In 129 days · Thu, Dec 31, 2026
Don't let race day sneak up
One email during race week. That's it.
When
Thursday, December 31st, 2026
Where
17930 Lake Chabot Rd, Castro Valley CA
Distances
Half · 5K · 10K
Typical weather
43–56°F · some rain risk
See last 10 years
On this date: rain 2 of the last 10 years
2025
43–51°F
rain
2024
38–55°F
dry
2023
46–56°F
dry
2022
50–56°F
rain
2021
37–51°F
dry
2020
44–56°F
dry
2019
40–59°F
dry
2018
41–53°F
dry
2017
42–56°F
dry
2016
39–51°F
dry
Best months to race in California →
About this race
Race Overview
- Date: New Year's Eve, Thursday, 12/31/2026
- Location: 17930 Lake Chabot Rd, Castro Valley, CA
- Events: 5K, 10K, and half marathon
- Registration: Join us at this link
Event Highlights
- Trail Opportunities: Whether you're looking to squeeze in your first trail run or you're looking to log that 1,000th mile before the clock strikes midnight, this is your chance.
- Double Event: Make it a double and join us on both New Year's Eve and New Year's Day to earn the Brazen New Year Mega-Medal!
- Separate Registration Required: Each race is a unique event on its own and requires separate registration.
- Back-to-Back Events: This year we will have back-to-back events at Lake Chabot, Castro Valley.
Course map
Train with a club
Run clubs near Castro Valley to train with before race day.
See all run clubs near Castro Valley →
Suggested Races
Organize this race?
Claim it free to manage your listing — and get it featured for free, while spots last.