Walnut Creek Half Marathon, Relay, 10K & 5K

Saturday, December 14, 2019 • Walnut Creek, CA • Course Map

Note: The half marathon distance has been replaced with a 10-mile distance in 2020. The description below reflects the 2019 race.

Known for its wealth of parks and open green space, this East Bay city located just across the bay from San Francisco and within a short drive of nearby Oakland plays host to the 9th annual running of the Walnut Creek Half Marathon, Relay, 10K & 5K, which will also mark the final race in a series of half marathons that take place across the state throughout the year, named the California Half Marathon Series.

Lying in the shadow of nearby Mount Diablo State Park, the 20,000-acre park whose double pyramid mountains are a familiar sight to locals and residents from around Northern California, Walnut Creek is home to a number of parks large and small, from the Walnut Creek Open Space near the race starting line to the city’s Civic Park (where the race finish line lies).

The race also takes runners through portions of the Lime Ridge Regional Open Space, whose more than 1,200 acres are home to 25 miles of trails through its abundant oak woodlands and grasslands, and lies near the turnaround point for the race.

Runners start the half marathon with the 5K at Walnut Creek’s Civic Park. From there, they follow a clockwise loop route along Oak Road, Treat Boulevard and Cowell Road to the the northern end of the Lime Ridge Open Space before turning right onto Ygnacio Valley Road, which they’ll follow as it heads southwest all the way into Heather Farm Park.

The half marathon’s most challenging stretch lies in the middle miles of the race, as runners are making their way northeast along Cowell Road up into the Lime Ridge Regional Open Space area.

The course rises more than 350 feet in elevation between the 4th and 7th mile markers, at the area known as Ygnacio Hill, and runners will climb this hill for roughly the next mile and a half until they reach the crest and start heading downhill through Diablo Shadows and Ygnacio Valley.

Race Weather & Climate

Nestled among the hills of California’s East Bay, roughly 25 miles east of San Francisco, Walnut Creek typically sees quite cool and occasionally cold weather in the late fall and early winter season.

In December, temperatures range between 39°F and 55°F — on the day of the race (Dec. 14), the average low is 39°F and the average high is 55°F — while rainfall totals average just under 2.8 inches for the month.

Past Results

Course Map

See the race route map for the Walnut Creek Half Marathon here.

Starting Time

7:00 AM


  • $60 – $102 for the half marathon
  • $102 – $157 for the relay
  • $55 – $87 for the 10K
  • $40 – $68 for the 5K


To reserve your spot in the 2019 running of the Walnut Creek Half Marathon or 5K race, register online at ChronoTrack here.

Official Race Website



Ever run in the Walnut Creek Half Marathon? Share your impressions here, or post your review in the Comments below.

See more races in: December, California

5 comments… add one
  • Pam Smith October 18, 2017, 8:56 pm

    What is the time limit to complete the half marathon.

  • John November 27, 2015, 12:19 pm

    I volunteer to help but I haven’t heard back. I need A number that I can call or email address so I can contact someone about this information.

  • Marshall Cosby December 13, 2014, 2:49 pm

    My husband ran the Walnut Creek Half M this morning and realize that he is missing his cell phone. We believe he lost it at the drop bag site. Can you please provide me with the lost and found representative ?

    Thank you,
    Tonya Cosby

  • Jesse Montellano December 13, 2014, 12:30 am

    Can I register for the half the day of the race?


  • Patricia Di Fede December 12, 2014, 11:53 am

    question I want to sign up to for the 5k can I sign up race day?


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