National Weather Service Forecast for: Ontario International Arpt CA
Issued by: National Weather Service San Diego, CA
Updated: 8:38 pm PDT Jun 29, 2026
 
Tonight

Tonight: Patchy drizzle after 2am. Patchy fog between 11pm and 2am. Otherwise, increasing clouds, with a low around 58. West wind 5 to 10 mph, with gusts as high as 20 mph.
Patchy Fog
then Patchy
Drizzle and
Patchy Fog
 Tuesday

Tuesday: Patchy drizzle before 11am. Mostly cloudy through mid morning, then gradual clearing, with a high near 78. West wind 5 to 15 mph, with gusts as high as 20 mph.
Patchy
Drizzle then
Sunny
 Tuesday
Night
Tuesday Night: Increasing clouds, with a low around 57. West wind 5 to 10 mph, with gusts as high as 20 mph.
Increasing
Clouds

 Wednesday

Wednesday: Patchy fog before 11am. Otherwise, mostly cloudy through mid morning, then gradual clearing, with a high near 81. Light and variable wind becoming west 10 to 15 mph in the afternoon. Winds could gust as high as 20 mph.
Patchy Fog
then Sunny

 Wednesday
Night
Wednesday Night: Mostly clear, with a low around 57. Southwest wind 10 to 15 mph becoming light west after midnight. Winds could gust as high as 20 mph.
Mostly Clear

 Thursday

Thursday: Sunny, with a high near 84.
Sunny

 Thursday
Night
Thursday Night: Mostly clear, with a low around 59.
Mostly Clear

 Friday

Friday: Sunny, with a high near 86.
Sunny

 Friday
Night
Friday Night: Mostly clear, with a low around 60.
Mostly Clear
Lo 58 °F Hi 78 °F Lo 57 °F Hi 81 °F Lo 57 °F Hi 84 °F Lo 59 °F Hi 86 °F Lo 60 °F

 

Tonight
 
 Patchy drizzle after 2am. Patchy fog between 11pm and 2am. Otherwise, increasing clouds, with a low around 58. West wind 5 to 10 mph, with gusts as high as 20 mph.
Tuesday
 
 Patchy drizzle before 11am. Mostly cloudy through mid morning, then gradual clearing, with a high near 78. West wind 5 to 15 mph, with gusts as high as 20 mph.
Tuesday Night
 
 Increasing clouds, with a low around 57. West wind 5 to 10 mph, with gusts as high as 20 mph.
Wednesday
 
 Patchy fog before 11am. Otherwise, mostly cloudy through mid morning, then gradual clearing, with a high near 81. Light and variable wind becoming west 10 to 15 mph in the afternoon. Winds could gust as high as 20 mph.
Wednesday Night
 
 Mostly clear, with a low around 57. Southwest wind 10 to 15 mph becoming light west after midnight. Winds could gust as high as 20 mph.
Thursday
 
 Sunny, with a high near 84.
Thursday Night
 
 Mostly clear, with a low around 59.
Friday
 
 Sunny, with a high near 86.
Friday Night
 
 Mostly clear, with a low around 60.
Independence Day
 
 Mostly sunny, with a high near 89.
Saturday Night
 
 Mostly clear, with a low around 61.
Sunday
 
 Sunny, with a high near 89.
Sunday Night
 
 Mostly clear, with a low around 62.
Monday
 
 Sunny, with a high near 90.

 

Forecast from NOAA-NWS for Ontario International Arpt CA.