What race distances can I run in Castro Valley?
Castro Valley has 5K (3), Half Marathon (4). The 5K is usually the easiest entry point if you are new, and the links above jump straight to each distance.
California · Race calendar
Running Races in Castro Valley, California
Upcoming running races in and near Castro Valley, California - 5Ks, 10Ks, half marathons and more, with dates, pricing, finish-time stats, start-line maps, and local run clubs to train with.
4 upcoming races · 3 with finish-time stats
By the numbers
The Biggest and Longest-Running
The Castro Valley races that stand out on the numbers: the biggest field, and the longest unbroken run of editions.
How we calculate these stats: RunSesh calculates these figures from the most recent published results of past editions, sourced from RunSignup. We show aggregates only: field size, winning and median times, and the cutoff. We never publish individual finisher tables. Last updated Jul 27, 2026.
Common Questions About Racing in Castro Valley
When is race season in Castro Valley?
January is the busiest month for races in Castro Valley, with 2 of the 4. If you are flexible on the date, that is the quickest way to narrow things down.
How early should I register for a race in Castro Valley?
3 of the 4 races in Castro Valley already have a price increase scheduled, so entry gets more expensive the longer you leave it. Race pricing almost always steps up as the date approaches, and signing up early is usually the cheapest option.
Are Castro Valley races beginner-friendly?
Yes, for the most part. Across the 3 races in Castro Valley with published results, the typical median finish is around 2:37:28, which means half of every one of those fields came in slower than that. Recreational runners and walk-runners are the bulk of these fields, not the exception.
Where can I train for a race in Castro Valley?
Browse Castro Valley run clubs on RunSesh to find a training group at your pace.
Are there trail races near Castro Valley?
Yes, 2 races around Castro Valley get you off the pavement: 2 are trail races. Surfaces are not always published, so it is worth checking a specific race before you register.