Bosmarathon 21KM

Bosmarathon 21KM 2025 Course Analysis

Bosmarathon 21KM is a full marathon held in Buggenhout, Belgium, scheduled for Sunday 28 September 2025. The course is run on road surface with 61m of total elevation gain, reaching a maximum altitude of 28m above sea level. For registration and full race details, visit the official Bosmarathon 21KM website.

Elevation Profile

This is a very flat course with only 61m of total elevation gain across the full distance. The course ranges from 10m to 28m above sea level — a 18m elevation range that makes it one of the flatter races available. Runners targeting a personal best will appreciate the minimal climbing.

Expected Race Day Weather

Based on historical weather data for September, the expected race day conditions are as follows. Near-ideal running temperatures are expected, ranging from 5°C to 20°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: Road

Bosmarathon 21KM is run on road surfaces, which provide the fastest and most predictable conditions for marathon running. Road courses allow for consistent pacing and are typically the best choice for runners targeting a personal best time.

How Difficult Is Bosmarathon 21KM?

Our difficulty rating for Bosmarathon 21KM 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 Bosmarathon 21KM against other marathons to find the right race for your goals.