San Francisco, California
Alcatraz is a cold-water, current-sensitive race where local marine guidance matters more than generic weather.
Typical race window
Monthly climate normal from 2016-2025 archive data.
13°C-19°C
30 km/h
52 km/h
1%
A typical day in June averages 0 mm of precipitation, with average gusts around 53 km/h. Treat this as planning context, not a live forecast.
Jan
14°C
Feb
15°C
Mar
15°C
Apr
16°C
May
17°C
Jun
19°C
Jul
19°C
Aug
20°C
Sep
21°C
Oct
20°C
Nov
17°C
Dec
14°C
Cold water, current, wind and visibility are the central swim variables.
Wind, fog and cool air can affect handling and clothing decisions.
The run is usually cooler than many races, but wind and fog can affect comfort.
Live race-day forecast
This race page stays evergreen. For date, start time and expected segment durations, open the race-day planner with San Francisco, California prefilled.