Dirty December Trail Run

Gear up for a festive challenge at the Dirty December Trail Run, returning to the scenic Sycamore Canyon Preserve in San Diego, CA, on December 20, 2026. This "Holiday Trail Fun Run" offers a diverse array of distances to suit every trail runner, including a full Marathon, a Half Marathon, a 10K, and the unique 6-Hour Hill Climb. Runners can expect typical race day conditions with pleasant highs around 66F and lows near 50F, with a minimal 7% chance of precipitation, creating an ideal winter running environment.

The courses promise a rewarding experience across hilly, single-track trails that weave through the beautiful preserve. Marathoners will tackle 26.0 miles with an impressive 4,114 feet of elevation gain, while Half Marathon participants will cover 13.3 miles and ascend 1,921 feet over two clockwise loops. The 10K course, spanning 6.1 miles, features 928 feet of elevation gain, with aid stations strategically placed at roughly 1.2, 4.9, and 6.2 miles to support runners. For those seeking a unique test of endurance, the new 6-Hour Hill Climb dares participants to repeatedly conquer a 2.5-mile route up and down "Cardiac Hill," vying for the coveted "King" or "Queen of the Hill" awards. While the trails offer gorgeous scenery, runners should be mindful of the natural, rough terrain.

Beyond the challenging courses, the Dirty December Trail Run is renowned for its low-key, fun-loving atmosphere, making it a perfect pre-holiday event. It encourages holiday cheer with a costume contest, offering awards for both solo and team festive outfits. With later start times—the marathon beginning at 8:30 AM and other distances at 9:00 AM—runners can enjoy a slightly more relaxed morning before hitting the trails. This event from Dirty Feet Productions, established in 2007, consistently provides a well-organized and memorable trail running experience.