2027 Great Welsh Marathon - Oct 17 Countdown

Q: Where is the Great Welsh Marathon and what is the route?

The Great Welsh Marathon is held in Carmarthenshire on the South Wales coast, near Llanelli. Recent editions started and finished at Pembrey Country Park and ran out along the Millennium Coastal Path with views over the Loughor Estuary and the Gower Peninsula. For 2027 the event is moving to a brand-new course elsewhere in Carmarthenshire — the organisers say it is designed to be even flatter and faster, with the exact route confirmed closer to race day.

Q: When is the Great Welsh Marathon 2027 and what time does it start?

The 2027 race is on Sunday 17 October 2027. The full marathon starts at 09:00, with the half marathon setting off shortly afterwards. Note that the event has moved from its traditional March/spring date to autumn for 2027, so it now sits in the busy October marathon window.

Q: What is the cut-off time for the Great Welsh Marathon?

The full marathon has a 6-hour time limit (the half marathon allows 4 hours). That works out to roughly a 13:45 min/mile or 8:30 min/km average for the marathon. The flat course and generous cut-off make it realistic for first-timers, but confirm the latest course-closure details on the official site before entering. Use our finish time calculator to check you are comfortably inside the limit.

Q: How do I enter the Great Welsh Marathon 2027 and how much does it cost?

Entry is open to the public on a first-come basis (no ballot) through the official site at greatwelshmarathon.co.uk. The full marathon costs around GBP 50 for unaffiliated runners and GBP 48 for affiliated runners, with early-bird pricing typically a little lower. The race is organised by Front Runner Events. Race packs are posted out roughly two weeks before race day, so there is no same-day registration.

Q: Does a Great Welsh Marathon time count for Boston qualifying or a London Good For Age place?

Yes. The event is an AIMS member and is marketed as a World Marathon Majors Qualifier, so a time run on the accurately measured course is valid for Boston qualifying (BQ) and a London Marathon Good For Age (GFA) entry. There is no qualifying standard to enter — your finish time simply counts. Check your target against the standards with our Good For Age tool.

Q: What should I wear and how do I get to the Great Welsh Marathon?

Mid-October on the South Wales coast is cool, breezy and often wet — around 11C (52F) at the start, with a real chance of showers and a coastal wind. Race in your usual long-run kit with a thin throwaway top for the start and a cap; pack a light waterproof. The race area sits near Llanelli in Carmarthenshire, reachable by car (parking on site, charges apply) or by train to Llanelli or Pembrey &amp; Burry Port stations. Arrive early, as parking and roads get busy before the 09:00 start.

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Race Information

Race	2027 Great Welsh Marathon - Oct 17
City	Llanelli
Date	2027-10-17 at 09:00
Time Limit	6 hours
Cutoff pace	8:32/km
Timezone	Europe/London
Official Site	Front Runner Events Ltd (Great Welsh Marathon)
Registration	Register · 50 GBP

Race Day Weather

Average Temperature	13.2°C / 56°F
Humidity	86%
Wind	30.2 km/h
Rain Chance	56%
Typical Conditions	Cool, breezy and often wet mid-October morning on the South Wales coast. Expect around 11C (52F) at the 09:00 start, climbing into the low-to-mid teens, with high humidity, a stiff coastal wind off the estuary and a good chance of showers — October is one of the wettest months here.

What to Prepare: Dress for low-double-digit Celsius and wind rather than warmth: a cap, a thin throwaway layer for the start and a light waterproof in your bag. The flat course is kind to a PB, but plan for the headwind on any out-and-back stretch and pace the early miles conservatively.

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 30.2 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	11.1°C	13.2°C	15.1°C
Dew point	7.6°C	10.7°C	13.8°C

Wet-day chance: 56% Runnability: 66/100

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

Course Profile

Course Type	Flat road course, fully signed and supported, coastal Wales
Elevation Gain	110m
Terrain	Road and surfaced coastal path
Profile	The organisers market the Great Welsh as one of the flattest, fastest marathons in the UK. Its established Pembrey course had only modest total climb of roughly 110m and a maximum elevation around 18m; for 2027 the event moves to a brand-new course elsewhere in Carmarthenshire (exact route confirmed closer to race day), again aimed at first-timers and PB chasers.
Boston Qualifier	Yes — Check your BQ time

Prepare for 2027 Great Welsh Marathon - Oct 17

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

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

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Marathon Predictor — 5K, 10K & Half Marathon Race Predictor

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Featured In

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Frequently Asked Questions

Where is the Great Welsh Marathon and what is the route?

The Great Welsh Marathon is held in Carmarthenshire on the South Wales coast, near Llanelli. Recent editions started and finished at Pembrey Country Park and ran out along the Millennium Coastal Path with views over the Loughor Estuary and the Gower Peninsula. For 2027 the event is moving to a brand-new course elsewhere in Carmarthenshire — the organisers say it is designed to be even flatter and faster, with the exact route confirmed closer to race day.

Is the Great Welsh Marathon flat and good for a PB?

Yes — this is one of its main selling points. The organisers describe it as one of the flattest marathons in the UK, with total elevation gain of only about 110m and a high point around 18m on the established course. The flat, scenic profile makes it a popular choice for first marathons and personal bests. Plan your target with our pace calculator and check the climbs against your goal pace with the elevation profile tool.

When is the Great Welsh Marathon 2027 and what time does it start?

The 2027 race is on Sunday 17 October 2027. The full marathon starts at 09:00, with the half marathon setting off shortly afterwards. Note that the event has moved from its traditional March/spring date to autumn for 2027, so it now sits in the busy October marathon window.

What is the cut-off time for the Great Welsh Marathon?

The full marathon has a 6-hour time limit (the half marathon allows 4 hours). That works out to roughly a 13:45 min/mile or 8:30 min/km average for the marathon. The flat course and generous cut-off make it realistic for first-timers, but confirm the latest course-closure details on the official site before entering. Use our finish time calculator to check you are comfortably inside the limit.

How do I enter the Great Welsh Marathon 2027 and how much does it cost?

Entry is open to the public on a first-come basis (no ballot) through the official site at greatwelshmarathon.co.uk. The full marathon costs around GBP 50 for unaffiliated runners and GBP 48 for affiliated runners, with early-bird pricing typically a little lower. The race is organised by Front Runner Events. Race packs are posted out roughly two weeks before race day, so there is no same-day registration.

Does a Great Welsh Marathon time count for Boston qualifying or a London Good For Age place?

Yes. The event is an AIMS member and is marketed as a World Marathon Majors Qualifier, so a time run on the accurately measured course is valid for Boston qualifying (BQ) and a London Marathon Good For Age (GFA) entry. There is no qualifying standard to enter — your finish time simply counts. Check your target against the standards with our Good For Age tool.

What should I wear and how do I get to the Great Welsh Marathon?

Mid-October on the South Wales coast is cool, breezy and often wet — around 11C (52F) at the start, with a real chance of showers and a coastal wind. Race in your usual long-run kit with a thin throwaway top for the start and a cap; pack a light waterproof. The race area sits near Llanelli in Carmarthenshire, reachable by car (parking on site, charges apply) or by train to Llanelli or Pembrey & Burry Port stations. Arrive early, as parking and roads get busy before the 09:00 start.