National Weather Service Forecast for: Ontario International Arpt CA
Issued by: National Weather Service San Diego, CA
Updated: 10:18 am PDT May 26, 2026
 
This
Afternoon
This Afternoon: Mostly sunny, with a high near 69. Southwest wind around 15 mph, with gusts as high as 25 mph.
Mostly Sunny

 Tonight

Tonight: Patchy drizzle after 2am. Increasing clouds, with a low around 53. Southwest wind 5 to 15 mph, with gusts as high as 25 mph.
Mostly Cloudy
then Patchy
Drizzle
 Wednesday

Wednesday: Patchy drizzle before 11am. Partly sunny, with a high near 67. East wind 5 to 15 mph becoming southwest in the afternoon. Winds could gust as high as 25 mph.
Patchy
Drizzle then
Partly Sunny
 Wednesday
Night
Wednesday Night: Patchy drizzle after 2am. Mostly cloudy, with a low around 52. Southwest wind 10 to 15 mph becoming light after midnight. Winds could gust as high as 25 mph.
Mostly Cloudy
then Patchy
Drizzle
 Thursday

Thursday: Patchy drizzle before 11am. Mostly sunny, with a high near 70. Light southwest wind increasing to 10 to 15 mph in the afternoon. Winds could gust as high as 25 mph.
Patchy
Drizzle then
Mostly Sunny
 Thursday
Night
Thursday Night: Partly cloudy, with a low around 53.
Partly Cloudy

 Friday

Friday: Mostly sunny, with a high near 75.
Mostly Sunny

 Friday
Night
Friday Night: Mostly clear, with a low around 55.
Mostly Clear

 Saturday

Saturday: Sunny, with a high near 81.
Sunny
Hi 69 °F Lo 53 °F Hi 67 °F Lo 52 °F Hi 70 °F Lo 53 °F Hi 75 °F Lo 55 °F Hi 81 °F

 

This Afternoon
 
 Mostly sunny, with a high near 69. Southwest wind around 15 mph, with gusts as high as 25 mph.
Tonight
 
 Patchy drizzle after 2am. Increasing clouds, with a low around 53. Southwest wind 5 to 15 mph, with gusts as high as 25 mph.
Wednesday
 
 Patchy drizzle before 11am. Partly sunny, with a high near 67. East wind 5 to 15 mph becoming southwest in the afternoon. Winds could gust as high as 25 mph.
Wednesday Night
 
 Patchy drizzle after 2am. Mostly cloudy, with a low around 52. Southwest wind 10 to 15 mph becoming light after midnight. Winds could gust as high as 25 mph.
Thursday
 
 Patchy drizzle before 11am. Mostly sunny, with a high near 70. Light southwest wind increasing to 10 to 15 mph in the afternoon. Winds could gust as high as 25 mph.
Thursday Night
 
 Partly cloudy, with a low around 53.
Friday
 
 Mostly sunny, with a high near 75.
Friday Night
 
 Mostly clear, with a low around 55.
Saturday
 
 Sunny, with a high near 81.
Saturday Night
 
 Clear, with a low around 58.
Sunday
 
 Sunny, with a high near 86.
Sunday Night
 
 Mostly clear, with a low around 60.
Monday
 
 Sunny, with a high near 89.

 

Forecast from NOAA-NWS for Ontario International Arpt CA.