San Lorenzo River Trail Run
Race Day Weather
Comfortable temps
Starting at 60°F, heat will be a factor from the gun — go out conservative and stay on top of hydration. Temperatures rising to 69°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 74% is worth noting for effort level, especially in later miles.
Get forecast alerts for San Lorenzo River Trail Run
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 San Lorenzo River Trail Run is an annual trail race in Santa Cruz, California, organized by Coastal Trail Runs. Held each July, it starts and finishes at Harvey West Park and offers 10K, Half Marathon, 30K, Marathon, and 50K distances, with the marathon run as two half-marathon loops. The course crosses the San Lorenzo River multiple times and passes through coastal redwood forest, stream canyons, and chaparral ridges toward Henry Cowell Redwoods State Park.