Prepare for a true test of grit and determination at the Fog City Run, a challenging 5K that carves a "hilly" course through the vibrant Marina and Presidio neighborhoods of San Francisco, CA. Often hailed as the "Hardest 5k in San Francisco," this weekly race, including the upcoming event on January 21, 2026, promises an unforgettable experience for runners seeking to push their limits. Starting from The Blue Light at 1979 Union Street, the route plunges you into a dynamic urban and natural landscape, featuring demanding ascents like the Lyon Street Stairs and scenic stretches through Lover's Lane, culminating back on Union Street.

This unique 5K is more than just a race; it's a competitive community fixture that embraces San Francisco's famed topography. Runners can expect typical race day conditions around this time of year to include highs of 59°F and lows of 47°F, with a slight 14% chance of precipitation, making for invigorating running weather. Though informal, a locked closet is available for belongings at the start. The Fog City Run offers a compelling opportunity for those who thrive on competitive racing and wish to conquer a truly formidable 5K amidst the iconic beauty of the Bay Area.