or fell shoes with real grip are essential for rock and scree. The valley can be 17°C while the summit sits in cold cloud, so layers you can add on the climb matter more than going light.

How hard is the Snowdonia Trail Marathon compared with a road marathon?

Considerably harder. Expect finish times 1.5 to 2.5 hours slower than your road-marathon time because of the relentless climbing, the rocky summit push, and a technical descent that punishes quads. Strong runners can finish in around 4.5-5 hours; many take 7-9 hours. Power-hiking the steep climbs is the right strategy, not a sign of failure.

Is the race ever shortened or affected by weather?

Yes — and it has been. In 2025 the event was weather-shortened: the marathon was re-routed and the ultra stopped due to high winds and poor visibility on the mountain. Snowdon's summit can be in cloud and wind even in July, so the organiser reserves the right to re-route, shorten, or hold runners at safety points. Build flexibility into travel and accommodation plans.

Where is the start and how do I get to Llanberis?

The race starts and finishes in Llanberis, Gwynedd, North Wales — the village at the foot of Snowdon. The nearest large towns are Bangor and Caernarfon; the closest stations are Bangor (national rail, ~20 min by car/bus) and onward by local bus or taxi. Driving, it is roughly 4-4.5 hours from London and under 2 hours from Manchester. Book accommodation in Llanberis or nearby early — the village is small.