Boulderthon - Boulder Marathon

Boulderthon - Boulder Marathon 2026 Course Analysis

Boulderthon - Boulder Marathon is a full marathon held in Boulder, United States of America, scheduled for Sunday 27 September 2026. The course is run on road surface with 255m of total elevation gain, reaching a maximum altitude of 1648m above sea level. For registration and full race details, visit the official Boulderthon - Boulder Marathon website.

Elevation Profile

With 255m of elevation gain, this is a moderately undulating course. The route ranges from 1557m to 1648m above sea level (91m total range). While not completely flat, the elevation changes are manageable for most runners and shouldn't significantly impact pacing strategy.

Expected Race Day Weather

Based on historical weather data for September, the expected race day conditions are as follows. Moderate temperatures between 12°C and 26°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 low chance of rain (12%), so dry conditions are likely.

Surface Type: Road

Boulderthon - Boulder Marathon 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 Boulderthon - Boulder Marathon?

Our difficulty rating for Boulderthon - Boulder 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 Boulderthon - Boulder Marathon against other marathons to find the right race for your goals.