
Washington, United States of America · Saturday 17 October 2026
The Potomac River Run Marathon in October follows an entirely flat, out-and-back course on an unpaved, 12-foot-wide trail adjacent to the Potomac River. Runners travel through a historic landscape marked by 150-year-old canal locks, stone gatehouses, and sections of the Chesapeake & Ohio Canal National Historical Park. The surface consists of packed gravel, with less than 100 meters of deviation onto a wooden footbridge, keeping the majority of the run on a consistent trail.
Adjusted Time
3:51:05
Time difference: -8.9 minutes compared to a flat, road, temperate course.
On our difficulty model, Potomac River Run Marathon (October) plays about 3 minutes faster than an average road marathon for a 3:30 runner. It ranks #1114 hardest of 1150 marathons we analyse, and #553 of 575 in United States of America. Use the calculator above to see the exact adjusted time for your own goal pace.
Estimated finish times on this course versus the same effort on an average road marathon, based on its elevation, surface, and expected race-day temperature.
| Average-course time | On Potomac River Run Marathon (October) | Difference |
|---|---|---|
| 3:00:00 | 2:52:48 | −07:12 |
| 3:30:00 | 3:21:59 | −08:01 |
| 4:00:00 | 3:51:05 | −08:55 |
| 4:30:00 | 4:20:05 | −09:55 |
| 5:00:00 | 4:49:01 | −10:59 |
| 5:30:00 | 5:17:53 | −12:07 |
| 6:00:00 | 5:46:40 | −13:20 |
Use the calculator above for your exact goal time. Want a prediction from your own training? Try the marathon time predictor.
Potomac River Run Marathon (October) is a full marathon held in Washington, United States of America. It is scheduled for Saturday 17 October 2026. The course is run on road surface with 67m of total climbing, with its high point near 35m above sea level. For registration and full race details, visit the official Potomac River Run Marathon (October) website.
This is a very flat course, with only 67m of total climbing and little change in altitude throughout. Flat profiles let you hold an even pace from start to finish, which makes this a fast, PB-friendly race.
Based on historical weather data for October, the expected race day conditions are as follows. Near-ideal running temperatures are expected, ranging from 5°C to 12°C. This temperature range is widely considered optimal for marathon performance, allowing efficient heat dissipation without cold-related issues. There is a high chance of rain (95%). Runners should prepare for wet conditions, including appropriate footwear and clothing choices.
Potomac River Run Marathon (October) is run on road surfaces, which provide the fastest and most predictable conditions for racing. Road courses allow for consistent pacing and are typically the best choice for a personal best.
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