Boulderthon Marathon
Race Day Weather
Cool start, warming significantly
Runners will face a temperature rise from 50°F at the start to 80°F by the finish. With light winds at 6 mph and low humidity at 38%, conditions will be manageable early but require caution as temperatures climb. Adjust pacing to start conservatively, especially around the notable descent from mile 11 to 12, where the tailwind may offer a brief advantage.
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Race Info
Named among the Best Fall Marathons by Runner's World, #5 Best Half Marathon in the US by Active, as well as #1 Best in Colorado and one of the "Most Beautiful Marathons in the World" by HalfMarathons.Net, Boulderthon drew over 6,000 runners from all 50 states and 18 countries in 2023, and has doubled in size every year since its inception. Source
