Clo Cow Half Marathon, 10K & 5K

The Clo Cow Half Marathon, 10K & 5K returns to Petaluma, California on October 11, 2026. Participants will enjoy a scenic route through Historic Downtown and the surrounding farmland, where sheep and moo-cows add a unique charm along the course.
Race morning in Petaluma is known for its mild temperatures; expect averages around 17.9°C with minimums of 11.5°C and maximums reaching up to 24.3°C, making it comfortable yet slightly warm as you run through rolling hills and farmland. The air will feel just right, not too humid at 71%, but a gentle breeze with an average speed of 8.4 km/h can make the pace more challenging.
This event has been running for several years now and continues to grow in popularity; it is supported by local community efforts that benefit both runners and residents alike through scholarships and charity programs. With over one thousand participants each year, this race not only showcases Petaluma's natural beauty but also celebrates its vibrant spirit of giving back.
The 10K (10km), the Half Marathon (21km), and the 5K (5km) courses take you through varied terrain with firm yet slightly soft trail conditions. The course features notable route elements like climbs that offer sweeping views, making each step rewarding for both experienced runners and newcomers.
At the start line in Downtown Petaluma, expect a gradual elevation gain followed by some level stretches before reaching the finish at the same location. Along the way, several aid stations will provide water and snacks to keep you fueled throughout your run. The UV index of 4.0 (Moderate) indicates that sunscreen is recommended.

10K | 10km, Half Marathon | 21km, 5K | 5km
To register for the Clo Cow Half Marathon, 10K & 5K visit https://raceroster.com/events/2026/115095/clo-cow-half-marathon-10k-and-5k. Early bird registration closes on August 31, 2026; the regular fee is $78.45 for adults and $60.32 for kids.
Pick up your bib at Petaluma City Hall from September 1 to October 9, 2026 during business hours with a valid photo ID. First-timers should arrive early on race day fully prepared; bring water or sports drink, wear comfortable running gear, and ensure you have appropriate footwear for the firm yet slightly soft trail conditions.
The Clo Cow Half Marathon, 10K & 5K is worth attending because it not only offers a challenging course through picturesque Petaluma but also supports local community initiatives.