2026 Snowdonia Marathon Eryri - Oct 24 Countdown

Q: What is the Snowdonia Marathon Eryri route?

The race starts and finishes just outside Llanberis and makes a full circumnavigation of Yr Wyddfa (Snowdon), the highest peak in Wales and England. From the start it climbs the Llanberis Pass towards Pen-y-Pass, then runs down through Nant Gwynant and out to Beddgelert, on to Rhyd-Ddu and Waunfawr, before a brutal final climb and a steep, rough track descent back into Llanberis. It covers the standard 26.2 miles (42.195 km) entirely around the mountain on closed roads.

Q: How hard is the Snowdonia Marathon and is it the toughest in the UK?

It is widely regarded as one of the hardest road marathons in the UK, with the organisers branding it 'the UK's toughest marathon'. There are three major climbs (Llanberis Pass, out of Beddgelert, and the steep ascent out of Waunfawr near mile 22) totalling roughly 840m of ascent, plus a rough off-road descent to the finish. A New Balance study ranked it among the toughest marathons in Britain. Treat it as a mountain challenge, not a PB attempt.

Q: How much climbing does the Snowdonia Marathon have?

Total ascent is approximately 840m (around 2,750 ft), spread over three substantial climbs. Independent course analyses give a 'flat equivalent' of close to 29 miles of effort. Expect your finish time to be well above your road-marathon average. Plan a realistic effort with our elevation profile tool.

Q: How do I enter the Snowdonia Marathon Eryri 2026?

Entry is by public ballot, which is heavily oversubscribed every year. The ballot typically opens at midday on 1 December and closes at midnight on 8 December, with successful applicants drawn afterwards; unsuccessful entrants are added to a waiting list that is usually offered places. The entry fee is around 50 GBP, and limited charity places are also available. Enter early via the official marathoneryri.com site.

Q: What time does the Snowdonia Marathon start and what is the cut-off?

The marathon starts at 10:30 from just outside Llanberis on Saturday 24 October 2026. There are intermediate cut-off points along the route (for example at the Snowdon Ranger area) and a generous overall limit of around 7 hours, reflecting the difficulty of the course. Check the official Final Instructions, released about 10 days before the race, for the exact cut-off times.

Q: Does the Snowdonia Marathon count for a Boston Qualifier or Good For Age?

Treat it as no. The Snowdonia Marathon is run as a tough mountain road race and there is no confirmed UK Athletics / World Athletics course certification for Boston qualifying (BQ) or a London Marathon Good For Age (GFA) entry, and the brutal terrain makes a qualifying time unlikely anyway. If a BQ is your goal, pick a certified flat course and check the standards with our Good For Age tool.

Q: What is the weather like and how do I get to Llanberis?

Late October in Eryri (Snowdonia) is typically cold, wet and windy, around 11C (52F) at the start with strong gusts on the high passes. Llanberis is a small mountain village with no railway station; most runners drive or take a bus from Bangor or Caernarfon, so arrange parking and travel early as the village fills up on race weekend. Pack mountain layers and waterproofs.

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Race Information

Race	2026 Snowdonia Marathon Eryri - Oct 24
City	Llanberis
Date	2026-10-24 at 10:30
Field Size	~2,800 runners
Time Limit	7 hours
Cutoff pace	9:57/km
Timezone	Europe/London
Official Site	Marathon Eryri
Registration	Register · 50 GBP

Race Day Weather

Average Temperature	11.9°C / 53°F
Humidity	86%
Wind	34.5 km/h
Rain Chance	67%
Typical Conditions	A cold, wet and windy late-October mountain morning in Eryri (Snowdonia). Expect around 11C (52F) at the 10:30 start with high humidity near 86%, strong gusts off the Snowdon massif, and a real chance of rain, mist and exposed wind on the high passes.

What to Prepare: Dress for cold, wet mountain conditions, not a road PB. Bring grippy shoes for the rough descent into Llanberis, a windproof layer, and gloves for the high passes around Pen-y-Pass. The weather can turn fast on Snowdon, so carry more than you think you need.

