Severe Thunderstorms and Flooding from the Southern Plains to the Great Lakes; Record Heat in the East

Widely scattered severe thunderstorms may produce damaging winds, hail, and flash flooding from the southern Plains into the lower Great Lakes. Elevated to locally critical fire weather conditions will persist across portions of the Southwest and Southern High Plains due to gusty winds and dry conditions. An early-season heatwave will challenge temperature records across the eastern U.S.. Read More >

Current conditions at

Napa, Napa County Airport (KAPC)

Lat: 38.2075°NLon: 122.27944°WElev: 33.0ft.

Clear

59°F

15°C

Humidity 82%
Wind Speed S 5 MPH
Barometer 29.97 in (1014.9 mb)
Dewpoint 54°F (12°C)
Visibility 10.00 mi
Last update 20 May 01:00 AM PDT
Extended Forecast for

4 Miles E Saint Helena CA

  • Overnight

    Overnight: Mostly clear, with a low around 55. Calm wind.

    Low: 55 °F

    Mostly Clear

  • Wednesday

    Wednesday: Sunny, with a high near 88. Calm wind becoming south southwest around 6 mph in the afternoon.

    High: 88 °F

    Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 53. Light and variable wind.

    Low: 53 °F

    Mostly Clear

  • Thursday

    Thursday: Sunny, with a high near 91. Calm wind becoming southwest around 6 mph in the afternoon.

    High: 91 °F

    Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 52. West southwest wind 5 to 7 mph becoming calm  in the evening.

    Low: 52 °F

    Mostly Clear

  • Friday

    Friday: Sunny, with a high near 85.

    High: 85 °F

    Sunny

  • Friday Night

    Friday Night: Patchy fog after 3am.  Otherwise, mostly clear, with a low around 50.

    Low: 50 °F

    Clear then
    Patchy Fog

  • Saturday

    Saturday: Patchy fog before 8am.  Otherwise, sunny, with a high near 78.

    High: 78 °F

    Patchy Fog
    then Sunny

  • Saturday Night

    Saturday Night: Patchy fog after 2am.  Otherwise, mostly clear, with a low around 48.

    Low: 48 °F

    Clear then
    Patchy Fog

Detailed Forecast

Overnight
Mostly clear, with a low around 55. Calm wind.
Wednesday
Sunny, with a high near 88. Calm wind becoming south southwest around 6 mph in the afternoon.
Wednesday Night
Mostly clear, with a low around 53. Light and variable wind.
Thursday
Sunny, with a high near 91. Calm wind becoming southwest around 6 mph in the afternoon.
Thursday Night
Mostly clear, with a low around 52. West southwest wind 5 to 7 mph becoming calm in the evening.
Friday
Sunny, with a high near 85.
Friday Night
Patchy fog after 3am. Otherwise, mostly clear, with a low around 50.
Saturday
Patchy fog before 8am. Otherwise, sunny, with a high near 78.
Saturday Night
Patchy fog after 2am. Otherwise, mostly clear, with a low around 48.
Sunday
Patchy fog before 7am. Otherwise, sunny, with a high near 79.
Sunday Night
Patchy fog. Otherwise, mostly clear, with a low around 48.
Memorial Day
Patchy fog. Otherwise, mostly sunny, with a high near 80.
Monday Night
Mostly clear, with a low around 48.
Tuesday
Sunny, with a high near 77.
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ABOUT THIS FORECAST

 
Point Forecast:
4 Miles E Saint Helena CA
 38.5°N 122.4°W (Elev. 476 ft)
1:12 am PDT May 20, 2026
1am PDT May 20, 2026-6pm PDT May 26, 2026
 
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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