Colfax Half Marathon
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May 16, 2027
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The Colfax Half Marathon is the half marathon of the Denver Colfax Marathon weekend, held on a Sunday in May in Denver, Colorado. The weekend, first run in 2006, also includes the Colfax Marathon, an Urban 10 Miler, a marathon relay and a 5K. The half marathon starts at 6:30 a.m. on the east side of Ferril Lake in City Park and finishes in City Park. It passes the Denver Museum of Nature and Science and runs along Montview Boulevard before spending a mile inside Denver Zoo. It then follows Colfax Avenue past the Cathedral Basilica, the Capitol and Civic Center Park. The route goes through Denver Fire Station No. 1, where firefighters give high-fives, and passes the Convention Center and the 16th Street Mall. The homestretch runs along 17th Avenue into City Park. The time limit is 3 hours 25 minutes. The event record for men is 1:03:05, set by Emad Bashir-Mohammed in 2025.
Typical climate for the race month — an estimate, not a forecast or a race-day record
Mid-May in Denver averages a daily high of about 22°C and a low of about 6°C, with some precipitation on around ten days of the month, so the 6:30 a.m. start is cool.
The Race
Denver
The Colfax Marathon was first held in 2006, with about 4,000 people taking part in the inaugural race. The initial course followed Colfax Avenue for almost the entire race, from the Aurora Sports Park west through Denver to a finish near Colorado Mills in west Lakewood. The organisers describe it as the largest marathon weekend in the Rocky Mountain region.
In 2015 Hais Welday of Eritrea won the half marathon in 1:06:44, beating the record that Patrick Rizzo set in 2012. In 2024 Emad Bashir-Mohammed of Aurora set a new record of 1:06:13, and in 2025 he lowered it to 1:03:05 in the new Colorado Half Marathon Showdown for local elite runners.
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01:03:05
Emad Bashir-Mohammed (2025)
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