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

Areas of Dangerous Heat and Heavy Rain with Possible Flooding into this Weekend

Hot temperatures and high humidity are forecast to continue across the mid-Mississippi Valley into this weekend with heat advisories in effect. Heavy to excessive rainfall occurring at times through Sunday could bring areas of flooding to parts of the upper Midwest, central Great Lakes, southern New England and Virginia/North Carolina tidewater region. Read More >

Current conditions at

San Francisco, San Francisco International Airport (KSFO)

Lat: 37.61961°NLon: 122.36558°WElev: 10.0ft.

Clear

61°F

16°C

Humidity 82%
Wind Speed WNW 8 MPH
Barometer 30.13 in (1020.32 mb)
Dewpoint 55°F (13°C)
Visibility 10.00 mi
Last update 18 Sep 12:35 AM PDT
Extended Forecast for

San Mateo CA

  • Overnight

    Overnight: Partly cloudy, with a low around 58. Calm wind.

    Low: 58 °F

    Partly Cloudy

  • Friday

    Friday: Partly sunny, then gradually becoming sunny, with a high near 74. Light west wind becoming west northwest 6 to 11 mph in the morning.

    High: 74 °F

    Becoming
    Sunny

  • Friday Night

    Friday Night: Increasing clouds, with a low around 58. West wind 5 to 9 mph becoming light southwest after midnight.

    Low: 58 °F

    Increasing
    Clouds

  • Saturday

    Saturday: Mostly sunny, with a high near 76. Light southwest wind becoming west 5 to 10 mph in the afternoon.

    High: 76 °F

    Mostly Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 58. West wind 6 to 11 mph.

    Low: 58 °F

    Partly Cloudy

  • Sunday

    Sunday: Partly sunny, with a high near 70.

    High: 70 °F

    Partly Sunny

  • Sunday Night

    Sunday Night: Mostly cloudy, with a low around 58.

    Low: 58 °F

    Mostly Cloudy

  • Monday

    Monday: Mostly sunny, with a high near 72.

    High: 72 °F

    Mostly Sunny

  • Monday Night

    Monday Night: Partly cloudy, with a low around 58.

    Low: 58 °F

    Partly Cloudy

Detailed Forecast

Overnight
Partly cloudy, with a low around 58. Calm wind.
Friday
Partly sunny, then gradually becoming sunny, with a high near 74. Light west wind becoming west northwest 6 to 11 mph in the morning.
Friday Night
Increasing clouds, with a low around 58. West wind 5 to 9 mph becoming light southwest after midnight.
Saturday
Mostly sunny, with a high near 76. Light southwest wind becoming west 5 to 10 mph in the afternoon.
Saturday Night
Partly cloudy, with a low around 58. West wind 6 to 11 mph.
Sunday
Partly sunny, with a high near 70.
Sunday Night
Mostly cloudy, with a low around 58.
Monday
Mostly sunny, with a high near 72.
Monday Night
Partly cloudy, with a low around 58.
Tuesday
Mostly sunny, with a high near 76.
Tuesday Night
Mostly clear, with a low around 58.
Wednesday
Sunny, with a high near 82.
Wednesday Night
Mostly clear, with a low around 59.
Thursday
Sunny, with a high near 81.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
San Mateo CA
 37.58°N 122.33°W (Elev. 33 ft)
Last Update:
12:41 am PDT Sep 18, 2026
Forecast Valid:
12am PDT Sep 18, 2026-6pm PDT Sep 24, 2026
 
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Additional Resources

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