Race calendar · September 2026 · Colorado
Every 10K in Colorado in September 2026, all 5 of them, sorted by date. Dates, entry fees, finish-time stats from past results, and start-line maps.
5 10K races in September 2026
By the numbers
The September 10K races that stand out on the numbers: the biggest field, and the longest unbroken run of editions.
The busiest weekend in Colorado is September 26 and September 27, with 5 10K races on those two days, and the single busiest day is Saturday, September 26 with 3. Every one of them is on a Saturday or a Sunday.
As early as you can. 1 of these September 10K races already have a price increase on the calendar, and 5 are open for entry right now.
The typical entry is $30, with paid entries running from $25 up to $500. Entry fees climb as race day gets closer, so the same race is usually cheapest the week it opens.
August and October sit either side of September, which is where most people look next when a date does not fit.
