Champlain Islands Marathon
Race Day Weather
Cool start — fast day potential, warming through the race
A cool 42°F at the start line is ideal for fast times — expect to warm up quickly once you're moving. Temperatures rising to 55°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 70% is worth noting for effort level, especially in later miles.
Pace Calculator
Get forecast alerts for Champlain Islands Marathon
We'll text or email you when the forecast shifts — so you can adjust gear, pacing, and strategy. Max one per day.
Get your personalized Champlain Islands Marathon race plan
Weather-adjusted pacing, per-mile terrain splits, fueling timeline with aid stations, packing checklist, carb tracker, spectator guide — all personalized to your goal and race-day conditions.
Race Info
The USATF-certified (VT24002JK) marathon and half marathon begin and end at Folsom Elementary School in South Hero, VT, near the former home of Clarence H. DeMar, seven-time Boston Marathon winner. The half marathon course is out and back along the west shore of South Hero and Grand Isle, through farms, apple orchards, and summer cottages, with flat to rolling, entirely paved terrain. The marathon is two laps of the half marathon course. Start/finish elevation is about 190 feet, with a high point of 210 feet (miles 1 and 25) and a low point of 100 feet. The marathon cutoff is 6 hours; the half marathon cutoff is 4 hours. The course qualifies for Boston Marathon entry. The race was formerly named the Green Mountain Marathon; its current certification (VT24002JK) supersedes the earlier certification issued under that name.