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

Hazardous Weather Conditions

Current conditions at

FW0063 Fullerton CSU (F0063)

Lat: 33.8805°NLon: 117.88417°WElev: 243.01ft.

NA

79°F

26°C

Humidity 71%
Wind Speed NW 1 MPH
Barometer 30.01 in (1016.26 mb)
Dewpoint 69°F (21°C)
Visibility NA
Heat Index81°F (27°C)
Last update 25 Aug 08:53 AM PDT
Extended Forecast for

Fullerton CA

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

    NOW until 8:00pm Fri

    Extreme Heat Warning

  • Today

    High: 99 °F

    Sunny

  • Tonight

    Tonight: Mostly clear, with a low around 72. South wind around 5 mph becoming calm in the evening.

    Low: 72 °F

    Mostly Clear

  • Wednesday

    Wednesday: Sunny, with a high near 101. Heat index values as high as 105. Light southwest wind increasing to 5 to 10 mph in the afternoon.

    High: 101 °F

    Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 76. South wind around 5 mph becoming calm in the evening.

    Low: 76 °F

    Mostly Clear

  • Thursday

    Thursday: Patchy fog before 11am. Otherwise, mostly sunny, with a high near 104. Light and variable wind becoming southwest 5 to 10 mph in the afternoon.

    High: 104 °F

    Patchy Fog
    then Mostly
    Sunny

  • Thursday Night

    Thursday Night: Patchy fog after 11pm. Otherwise, partly cloudy, with a low around 77.

    Low: 77 °F

    Patchy Fog

  • Friday

    Friday: Patchy fog before 11am. Otherwise, mostly sunny, with a high near 104.

    High: 104 °F

    Patchy Fog
    then Mostly
    Sunny

  • Friday Night

    Friday Night: Partly cloudy, with a low around 75.

    Low: 75 °F

    Partly Cloudy

Detailed Forecast

Today
Sunny, with a high near 99. Light southwest wind increasing to 5 to 10 mph in the afternoon.
Tonight
Mostly clear, with a low around 72. South wind around 5 mph becoming calm in the evening.
Wednesday
Sunny, with a high near 101. Heat index values as high as 105. Light southwest wind increasing to 5 to 10 mph in the afternoon.
Wednesday Night
Mostly clear, with a low around 76. South wind around 5 mph becoming calm in the evening.
Thursday
Patchy fog before 11am. Otherwise, mostly sunny, with a high near 104. Light and variable wind becoming southwest 5 to 10 mph in the afternoon.
Thursday Night
Patchy fog after 11pm. Otherwise, partly cloudy, with a low around 77.
Friday
Patchy fog before 11am. Otherwise, mostly sunny, with a high near 104.
Friday Night
Partly cloudy, with a low around 75.
Saturday
Sunny, with a high near 95.
Saturday Night
Mostly clear, with a low around 71.
Sunday
Sunny, with a high near 90.
Sunday Night
Mostly clear, with a low around 68.
Monday
Sunny, with a high near 88.
Basemap Options
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Fullerton CA
 33.87°N 117.91°W (Elev. 184 ft)
Last Update:
3:55 am PDT Aug 25, 2026
Forecast Valid:
9am PDT Aug 25, 2026-6pm PDT Aug 31, 2026
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

Link to Local Radar Data Link to Satellite Data

Hourly Weather Forecast

National Digital Forecast Database

National Digital Forecast Database Maximum Temperature Forecast

High Temperature

National Digital Forecast Database Weather Element Forecast

Chance of Precipitation