Fox Valley Marathon

Fox Valley Marathon 2026 Course Analysis

Fox Valley Marathon is a full marathon held in St. Charles, United States of America, scheduled for Sunday 20 September 2026. The course is run on road surface with 0m of total elevation gain, reaching a maximum altitude of 223m above sea level. For registration and full race details, visit the official Fox Valley Marathon website.

Elevation Profile

This is a very flat course with only 0m of total elevation gain across the full distance. The course ranges from 192m to 223m above sea level — a 31m 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. Hot conditions are expected, with temperatures between 18°C and 32°C. Heat is one of the biggest performance factors in marathon running — research shows that for every degree above 15°C, marathon times slow by approximately 1-2%. Extra hydration and a conservative start are strongly recommended. There is a high chance of rain (60%). Runners should prepare for wet conditions, including appropriate footwear and clothing choices.

Surface Type: Road

Fox Valley 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 Fox Valley Marathon?

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