National Weather Service Forecast for: Ontario International Arpt CA
Issued by: National Weather Service San Diego, CA
Updated: 1:40 am PST Dec 5, 2025
 
Overnight

Overnight: Clear, with a low around 44. North wind around 5 mph.
Clear
 Friday

Friday: Sunny, with a high near 70. Calm wind becoming west around 5 mph in the afternoon.
Sunny
 Friday
Night
Friday Night: Clear, with a low around 47. West wind around 5 mph becoming calm in the evening.
Clear
 Saturday

Saturday: Sunny, with a high near 72. Calm wind becoming west around 5 mph in the afternoon.
Sunny
 Saturday
Night
Saturday Night: Clear, with a low around 48. Northwest wind around 5 mph becoming calm.
Clear
 Sunday

Sunday: Sunny, with a high near 75.
Sunny
 Sunday
Night
Sunday Night: Mostly clear, with a low around 50.
Mostly Clear
 Monday

Monday: Sunny, with a high near 79.
Sunny
 Monday
Night
Monday Night: Clear, with a low around 52.
Clear
Lo 44 °F Hi 70 °F Lo 47 °F Hi 72 °F Lo 48 °F Hi 75 °F Lo 50 °F Hi 79 °F Lo 52 °F

 

Overnight
 
 Clear, with a low around 44. North wind around 5 mph.
Friday
 
 Sunny, with a high near 70. Calm wind becoming west around 5 mph in the afternoon.
Friday Night
 
 Clear, with a low around 47. West wind around 5 mph becoming calm in the evening.
Saturday
 
 Sunny, with a high near 72. Calm wind becoming west around 5 mph in the afternoon.
Saturday Night
 
 Clear, with a low around 48. Northwest wind around 5 mph becoming calm.
Sunday
 
 Sunny, with a high near 75.
Sunday Night
 
 Mostly clear, with a low around 50.
Monday
 
 Sunny, with a high near 79.
Monday Night
 
 Clear, with a low around 52.
Tuesday
 
 Sunny, with a high near 81.
Tuesday Night
 
 Mostly clear, with a low around 52.
Wednesday
 
 Sunny, with a high near 81.
Wednesday Night
 
 Clear, with a low around 53.
Thursday
 
 Sunny, with a high near 80.

 

Forecast from NOAA-NWS for Ontario International Arpt CA.