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

79°F

26°C

Humidity 51%
Wind Speed SSW 7 MPH
Barometer NA
Dewpoint 59°F (15°C)
Visibility NA
Heat Index80°F (27°C)
Last update 21 May 12:57 PM PDT
Extended Forecast for

Diamond Bar CA

  • This Afternoon

    This Afternoon: Sunny, with a high near 82. West southwest wind around 10 mph, with gusts as high as 15 mph.

    High: 82 °F

    Sunny

  • Tonight

    Tonight: Increasing clouds, with a low around 54. Southwest wind 5 to 10 mph becoming light in the evening. Winds could gust as high as 15 mph.

    Low: 54 °F

    Increasing
    Clouds

  • Friday

    Friday: Patchy fog before 11am. Otherwise, cloudy through mid morning, then gradual clearing, with a high near 79. Light south southwest wind becoming southwest 5 to 10 mph in the afternoon. Winds could gust as high as 15 mph.

    High: 79 °F

    Patchy Fog
    then Sunny

  • Friday Night

    Friday Night: Patchy fog after 11pm. Otherwise, increasing clouds, with a low around 53. Southwest wind 5 to 10 mph becoming light in the evening. Winds could gust as high as 15 mph.

    Low: 53 °F

    Patchy Fog

  • Saturday

    Saturday: Patchy fog before 11am. Otherwise, mostly sunny, with a high near 78. Light southwest wind becoming west southwest 5 to 10 mph in the afternoon. Winds could gust as high as 15 mph.

    High: 78 °F

    Patchy Fog
    then Sunny

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 52.

    Low: 52 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny, with a high near 78.

    High: 78 °F

    Sunny

  • Sunday Night

    Sunday Night: Mostly clear, with a low around 53.

    Low: 53 °F

    Mostly Clear

  • Memorial Day

    Memorial Day: Mostly sunny, with a high near 72.

    High: 72 °F

    Mostly Sunny

Detailed Forecast

This Afternoon
Sunny, with a high near 82. West southwest wind around 10 mph, with gusts as high as 15 mph.
Tonight
Increasing clouds, with a low around 54. Southwest wind 5 to 10 mph becoming light in the evening. Winds could gust as high as 15 mph.
Friday
Patchy fog before 11am. Otherwise, cloudy through mid morning, then gradual clearing, with a high near 79. Light south southwest wind becoming southwest 5 to 10 mph in the afternoon. Winds could gust as high as 15 mph.
Friday Night
Patchy fog after 11pm. Otherwise, increasing clouds, with a low around 53. Southwest wind 5 to 10 mph becoming light in the evening. Winds could gust as high as 15 mph.
Saturday
Patchy fog before 11am. Otherwise, mostly sunny, with a high near 78. Light southwest wind becoming west southwest 5 to 10 mph in the afternoon. Winds could gust as high as 15 mph.
Saturday Night
Mostly clear, with a low around 52.
Sunday
Sunny, with a high near 78.
Sunday Night
Mostly clear, with a low around 53.
Memorial Day
Mostly sunny, with a high near 72.
Monday Night
Mostly clear, with a low around 52.
Tuesday
Partly sunny, with a high near 69.
Tuesday Night
Partly cloudy, with a low around 52.
Wednesday
Mostly sunny, with a high near 69.
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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:
12:51 pm PDT May 21, 2026
Forecast Valid:
1pm PDT May 21, 2026-6pm PDT May 27, 2026
 
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