National Weather Service Forecast for: Fontana CA
Issued by: National Weather Service San Diego, CA
Updated: 12:35 pm PST Dec 22, 2025
 
Tonight

Tonight: Patchy fog after 4am. Otherwise, mostly cloudy, with a low around 52. Southwest wind around 5 mph becoming calm.
Mostly Cloudy
then Patchy
Fog
 Tuesday

Tuesday: A chance of showers, mainly after 4pm. Patchy fog before 10am. Otherwise, mostly cloudy, with a high near 66. Southeast wind around 5 mph. Chance of precipitation is 30%.
Chance
Showers and
Patchy Fog
 Tuesday
Night
Tuesday Night: Showers, mainly after 10pm. The rain could be heavy at times. Low around 55. Light southeast wind increasing to 10 to 15 mph after midnight. Winds could gust as high as 25 mph. Chance of precipitation is 90%. New precipitation amounts between 1 and 2 inches possible.
Heavy Rain

 Wednesday

Wednesday: Showers, with thunderstorms also possible after 10am. Some of the storms could produce heavy rainfall. High near 62. South wind 5 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 100%. New rainfall amounts between 2 and 3 inches possible.
Heavy Rain

 Wednesday
Night
Wednesday Night: Showers and possibly a thunderstorm. Some of the storms could produce heavy rainfall. Low around 53. Southwest wind 5 to 10 mph becoming light and variable. Winds could gust as high as 20 mph. Chance of precipitation is 100%. New rainfall amounts between a quarter and half of an inch possible.
Heavy Rain

 Christmas
Day
Christmas Day: Showers. High near 62. Chance of precipitation is 80%.
Showers

 Thursday
Night
Thursday Night: Showers. Low around 51. Chance of precipitation is 90%.
Showers

 Friday

Friday: Showers. Mostly cloudy, with a high near 60.
Showers

 Friday
Night
Friday Night: Showers likely, mainly before 10pm. Mostly cloudy, with a low around 45.
Showers
Likely
Lo 52 °F Hi 66 °F Lo 55 °F Hi 62 °F Lo 53 °F Hi 62 °F Lo 51 °F Hi 60 °F Lo 45 °F

Flood Watch
Wind Advisory
 

Tonight
 
 Patchy fog after 4am. Otherwise, mostly cloudy, with a low around 52. Southwest wind around 5 mph becoming calm.
Tuesday
 
 A chance of showers, mainly after 4pm. Patchy fog before 10am. Otherwise, mostly cloudy, with a high near 66. Southeast wind around 5 mph. Chance of precipitation is 30%.
Tuesday Night
 
 Showers, mainly after 10pm. The rain could be heavy at times. Low around 55. Light southeast wind increasing to 10 to 15 mph after midnight. Winds could gust as high as 25 mph. Chance of precipitation is 90%. New precipitation amounts between 1 and 2 inches possible.
Wednesday
 
 Showers, with thunderstorms also possible after 10am. Some of the storms could produce heavy rainfall. High near 62. South wind 5 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 100%. New rainfall amounts between 2 and 3 inches possible.
Wednesday Night
 
 Showers and possibly a thunderstorm. Some of the storms could produce heavy rainfall. Low around 53. Southwest wind 5 to 10 mph becoming light and variable. Winds could gust as high as 20 mph. Chance of precipitation is 100%. New rainfall amounts between a quarter and half of an inch possible.
Christmas Day
 
 Showers. High near 62. Chance of precipitation is 80%.
Thursday Night
 
 Showers. Low around 51. Chance of precipitation is 90%.
Friday
 
 Showers. Mostly cloudy, with a high near 60.
Friday Night
 
 Showers likely, mainly before 10pm. Mostly cloudy, with a low around 45.
Saturday
 
 A slight chance of showers. Partly sunny, with a high near 60.
Saturday Night
 
 A slight chance of showers. Partly cloudy, with a low around 44.
Sunday
 
 Sunny, with a high near 62.
Sunday Night
 
 Partly cloudy, with a low around 45.
Monday
 
 A slight chance of showers. Mostly sunny, with a high near 65.

 

Forecast from NOAA-NWS for Fontana CA.