National Weather Service Forecast for: Grass Valley CA
Issued by: National Weather Service Sacramento, CA
Updated: 1:21 am PST Dec 17, 2025
 
Overnight

Overnight: Showers and possibly a thunderstorm. Patchy fog. Low around 45. South wind around 7 mph. Chance of precipitation is 100%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Showers and
Patchy Fog
 Wednesday

Wednesday: Showers likely and possibly a thunderstorm before 1pm, then a slight chance of showers between 1pm and 2pm. Areas of fog before 5pm. Otherwise, cloudy, then gradually becoming mostly sunny, with a high near 55. South wind 5 to 9 mph becoming light in the afternoon. Chance of precipitation is 60%. New precipitation amounts between a quarter and half of an inch possible.
Showers
Likely and
Areas Fog
 Wednesday
Night
Wednesday Night: A 30 percent chance of showers, mainly before midnight. Areas of fog after 9pm. Otherwise, partly cloudy, with a low around 40. Calm wind.
Chance
Showers and
Areas Fog
 Thursday

Thursday: A 20 percent chance of showers after 10am. Partly sunny, with a high near 58. Light and variable wind.
Slight Chance
Showers
 Thursday
Night
Thursday Night: Showers likely, mainly after 4am. Mostly cloudy, with a low around 45. Calm wind. Chance of precipitation is 60%.
Showers
Likely
 Friday

Friday: Showers, with thunderstorms also possible after 4pm. High near 52. Chance of precipitation is 90%.
Showers

 Friday
Night
Friday Night: Showers and possibly a thunderstorm. Low around 47. Chance of precipitation is 100%.
Showers

 Saturday

Saturday: Showers. Cloudy, with a high near 55.
Showers

 Saturday
Night
Saturday Night: Showers. Cloudy, with a low around 48.
Showers
Lo 45 °F Hi 55 °F Lo 40 °F Hi 58 °F Lo 45 °F Hi 52 °F Lo 47 °F Hi 55 °F Lo 48 °F

 

Overnight
 
 Showers and possibly a thunderstorm. Patchy fog. Low around 45. South wind around 7 mph. Chance of precipitation is 100%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Wednesday
 
 Showers likely and possibly a thunderstorm before 1pm, then a slight chance of showers between 1pm and 2pm. Areas of fog before 5pm. Otherwise, cloudy, then gradually becoming mostly sunny, with a high near 55. South wind 5 to 9 mph becoming light in the afternoon. Chance of precipitation is 60%. New precipitation amounts between a quarter and half of an inch possible.
Wednesday Night
 
 A 30 percent chance of showers, mainly before midnight. Areas of fog after 9pm. Otherwise, partly cloudy, with a low around 40. Calm wind.
Thursday
 
 A 20 percent chance of showers after 10am. Partly sunny, with a high near 58. Light and variable wind.
Thursday Night
 
 Showers likely, mainly after 4am. Mostly cloudy, with a low around 45. Calm wind. Chance of precipitation is 60%.
Friday
 
 Showers, with thunderstorms also possible after 4pm. High near 52. Chance of precipitation is 90%.
Friday Night
 
 Showers and possibly a thunderstorm. Low around 47. Chance of precipitation is 100%.
Saturday
 
 Showers. Cloudy, with a high near 55.
Saturday Night
 
 Showers. Cloudy, with a low around 48.
Sunday
 
 Showers, with thunderstorms also possible after 10am. Some of the storms could produce heavy rainfall. Cloudy, with a high near 54.
Sunday Night
 
 Showers and possibly a thunderstorm. Some of the storms could produce heavy rainfall. Cloudy, with a low around 48.
Monday
 
 Showers. The rain could be heavy at times. Mostly cloudy, with a high near 53.
Monday Night
 
 Showers likely. Mostly cloudy, with a low around 45.
Tuesday
 
 Showers likely. Mostly cloudy, with a high near 53.

 

Forecast from NOAA-NWS for Grass Valley CA.