When in September are most 5K races held?
The busiest weekend in Colorado is September 11 and September 12, with 4 of them, 3 of those on Saturday, September 11. Another 4 fall on a weekday, which is worth knowing if you are traveling for one.
Race calendar · September 2027 · Colorado
5K Races in Colorado in September 2027
Every 5K in Colorado in September 2027, all 11 of them, sorted by date. Dates, entry fees, finish-time stats from past results, and start-line maps.
What the field actually runs
September 5K Races, By the Numbers
38:12Median finish time
19:06Median winning time
208Median field size
8September 5K races with published results
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 Nov 12, 2026.
When in September
The September Race Weekends
5K races are not spread evenly across September. Here is how the calendar actually falls, weekend by weekend, which is the part worth knowing before you book a trip or plan a taper around one.
By the numbers
The Biggest Field
The largest field of any September 5K in Colorado, from the most recent published results.
Colorado 5K Races by City in September
All 5K Runs in Colorado in September
11 total Wed, Sep 1, 20272027 Suicide Prevention Color Walk/Run Center, COFrom $25Details Mon, Sep 6, 2027Labor Day Half Marathon Parker, COFrom $30Details Tue, Sep 7, 2027Spirit of the Valley 5k Grand Junction, COFrom $25Details Sat, Sep 11, 2027The Denver 5k Denver, COFrom $44Details Sat, Sep 11, 2027Break Your Neck: Walk, Run, or Roll Pueblo, CORegistration opens Dec 7FreeDetails Sat, Sep 11, 2027Golden Harvest Half Marathon & 5K/10K - Denver Denver, COFrom $32Details Sun, Sep 12, 2027Golden Harvest Half Marathon & 5K/10K Colorado Springs, COFrom $30Details Fri, Sep 17, 2027Severance Glow 5K Run or Walk Severance, CORegistration opens Dec 1From $32Details Sat, Sep 18, 2027Autumn Run Buena Vista, CORegistration opens Mar 1, 2027From $30Details Sat, Sep 18, 2027All-Out Fall Fest Westminster, COFrom $35Details Sat, Sep 18, 2027Front Range Pursuit 5k Run/Walk Denver, CORegistration opens Dec 1From $39Details
Common Questions About Running a September 5K in Colorado
What is a good 5K time?
Across the 8 of these September 5K races with published results from past editions, the median finisher ran 38:12, and the median winning time was 19:06. So anything under 38:12 puts you in the faster half of a typical field. That is the middle of these RunSignup fields, walkers and charity entrants included, not a national average.
How big is a typical September 5K field?
The median one finished 208 runners, across the 8 of these September 5K races with published results from past editions. Most are far smaller than the big-city events people picture, which means less crowding at the start and a friendlier field, with a last recorded finisher at 1:09:03.
Are there trail 5K races in Colorado in September?
Yes, one race around Colorado gets you off the pavement: 1 is a trail race.