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

Hazardous Weather Conditions

Current conditions at

WHITTIER HILLS (WTHC1)

Lat: 33.984°NLon: 118.00943°WElev: 950.0ft.

NA

78°F

26°C

Humidity 66%
Wind Speed SE 4 MPH
Barometer NA
Dewpoint 66°F (19°C)
Visibility NA
Heat Index80°F (27°C)
Last update 26 Aug 10:57 PM PDT
Extended Forecast for

Diamond Bar CA

Extreme Heat Warning August 26, 11:43pm until August 28, 08:00pm
Click here for hazard details and duration
Extreme Heat Warning
  •  
    Extreme Heat Warning August 26, 11:43pm until August 28, 08:00pm

    NOW until 8:00pm Fri

    Extreme Heat Warning

  • Tonight

    Low: 70 °F

    Mostly Cloudy

  • Thursday

    Thursday: A 20 percent chance of showers and thunderstorms. Mostly cloudy and hot, with a high near 101. Light west wind becoming west southwest 5 to 10 mph in the afternoon.

    High: 101 °F

    Slight Chance
    T-storms

  • Thursday Night

    Thursday Night: A 20 percent chance of showers before 11pm. Mostly cloudy, with a low around 72. West southwest wind 5 to 10 mph becoming light and variable in the evening.

    Low: 72 °F

    Slight Chance
    Showers then
    Mostly Cloudy

  • Friday

    Friday: Partly sunny and hot, with a high near 100. Light and variable wind becoming southwest 5 to 10 mph in the afternoon. Winds could gust as high as 15 mph.

    High: 100 °F

    Hot

  • Friday Night

    Friday Night: Mostly clear, with a low around 71. Southwest wind 5 to 10 mph, with gusts as high as 15 mph.

    Low: 71 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny and hot, with a high near 96.

    High: 96 °F

    Hot

  • Saturday Night

    Saturday Night: Clear, with a low around 67.

    Low: 67 °F

    Clear

  • Sunday

    Sunday: Sunny, with a high near 87.

    High: 87 °F

    Sunny

Detailed Forecast

Tonight
Mostly cloudy, with a low around 70. West southwest wind around 5 mph becoming calm.
Thursday
A 20 percent chance of showers and thunderstorms. Mostly cloudy and hot, with a high near 101. Light west wind becoming west southwest 5 to 10 mph in the afternoon.
Thursday Night
A 20 percent chance of showers before 11pm. Mostly cloudy, with a low around 72. West southwest wind 5 to 10 mph becoming light and variable in the evening.
Friday
Partly sunny and hot, with a high near 100. Light and variable wind becoming southwest 5 to 10 mph in the afternoon. Winds could gust as high as 15 mph.
Friday Night
Mostly clear, with a low around 71. Southwest wind 5 to 10 mph, with gusts as high as 15 mph.
Saturday
Sunny and hot, with a high near 96.
Saturday Night
Clear, with a low around 67.
Sunday
Sunny, with a high near 87.
Sunday Night
Clear, with a low around 64.
Monday
Sunny, with a high near 86.
Monday Night
Mostly clear, with a low around 63.
Tuesday
A slight chance of showers. Mostly sunny, with a high near 86.
Tuesday Night
A slight chance of showers. Partly cloudy, with a low around 64.
Wednesday
A slight chance of showers. Partly sunny, with a high near 87.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Diamond Bar CA
 34°N 117.82°W (Elev. 1014 ft)
Last Update:
11:26 pm PDT Aug 26, 2026
Forecast Valid:
11pm PDT Aug 26, 2026-6pm PDT Sep 2, 2026
 
Forecast Discussion
 
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Additional Resources

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