National Weather Service Forecast for: Fontana CA
Issued by: National Weather Service San Diego, CA
Updated: 12:04 pm PST Feb 1, 2026
 
Overnight

Overnight: Mostly clear, with a low around 55. Calm wind.
Mostly Clear
 Monday

Monday: Sunny, with a high near 78. Light and variable wind becoming west 5 to 10 mph in the afternoon.
Sunny
 Monday
Night
Monday Night: Mostly clear, with a low around 55. West wind around 5 mph becoming calm.
Mostly Clear
 Tuesday

Tuesday: Sunny, with a high near 82. North wind 5 to 15 mph, with gusts as high as 25 mph.
Sunny
 Tuesday
Night
Tuesday Night: Clear, with a low around 57. North wind around 15 mph, with gusts as high as 25 mph.
Clear
 Wednesday

Wednesday: Sunny, with a high near 84.
Sunny
 Wednesday
Night
Wednesday Night: Clear, with a low around 57.
Clear
 Thursday

Thursday: Sunny, with a high near 80.
Sunny
 Thursday
Night
Thursday Night: Partly cloudy, with a low around 57.
Partly Cloudy
Lo 55 °F Hi 78 °F Lo 55 °F Hi 82 °F Lo 57 °F Hi 84 °F Lo 57 °F Hi 80 °F Lo 57 °F

Air Quality Alert
 

Overnight
 
 Mostly clear, with a low around 55. Calm wind.
Monday
 
 Sunny, with a high near 78. Light and variable wind becoming west 5 to 10 mph in the afternoon.
Monday Night
 
 Mostly clear, with a low around 55. West wind around 5 mph becoming calm.
Tuesday
 
 Sunny, with a high near 82. North wind 5 to 15 mph, with gusts as high as 25 mph.
Tuesday Night
 
 Clear, with a low around 57. North wind around 15 mph, with gusts as high as 25 mph.
Wednesday
 
 Sunny, with a high near 84.
Wednesday Night
 
 Clear, with a low around 57.
Thursday
 
 Sunny, with a high near 80.
Thursday Night
 
 Partly cloudy, with a low around 57.
Friday
 
 Mostly sunny, with a high near 75.
Friday Night
 
 Patchy fog. Otherwise, partly cloudy, with a low around 54.
Saturday
 
 Patchy fog. Otherwise, mostly sunny, with a high near 76.
Saturday Night
 
 Mostly clear, with a low around 54.
Sunday
 
 Sunny, with a high near 79.

 

Forecast from NOAA-NWS for Fontana CA.