Black Mountains Marathon

Black Mountains Marathon 2025 Course Analysis

Black Mountains Marathon is a full marathon held in Crickhowell, United Kingdom, scheduled for Saturday 14 June 2025. The course is run on trail surface with 861m of total elevation gain, reaching a maximum altitude of 1594m above sea level. For registration and full race details, visit the official Black Mountains Marathon website.

Elevation Profile

This is a very challenging course with 861m of total elevation gain — significantly more than the average trail marathon. The route ranges from 726m to 1594m above sea level (868m 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 June, the expected race day conditions are as follows. Moderate temperatures between 14°C and 18°C are expected. While comfortable for most runners, those targeting fast times should pay attention to hydration, as these temperatures can impact performance over the full distance. There is a high chance of rain (97%). Runners should prepare for wet conditions, including appropriate footwear and clothing choices.

Surface Type: Trail

Black Mountains 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 Black Mountains Marathon?

Our difficulty rating for Black Mountains 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 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 Black Mountains Marathon against other marathons to find the right race for your goals.