National Weather Service Forecast for: Ontario International Arpt CA
Issued by: National Weather Service San Diego, CA
Updated: 2:58 am PST Dec 22, 2025
 
Today

Today: Partly sunny, with a high near 74. Calm wind becoming west around 5 mph in the afternoon.
Partly Sunny

 Tonight

Tonight: Mostly cloudy, with a low around 52. West wind around 5 mph becoming calm.
Mostly Cloudy

 Tuesday

Tuesday: Rain likely, mainly after 4pm. Mostly cloudy, with a high near 67. Calm wind becoming southeast around 5 mph in the afternoon. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.
Slight Chance
Rain then
Rain Likely
 Tuesday
Night
Tuesday Night: Rain. The rain could be heavy at times. Low around 57. East wind around 10 mph. Chance of precipitation is 90%. New precipitation amounts between 1 and 2 inches possible.
Heavy Rain

 Wednesday

Wednesday: Rain, with thunderstorms also possible after 10am. Some of the storms could produce heavy rainfall. High near 63. South wind 10 to 15 mph, with gusts as high as 20 mph. Chance of precipitation is 100%. New rainfall amounts between 2 and 3 inches possible.
Heavy Rain

 Wednesday
Night
Wednesday Night: Rain and possibly a thunderstorm. Some of the storms could produce heavy rainfall. Low around 53. Chance of precipitation is 100%.
Heavy Rain

 Christmas
Day
Christmas Day: Rain. High near 62. Chance of precipitation is 90%.
Rain

 Thursday
Night
Thursday Night: Showers. Cloudy, with a low around 51.
Showers

 Friday

Friday: Showers. Cloudy, with a high near 60.
Showers
Hi 74 °F Lo 52 °F Hi 67 °F Lo 57 °F Hi 63 °F Lo 53 °F Hi 62 °F Lo 51 °F Hi 60 °F

Air Quality Alert
Flood Watch
Dense Fog Advisory
 

Today
 
 Partly sunny, with a high near 74. Calm wind becoming west around 5 mph in the afternoon.
Tonight
 
 Mostly cloudy, with a low around 52. West wind around 5 mph becoming calm.
Tuesday
 
 Rain likely, mainly after 4pm. Mostly cloudy, with a high near 67. Calm wind becoming southeast around 5 mph in the afternoon. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.
Tuesday Night
 
 Rain. The rain could be heavy at times. Low around 57. East wind around 10 mph. Chance of precipitation is 90%. New precipitation amounts between 1 and 2 inches possible.
Wednesday
 
 Rain, with thunderstorms also possible after 10am. Some of the storms could produce heavy rainfall. High near 63. South wind 10 to 15 mph, with gusts as high as 20 mph. Chance of precipitation is 100%. New rainfall amounts between 2 and 3 inches possible.
Wednesday Night
 
 Rain and possibly a thunderstorm. Some of the storms could produce heavy rainfall. Low around 53. Chance of precipitation is 100%.
Christmas Day
 
 Rain. High near 62. Chance of precipitation is 90%.
Thursday Night
 
 Showers. Cloudy, with a low around 51.
Friday
 
 Showers. Cloudy, with a high near 60.
Friday Night
 
 A chance of showers. Mostly cloudy, with a low around 45.
Saturday
 
 A chance of showers. Mostly sunny, with a high near 63.
Saturday Night
 
 A slight chance of showers. Partly cloudy, with a low around 42.
Sunday
 
 Mostly sunny, with a high near 66.

 

Forecast from NOAA-NWS for Ontario International Arpt CA.