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 34.5 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	9.6°C	12°C	14.1°C
Dew point	6.3°C	9.9°C	12.6°C

Wet-day chance: 67% Runnability: 62/100

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

Course Profile

Course Type	Closed-road mountain loop circling Snowdon (Yr Wyddfa)
Elevation Gain	840m
Terrain	Road with a steep off-road finishing descent
Profile	Relentlessly hilly with roughly 840m of total climb over three big ascents: a long pull up the Llanberis Pass towards Pen-y-Pass in the first miles, a climb out of Beddgelert near halfway, and a savage final climb out of Waunfawr around mile 22 before a steep, rough track plunges back into Llanberis. This is a tough challenge, not a fast course.

Prepare for 2026 Snowdonia Marathon Eryri - Oct 24

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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Wind Effect on Running — How Much Does Wind Slow You?

How much does a headwind actually slow you down? This free calculator turns wind speed and direction...

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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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Featured In

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Frequently Asked Questions

What is the Snowdonia Marathon Eryri route?

The race starts and finishes just outside Llanberis and makes a full circumnavigation of Yr Wyddfa (Snowdon), the highest peak in Wales and England. From the start it climbs the Llanberis Pass towards Pen-y-Pass, then runs down through Nant Gwynant and out to Beddgelert, on to Rhyd-Ddu and Waunfawr, before a brutal final climb and a steep, rough track descent back into Llanberis. It covers the standard 26.2 miles (42.195 km) entirely around the mountain on closed roads.

How hard is the Snowdonia Marathon and is it the toughest in the UK?

It is widely regarded as one of the hardest road marathons in the UK, with the organisers branding it 'the UK's toughest marathon'. There are three major climbs (Llanberis Pass, out of Beddgelert, and the steep ascent out of Waunfawr near mile 22) totalling roughly 840m of ascent, plus a rough off-road descent to the finish. A New Balance study ranked it among the toughest marathons in Britain. Treat it as a mountain challenge, not a PB attempt.

How much climbing does the Snowdonia Marathon have?

Total ascent is approximately 840m (around 2,750 ft), spread over three substantial climbs. Independent course analyses give a 'flat equivalent' of close to 29 miles of effort. Expect your finish time to be well above your road-marathon average. Plan a realistic effort with our elevation profile tool.

Is the Snowdonia Marathon good for a PB?

No - this is the opposite of a PB course. With ~840m of climbing, exposed mountain weather and a rough finishing descent, most runners finish 20-40 minutes slower than on a flat city marathon. Come for the scenery and the challenge of circling Snowdon, not for a fast time. Use our race time predictor and add a hilly-course buffer.

How do I enter the Snowdonia Marathon Eryri 2026?

Entry is by public ballot, which is heavily oversubscribed every year. The ballot typically opens at midday on 1 December and closes at midnight on 8 December, with successful applicants drawn afterwards; unsuccessful entrants are added to a waiting list that is usually offered places. The entry fee is around 50 GBP, and limited charity places are also available. Enter early via the official marathoneryri.com site.

What time does the Snowdonia Marathon start and what is the cut-off?

The marathon starts at 10:30 from just outside Llanberis on Saturday 24 October 2026. There are intermediate cut-off points along the route (for example at the Snowdon Ranger area) and a generous overall limit of around 7 hours, reflecting the difficulty of the course. Check the official Final Instructions, released about 10 days before the race, for the exact cut-off times.

Does the Snowdonia Marathon count for a Boston Qualifier or Good For Age?

Treat it as no. The Snowdonia Marathon is run as a tough mountain road race and there is no confirmed UK Athletics / World Athletics course certification for Boston qualifying (BQ) or a London Marathon Good For Age (GFA) entry, and the brutal terrain makes a qualifying time unlikely anyway. If a BQ is your goal, pick a certified flat course and check the standards with our Good For Age tool.

What is the weather like and how do I get to Llanberis?

Late October in Eryri (Snowdonia) is typically cold, wet and windy, around 11C (52F) at the start with strong gusts on the high passes. Llanberis is a small mountain village with no railway station; most runners drive or take a bus from Bangor or Caernarfon, so arrange parking and travel early as the village fills up on race weekend. Pack mountain layers and waterproofs.