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 Sep 22, 2026.
When in October
The October Race Weekends
5K races do not spread evenly across October. The busiest weekend is October 17 and October 18, with 4 of them. Another 2 fall on a weekday.
Oct 3 – Oct 42
Oct 10 – Oct 113
Oct 17 – Oct 184
Oct 24 – Oct 251
Oct 31 – Nov 13
By the numbers
The Biggest and Longest-Running
The October 5K races that stand out on the numbers: the biggest field, and the longest unbroken run of editions.
Common Questions About Running an October 5K in Montana
When in October are most 5K races held?
The busiest weekend in Montana is October 17 and October 18, with 4 5K races on those two days, and the single busiest day is Saturday, October 17 with 3. Another 2 fall on a weekday, which is worth knowing if you are traveling for one.
When should I sign up for an October 5K?
As early as you can. 4 of these October 5K races already have a price increase on the calendar, and 14 are open for entry right now. Another 1 have published an opening date and have not opened yet.
How much does an October 5K cost to enter?
The typical entry is $30, with paid entries running from $10 up to $40, and 1 that are free to enter. Entry fees climb as race day gets closer, so the same race is usually cheapest the week it opens.
What is a good 5K time?
Across the 10 of these October 5K races with published results from past editions, the median finisher ran 33:39, and the median winning time was 19:04. So anything under 33:39 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 October 5K field?
The median one finished 106 runners, across the 10 of these October 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 1:06:44.
Are there trail 5K races in Montana in October?
Yes, 5 races around Montana get you off the pavement: 4 are trail races, and 1 mixes road and trail. Surfaces are not always published, so it is worth checking a specific race before you register.
5K Races in Other Months
September and November sit either side of October, which is where most people look next when a date does not fit.