Great Welsh Marathon
Race Day Weather
Cool start, moderate wind challenge
Runners will face a steady temperature trend from 54°F to 58°F. With winds from the SW reaching 14 mph, pacing adjustments may be necessary to counter the headwind. The 77% humidity suggests a need for increased hydration, especially as temps rise slightly during the race.
Pace Calculator
Get forecast alerts for Great Welsh Marathon
We'll text or email you when the forecast shifts — so you can adjust gear, pacing, and strategy. Max one per day.
Race Info
Hosted at the magnificent Pembrey Country Park in Carmarthenshire this race showcases the best of coast and country on a route that covers both the half and full marathon distance. This is a race for everyone, so whether you love inspiring green spaces or are a sucker for coastal views, then you’ll run happy, as this has it all! Boasting a maximum elevation of only 18 metres and an overall gain of 110 metres for the full marathon distance, this race offers a superb opportunity to achieve your personal best! It’s the perfect spring race that is flat, friendly, and great for first-timers or PB chasers! Source
Historical Weather
Temperature History
Range of temperatures during race hours for each year.
Detailed History
| Year | Conditions | Low / High | Rain | Dew Point | Score |
|---|---|---|---|---|---|
2026 | | 48°/50° | Light | 48° | |
2025 |  | 38°/50° | - | 33° | |
2024 |  | 50°/54° | Light | 50° | |
2022 | | 50°/58° | - | 43° | |
2019 |  | 41°/50° | - | 30° | |
2018 | | 50°/54° | Light | 49° | |
2017 | | 54°/57° | - | 47° |