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.
Sep 4 - Sep 51
Sep 11 - Sep 122
Sep 18 - Sep 192
Sep 25 - Sep 261
By the numbers
The Biggest Field
The largest field of any September 5K in Missouri, from the most recent published results.
Common Questions About Running a September 5K in Missouri
What is a good 5K time?
Across the 4 of these September 5K races with published results from past editions, the median finisher ran 41:29, and the median winning time was 22:40. So anything under 41:29 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 80 runners, across the 4 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 1:26:46.
Are there trail 5K races in Missouri in September?
Yes, one race around Missouri gets you off the pavement: 1 is a trail race.