Founders Half Marathon
Race Day Weather
Cool start, gradual warm-up
Runners will face a cool start at 38°F, gradually warming to 47°F. Light winds from the W will be a non-factor with max speeds under 8 mph. With average humidity at 57%, hydration should be prioritized, but runners can maintain a steady pace without significant adjustments. A throwaway layer may be useful during pre-race warm-ups.
Pace Calculator
Get forecast alerts for Founders Half Marathon
We'll text or email you when the forecast shifts — so you can adjust gear, pacing, and strategy. Max one per day.
Race Info
The Founders Half Marathon is a 13.1-mile out-and-back race in Potomac, Maryland, organized by the DC Road Runners Club. The course runs along the C&O Canal Towpath from the Carderock Recreation Area, with two water stops at Lock 10 and Lock 6 passed twice each. It is race #2 of DCRRC's winter Snowball Series and was known as the Gar Williams Half Marathon before 2025, named for a past president of the club and of the Road Runners Club of America.
