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

WHITTIER HILLS (WTHC1)

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

NA

79°F

26°C

Humidity 45%
Wind Speed SSW 7 MPH
Barometer NA
Dewpoint 56°F (13°C)
Visibility NA
Heat Index80°F (27°C)
Last update 12 Nov 12:57 PM PST
Extended Forecast for

Diamond Bar CA

  • This Afternoon

    This Afternoon: Mostly sunny, with a high near 79. South southwest wind around 5 mph.

    High: 79 °F

    Mostly Sunny

  • Tonight

    Tonight: Rain likely, mainly after 4am. Mostly cloudy, with a low around 60. South southwest wind around 5 mph becoming southeast after midnight. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.

    Low: 60 °F

    Chance Rain
    then Rain
    Likely

  • Friday

    Friday: Rain likely, mainly before 10am. Mostly cloudy, with a high near 71. Southwest wind 5 to 10 mph. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.

    High: 71 °F

    Rain Likely
    then Chance
    Rain

  • Friday Night

    Friday Night: Rain, mainly between 10pm and 4am. Low around 58. Southwest wind 5 to 10 mph. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.

    Low: 58 °F

    Rain

  • Saturday

    Saturday: A 40 percent chance of rain before 10am. Mostly sunny, with a high near 69. South southwest wind around 5 mph. New precipitation amounts of less than a tenth of an inch possible.

    High: 69 °F

    Chance Rain
    then Mostly
    Sunny

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 56.

    Low: 56 °F

    Mostly Clear

  • Sunday

    Sunday: Sunny, with a high near 71.

    High: 71 °F

    Sunny

  • Sunday Night

    Sunday Night: A slight chance of rain after 4am. Mostly cloudy, with a low around 53.

    Low: 53 °F

    Partly Cloudy
    then Slight
    Chance Rain

  • Monday

    Monday: Rain likely, mainly after 4pm. Mostly cloudy, with a high near 67.

    High: 67 °F

    Rain Likely

Detailed Forecast

This Afternoon
Mostly sunny, with a high near 79. South southwest wind around 5 mph.
Tonight
Rain likely, mainly after 4am. Mostly cloudy, with a low around 60. South southwest wind around 5 mph becoming southeast after midnight. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch possible.
Friday
Rain likely, mainly before 10am. Mostly cloudy, with a high near 71. Southwest wind 5 to 10 mph. Chance of precipitation is 60%. New precipitation amounts between a tenth and quarter of an inch possible.
Friday Night
Rain, mainly between 10pm and 4am. Low around 58. Southwest wind 5 to 10 mph. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.
Saturday
A 40 percent chance of rain before 10am. Mostly sunny, with a high near 69. South southwest wind around 5 mph. New precipitation amounts of less than a tenth of an inch possible.
Saturday Night
Mostly clear, with a low around 56.
Sunday
Sunny, with a high near 71.
Sunday Night
A slight chance of rain after 4am. Mostly cloudy, with a low around 53.
Monday
Rain likely, mainly after 4pm. Mostly cloudy, with a high near 67.
Monday Night
Rain, mainly before 4am. Mostly cloudy, with a low around 51.
Tuesday
A chance of rain. Mostly sunny, with a high near 64.
Tuesday Night
Mostly clear, with a low around 48.
Wednesday
Sunny, with a high near 66.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Diamond Bar CA
 34°N 117.82°W (Elev. 1014 ft)
Last Update:
1:52 pm PST Nov 12, 2026
Forecast Valid:
1pm PST Nov 12, 2026-6pm PST Nov 18, 2026
 
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Additional Resources

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Hourly Weather Forecast

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High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation