Marathon Eryri (Snowdonia Marathon)
Race Day Weather
Cool start, steady finish
Runners will face a consistent temperature range from 51°F at the start line to 56°F at the finish. With average humidity at 96%, hydration will be crucial throughout the race. Wind gusts reaching 42 mph from the SSW will create challenging conditions, especially with headwinds between miles 7-13. Adjusting pacing strategy for the climbs, particularly from miles 3 to 5 and 23 to 24, will help in maintaining energy.
This course climbs 833 ft to its high point and back, so we forecast it at 2 points, not just the start line. At 9:00/mi, you start at 51° and finish around 2:25 PM in 56°.
Pace Calculator
Enter a finish time to see what race day does to it.
Get forecast alerts for Marathon Eryri (Snowdonia Marathon)
We'll text or email you when the forecast shifts — so you can adjust gear, pacing, and strategy. Max one per day.
Get your personalized Marathon Eryri (Snowdonia Marathon) race plan
A mile-by-mile breakdown of where your time goes, weather-adjusted splits, fueling timeline with aid stations, packing checklist, carb tracker, spectator guide, all built around your goal and race-day conditions.
Race Info
The inaugural Snowdonia Marathon was held in 1982, and was conceived as a dramatic alternative to the numerous city and town races becoming so popular. The demanding and spectacular route, encircling Snowdon, Wales’ and England’s highest peak, has given the event a unique place in the annual marathon calendar ever since. Source
