Diablo Summit Stomp 2026

The Diablo Summit Stomp 2026 returns to Walnut Creek in California on October 17th. The event offers a variety of distances including the 5K, Half Marathon, 30K, and Remote Runner, each starting from trails that are firm yet slightly soft.
On race morning, runners will find themselves surrounded by the natural beauty of the Diablo range. Typically in early October, temperatures average around 19.5°C with a comfortable humidity level of 61.5%, making for pleasant conditions as you begin your journey through the park's winding trails and scenic overlooks. The course offers a mix of terrain, from gentle ascents to more challenging sections, but Brazen Racing ensures it remains accessible to both first-time trail runners and seasoned athletes.
The Diablo Summit Stomp 10K, Half Marathon, 30K, 5K, and Remote Runner have been running for several years now. The event attracts a diverse group of participants from the local community, with age group awards recognizing top finishers in five-year categories down to younger runners. This race is significant because it supports scholarships for Walnut Creek High School students, fostering both physical activity and educational opportunities.
The course venue takes you through rugged trails that are firm yet slightly soft underfoot, providing a unique challenge on this day. The start and finish will be at the Walnut Creek Community Park, where elevation gains of modest hills offer scenic views along the way. There won't be any aid stations during the race but runners can rely on their energy gels or water bottles for hydration.
Weather conditions in October are generally mild with an average high temperature around 25.2°C and a minimum of 13.7°C, creating comfortable racing weather that feels just right at 19.5°C when you're out there running. The humidity is typical at 61.5%, which keeps the air from feeling heavy despite some light winds at an average speed of 8.2 km/h.

The race offers a 10K, Half Marathon (30km), 5K (5km) and Remote Runner distance options with fees ranging from $71.64 to $116.47 respectively.
Register at https://raceroster.com/events/2026/114667/diablo-summit-stomp-2026 by the deadline for your chosen race and pay the required fee online. Bib pickup will be on October 15th from 3 to 8 PM at Walnut Creek Community Park, where you'll need to bring a photo ID.
The start location is Walnut Creek Community Park in Walnut Creek, California. Race day requires participants to be 16 years old or older (exceptions for the Remote Runner category). First-timers should arrive prepared with appropriate running gear and shoes suitable for trail conditions.
The Diablo Summit Stomp 2026 stands out as a community event that supports scholarships at Walnut Creek High School, making it more than just an athletic challenge but also part of local life.