Cadair X Half Marathon

Cadair X Half Marathon 2026 Course Analysis

Cadair X Half Marathon is a half marathon held in Gwynedd, United Kingdom, scheduled for Saturday 17 October 2026. The course is run on trail surface with 1107m of total elevation gain, reaching a maximum altitude of 886m above sea level. For registration and full race details, visit the official Cadair X Half Marathon website.

Elevation Profile

This is a very challenging course with 1107m of total elevation gain — significantly more than the average trail marathon. The route ranges from 28m to 886m above sea level (858m range). Hill training is essential, and runners should expect a significantly slower time compared to a flat course.

Expected Race Day Weather

Based on historical weather data for October, the expected race day conditions are as follows. Near-ideal running temperatures are expected, ranging from 6°C to 17°C. This temperature range is widely considered optimal for marathon performance, allowing efficient heat dissipation without cold-related issues. There is a low chance of rain (0%), so dry conditions are likely.

Surface Type: Trail

Cadair X Half Marathon is a trail race, meaning the course includes unpaved surfaces such as dirt, gravel, or forest paths. Trail surfaces are inherently slower than road courses due to uneven footing, technical sections, and often steeper gradients. Trail-specific shoes with good grip are recommended, and runners should expect a finish time 10-20% slower than their equivalent road marathon time.

How Difficult Is Cadair X Half Marathon?

Our difficulty rating for Cadair X Half Marathon is calculated using a model that combines elevation gain, temperature impact, and surface type. Use the difficulty calculator above to enter your target finish time and see exactly how many minutes this course would add or subtract compared to a perfectly flat, cool, road-based half marathon. Faster runners and slower runners are affected differently by the same course conditions, so the difficulty is personalised to your pace.

Looking for an easier marathon or a tougher challenge? You can also compare Cadair X Half Marathon against other half marathons to find the right race for your goals.