National Oceanic and Atmospheric Administration National Weather Service United States Department of Commerce

Severe Thunderstorms in the Midwest and Arizona; Heat Continues in the Southeast and Southwest

Thunderstorms, some severe, may lead to scattered instances of flash flooding across the Midwest and Ohio Valley and southern Arizona. The threat will shift to the Mid-Atlantic coast on Thursday. Dangerous heat persists in the South and Southeast while building into the Southwest. Overnight lows will be so warm that little-to-no relief from the scorching daytime highs will be available. Read More >

Hazardous Weather Conditions

Current conditions at

Ontario Municipal Airport (KONO)

Lat: 44.01424°NLon: 117.00808°WElev: 2185.0ft.

Clear

66°F

19°C

Humidity 63%
Wind Speed W 3 MPH
Barometer 29.9 in (1012.53 mb)
Dewpoint 54°F (12°C)
Visibility 10.00 mi
Last update 19 Aug 11:35 PM MDT
Extended Forecast for

4 Miles N Ontario Municipal OR

Heat Advisory August 20, 12:00pm until August 21, 09:00pm
Click here for hazard details and duration
Heat Advisory

  • Tonight

    Tonight: Mostly clear, with a low around 63. North northwest wind 3 to 7 mph.

    Low: 63 °F

    Mostly Clear

  • Thursday

    Thursday: Sunny and hot, with a high near 99. Light and variable wind.

    High: 99 °F

    Hot

  • Thursday Night

    Thursday Night: Patchy smoke between 2am and 5am. Increasing clouds, with a low around 66. Calm wind becoming northwest 5 to 8 mph after midnight.

    Low: 66 °F

    Mostly Cloudy
    then Patchy
    Smoke

  • Friday

    Friday: Patchy smoke between 7am and 11am. Partly sunny and hot, with a high near 100. Light and variable wind.

    High: 100 °F

    Patchy Smoke
    then Partly
    Sunny

  • Friday Night

    Friday Night: Mostly cloudy, with a low around 70. Calm wind becoming northwest 5 to 7 mph.

    Low: 70 °F

    Mostly Cloudy

  • Saturday

    Saturday: Partly sunny and hot, with a high near 96.

    High: 96 °F

    Hot

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 64.

    Low: 64 °F

    Partly Cloudy

  • Sunday

    Sunday: Sunny and hot, with a high near 90.

    High: 90 °F

    Hot

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 60.

    Low: 60 °F

    Mostly Clear

Detailed Forecast

Tonight
Mostly clear, with a low around 63. North northwest wind 3 to 7 mph.
Thursday
Sunny and hot, with a high near 99. Light and variable wind.
Thursday Night
Patchy smoke between 2am and 5am. Increasing clouds, with a low around 66. Calm wind becoming northwest 5 to 8 mph after midnight.
Friday
Patchy smoke between 7am and 11am. Partly sunny and hot, with a high near 100. Light and variable wind.
Friday Night
Mostly cloudy, with a low around 70. Calm wind becoming northwest 5 to 7 mph.
Saturday
Partly sunny and hot, with a high near 96.
Saturday Night
Partly cloudy, with a low around 64.
Sunday
Sunny and hot, with a high near 90.
Sunday Night
Mostly clear, with a low around 60.
Monday
Mostly sunny and hot, with a high near 92.
Monday Night
Partly cloudy, with a low around 63.
Tuesday
Mostly sunny and hot, with a high near 94.
Tuesday Night
Partly cloudy, with a low around 64.
Wednesday
Mostly sunny and hot, with a high near 92.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
4 Miles N Ontario Municipal OR
 44.07°N 117.01°W (Elev. 2251 ft)
Last Update:
12:32 pm MDT Aug 19, 2026
Forecast Valid:
11pm MDT Aug 19, 2026-6pm MDT Aug 26, 2026
 
Forecast Discussion
 
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Additional Resources

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