Boulderthon: Downtown Boulder Marathon
Race Date
Sep 27, 2026
Location
Boulder, CO
Quick facts
- Date
- Sunday, September 27, 2026
- Location
- Boulder, Colorado
- Distance
- Half marathon (13.1 mi) + 26.2M, 10K, 5K run | kids run
- Course
- Loop Course
- Terrain
- Road
- USATF certified
- Yes
Course Info
USATF CertifiedCourse Type
Loop Course
Terrain
road
Difficulty
Rolling Hills
Net Drop/km
-0.24 m
Separation
1.3%
Also Offers
USATF Certified Course
CO25005DT · Boulderthon Half Marathon
Relatively flat with minimal net elevation change. Loop course — start and finish are close together.
Quality Score
first year
no finisher counts yet
small race — neutral
needs a few years of results
USATF certified · 3 timing sources
no finisher data yet
no winner time yet
typical high 77°F
Race Day Weather
5-year historical avgStart (Low)
48°
Afternoon (High)
77°
Warm — hydration strategy is key, start conservatively
0.0"
Precipitation
9 mph
Wind
47%
Humidity
Frequently asked
When is the Boulderthon: Downtown Boulder Marathon?
The Boulderthon: Downtown Boulder Marathon is held on Sunday, September 27, 2026.
Where does the Boulderthon: Downtown Boulder Marathon take place?
It takes place in Boulder, Colorado.
What distances does the Boulderthon: Downtown Boulder Marathon offer?
The half marathon (13.1 miles), plus 26.2M, 10K, 5K run | kids run.
Is the Boulderthon: Downtown Boulder Marathon course flat and good for a PR?
The Boulderthon: Downtown Boulder Marathon is a rolling hills, loop course course. The course is USATF-certified, so finish times can be used for qualifying.
HalfRuns editorial — independent, no paid placement.
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