Monthly weather forecast and climate
Hercules, CA

Average sea temperature - Hercules, CA

The best month for swimming (with the highest average sea temperature) is September (57°F).
The coldest month (with the lowest average sea temperature) is April (52.6°F).

Average daylight - Hercules, CA

The month with the longest days is June (Average daylight: 14.8h).
The month with shortest days is December (Average daylight: 9.6h).