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Colorado Half Marathons in January

This is the calendar of all the Colorado half marathons in January. On these race calendars, not only will you be able to search the basics of cities and dates, but you’ll also be able to find January Colorado half marathons by difficulty, scenery, race size, and attributes like whether it’s pet-friendly, stroller-friendly, or has a great finisher party.

If you can’t find the half marathon you’re looking for in Colorado in January, it’s possible the race has not updated their date to the current year or has switched months. If you know a race belongs on this calendar or have any edits you’d like to suggest for an existing race in Colorado in January, you can email us [email protected].

Valkyrie Trail Race Half Marathon course in Colorado Springs, CO

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All-Out Polar Prowl logo
January 10, 2026
100-500 runners
Arvada, Colorado
January 18, 2026
100-500 runners
Westminster, Colorado

Running in Colorado

FAQ

What are the most popular Colorado half marathons?

The four most popular Colorado half marathons are the Denver Colfax Half Marathon, the REVEL Rockies Half Marathon, the Horsetooth Half Marathon, and Boulderthon.

What’s the best half marathons in Colorado for beginners in 2025?

We have three picks for the best beginner Colorado half marathons. The first is the Slacker Half Marathon for it’s fun fast downhill course. Secondly, Boulderthon, for it’s scenic course, huge crowds, and amazing production quality. And finally, the Denver Colfax Half Marathon for it’s notable and exciting course and race experience.

Which months can I run a half marathon in Colorado?

You can run a half marathon in Colorado in January, February, April, May, June, July, August, September, October, November, and December.

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