Great Welsh Marathon

Carmarthenshire, Wales, UK · October 17, 2027

54°·57° high·Breezy·Dry

Weather

Race Day Weather

54°at start

58° high

Breezy

Dry

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Cool and breezy, slight humidity

Runners will face a starting temperature of 54°F, gradually rising to 58°F. Winds will be from the SSW at 14 mph, with gusts up to 24 mph, creating a headwind throughout. With humidity at 77%, a conservative pace is advised, especially in the early miles.

Race day forecast available in 336 days

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Distance: 26.2mi

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Race Info

The Great Welsh Marathon moves to Swansea for its 2027 edition on Sunday 17 October 2027, after more than ten years in Carmarthenshire. The 26.2-mile course is planned as a single loop that starts and finishes in the city and runs along Swansea Bay, with the full route due to be announced in November 2026. It is organised by Front Runner Events and targets 7,500 runners. Source

Website

Race weekend

Sunday, October 17

9:00 AMMarathon (26.2 mi)

Half Marathon (13.1 mi)

Course Map

FAQ

When is the 2027 Great Welsh Marathon?

The 2027 Great Welsh Marathon will be held on Sunday October 17, 2027.

Is the Great Welsh Marathon a Boston Marathon Qualifier?

Yes, the Great Welsh Marathon is an official Boston Marathon qualifier.

What will the weather be like for the 2027 Great Welsh Marathon?

The forecast calls for a high of 58°F and a low of 53°F with a 16% chance of rain.

Historical Weather

Based on 7 years of data

Avg Temp

50°F

L:47° H:52°

RunScore

Conditions

Rain Freq

43%

3 of 7 yrs

Wind13mph

Dew42°F

Temperature History

Range of temperatures during race hours for each year.

Detailed History

Year	Low / High	Rain	Dew Point
2026 Great Welsh Marathon Partly cloudy throughout the day with rain in the morning and afternoon. 2026	48°/49°	Light	47°
2025 Great Welsh Marathon Becoming cloudy in the afternoon. 2025	38°/50°	-	34°
2024 Great Welsh Marathon Partly cloudy throughout the day with rain clearing later. 2024	50°/52°	Light	50°
2022 Great Welsh Marathon Partly cloudy throughout the day. 2022	50°/58°	-	42°
2019 Great Welsh Marathon Partly cloudy throughout the day. 2019	41°/46°	-	29°
2018 Great Welsh Marathon Partly cloudy throughout the day with rain. 2018	50°/54°	Light	49°
2017 Great Welsh Marathon Partly cloudy throughout the day. 2017	54°/56°	-	46°