National Weather Service Forecast for: Hercules CA
Issued by: National Weather Service San Francisco Bay Area/Monterey, CA
Updated: 1:24 pm PST Dec 17, 2025
 
Tonight

Tonight: Patchy dense fog after 2am. Otherwise, increasing clouds, with a low around 46. Southwest wind around 6 mph becoming calm in the evening.
Mostly Cloudy
then Patchy
Dense Fog
 Thursday

Thursday: Patchy dense fog before 10am. Otherwise, cloudy, then gradually becoming mostly sunny, with a high near 56. Calm wind becoming west northwest around 5 mph in the afternoon.
Patchy Dense
Fog then
Partly Sunny
 Thursday
Night
Thursday Night: A 40 percent chance of rain. Cloudy, with a low around 50. South southwest wind around 6 mph.
Chance Rain

 Friday

Friday: Rain, mainly after 10am. High near 56. South wind 8 to 13 mph, with gusts as high as 21 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.
Rain

 Friday
Night
Friday Night: Rain, mainly before 4am. Low around 52. South southwest wind 8 to 10 mph. Chance of precipitation is 90%. New precipitation amounts between a tenth and quarter of an inch possible.
Rain then
Rain Likely
 Saturday

Saturday: Rain, mainly after 10am. High near 54. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.
Rain

 Saturday
Night
Saturday Night: Rain before 10pm, then showers and possibly a thunderstorm after 10pm. Low around 53. Chance of precipitation is 90%.
Showers

 Sunday

Sunday: Showers and possibly a thunderstorm. Cloudy, with a high near 57.
Showers

 Sunday
Night
Sunday Night: Rain. Cloudy, with a low around 52.
Rain
Lo 46 °F Hi 56 °F Lo 50 °F Hi 56 °F Lo 52 °F Hi 54 °F Lo 53 °F Hi 57 °F Lo 52 °F

 

Tonight
 
 Patchy dense fog after 2am. Otherwise, increasing clouds, with a low around 46. Southwest wind around 6 mph becoming calm in the evening.
Thursday
 
 Patchy dense fog before 10am. Otherwise, cloudy, then gradually becoming mostly sunny, with a high near 56. Calm wind becoming west northwest around 5 mph in the afternoon.
Thursday Night
 
 A 40 percent chance of rain. Cloudy, with a low around 50. South southwest wind around 6 mph.
Friday
 
 Rain, mainly after 10am. High near 56. South wind 8 to 13 mph, with gusts as high as 21 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.
Friday Night
 
 Rain, mainly before 4am. Low around 52. South southwest wind 8 to 10 mph. Chance of precipitation is 90%. New precipitation amounts between a tenth and quarter of an inch possible.
Saturday
 
 Rain, mainly after 10am. High near 54. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.
Saturday Night
 
 Rain before 10pm, then showers and possibly a thunderstorm after 10pm. Low around 53. Chance of precipitation is 90%.
Sunday
 
 Showers and possibly a thunderstorm. Cloudy, with a high near 57.
Sunday Night
 
 Rain. Cloudy, with a low around 52.
Monday
 
 Rain likely. Cloudy, with a high near 54.
Monday Night
 
 Rain likely. Cloudy, with a low around 48.
Tuesday
 
 Rain. Mostly cloudy, with a high near 51.
Tuesday Night
 
 Rain. Cloudy, with a low around 49.
Wednesday
 
 Rain likely. Mostly cloudy, with a high near 53.

 

Forecast from NOAA-NWS for Hercules CA.