In 117 days · Sun, Feb 14, 2027
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Sunday, February 14th, 2027
6542 Fig Street, Arvada CO
Half · 5K
17–40°F · low rain risk
See last 10 years
On this date: rain 1 of the last 10 years
2026
30–56°F
dry
2025
22–45°F
rain
2024
14–41°F
dry
2023
23–43°F
dry
2022
16–48°F
dry
2021
-8–2°F
dry
2020
9–46°F
dry
2019
27–54°F
dry
2018
27–58°F
dry
2017
22–45°F
dry
Best months to race in Colorado →
Race-day forecast says layers
17°F at the start.
Gloves, ear warmers, throwaway layers, hand warmers — delivered before race day.
About this race
The Ralston Creek races feature a fun winter half-marathon and 5K run conveniently located on the west side of the Denver Metro Area in Arvada, Colorado. The courses cover a scenic mix of road and bike path over rolling terrain, and an optional early start time for half-marathon runners who expect to take more than 2 hours 45 minutes to complete the course!
Half-Marathon entry is limited to the first 650 registrations. 5K registration is limited to the first 350 entries. Once a distance has filled, we cannot accept any additional entries for that distance.
Your entry fee includes entry into the race, a finisher's medal (for half-marathon runners who complete the course), FREE race photo downloads, fun music, hot cocoa and tasty quesadillas fresh off the grill!!!
Long sleeve adult tech shirts will be included with all half marathon entries. 5k entries will come with a short sleeve t-shirt or an upgrade to a long sleeve tech shirt for $5.
This is also the final race in the Racing Underground Winter Running Series. The three-race series includes the Stocking Run 5K in December, the Yeti Chase 5K/10K in January, and the Ralston Creek Half-Marathon & 5K in February. Choose from the 5K-5K-5K series or the 5K-10K-Half Marathon Series.
WINTER RUNNING SERIES
Series Finisher Awards to all runners who finish all three series races, and Overall Awards to the top series finisher in each age category!
December 12, 2026: Superior Stocking Run 5K (Superior, Colorado)
January 24, 2027: Yeti Chase 5K/10K (Lakewood, Colorado)
February 14, 2027: Ralston Creek Half Marathon & 5K (Arvada, Colorado)
Course map
Train with a club
Run clubs near Arvada to train with before race day.
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