Thumb Coast Marathon
Race Day Weather
Cold start — layer up
Runners will start in chilly 38°F conditions — dress in layers for the corral and plan to shed early. Temperatures rising to 47°F through the course will gradually increase perceived effort in the second half. Light winds shouldn't be a major factor for pacing. Moderate humidity at 69% is worth noting for effort level, especially in later miles.
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Race Info
The Thumb Coast Marathon is a point-to-point race along Lake Huron's Saginaw Bay shoreline in Michigan's Thumb region, starting in downtown Caseville and finishing on Main Street in Port Austin. The USATF-certified course is flat and fully paved, gaining about 265 feet over 26.2 miles and passing Point Crescent State Park near the finish. It is a Boston Qualifier: 8.9% of finishers in the 2025 inaugural race hit a BQ time, and the course carries a 99.45 course score, the second-fastest marathon course in Michigan. Race weekend also includes a half marathon starting at Sleeper State Park and a 5K in downtown Port Austin. Source
