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

Thunderstorms and Heavy Rainfall in the Southeast, Montana, and Iowa; Lowell Begins to Impact Hawaii

Strong thunderstorms with damaging winds and heavy rain are expected across portions of the Southeast. Thunderstorms may produce large hail across portions of Montana. Heavy rainfall could produce flash flooding across Iowa and vulnerable areas in Utah. Lowell will bring heavy rain, dangerous swells and rip currents to portions of Hawaii. Sweltering heat persists across the South-Central US. Read More >

Current conditions at

Fort Belvoir (KDAA)

Lat: 38.72°NLon: 77.18°WElev: 69ft.

A Few Clouds

84°F

29°C

Humidity 38%
Wind Speed N 3 mph
Barometer 29.92 in (1013.4 mb)
Dewpoint 56°F (13°C)
Visibility 10.00 mi
Heat Index83°F (28°C)
Last update 6 Sep 2:55 pm EDT
Extended Forecast for

Mount Vernon VA

  • Tonight

    Tonight: Mostly clear, with a low around 63. East wind around 5 mph becoming calm in the evening.

    Low: 63 °F

    Mostly Clear

  • Labor Day

    Labor Day: Mostly sunny, with a high near 84. Light north wind.

    High: 84 °F

    Mostly Sunny

  • Monday Night

    Monday Night: Mostly cloudy, then gradually becoming clear, with a low around 62. Calm wind.

    Low: 62 °F

    Decreasing
    Clouds

  • Tuesday

    Tuesday: Sunny, with a high near 86. Calm wind becoming southwest around 5 mph in the afternoon.

    High: 86 °F

    Sunny

  • Tuesday Night

    Tuesday Night: Partly cloudy, with a low around 64. South wind 3 to 5 mph.

    Low: 64 °F

    Partly Cloudy

  • Wednesday

    Wednesday: Sunny, with a high near 89.

    High: 89 °F

    Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 72.

    Low: 72 °F

    Mostly Clear

  • Thursday

    Thursday: A chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 90. Chance of precipitation is 50%.

    High: 90 °F

    Sunny then
    Chance
    T-storms

  • Thursday Night

    Thursday Night: A chance of showers and thunderstorms before 2am. Mostly cloudy, with a low around 68. Chance of precipitation is 50%.

    Low: 68 °F

    Chance
    T-storms then
    Chance
    Showers

Detailed Forecast

Tonight
Mostly clear, with a low around 63. East wind around 5 mph becoming calm in the evening.
Labor Day
Mostly sunny, with a high near 84. Light north wind.
Monday Night
Mostly cloudy, then gradually becoming clear, with a low around 62. Calm wind.
Tuesday
Sunny, with a high near 86. Calm wind becoming southwest around 5 mph in the afternoon.
Tuesday Night
Partly cloudy, with a low around 64. South wind 3 to 5 mph.
Wednesday
Sunny, with a high near 89.
Wednesday Night
Mostly clear, with a low around 72.
Thursday
A chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 90. Chance of precipitation is 50%.
Thursday Night
A chance of showers and thunderstorms before 2am. Mostly cloudy, with a low around 68. Chance of precipitation is 50%.
Friday
Mostly sunny, with a high near 85.
Friday Night
A slight chance of showers. Partly cloudy, with a low around 65. Chance of precipitation is 20%.
Saturday
A slight chance of showers. Mostly sunny, with a high near 85. Chance of precipitation is 20%.
Saturday Night
A slight chance of showers. Partly cloudy, with a low around 67. Chance of precipitation is 20%.
Sunday
Mostly sunny, with a high near 88.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Mount Vernon VA
 38.72°N 77.08°W (Elev. 13 ft)
Last Update:
2:22 pm EDT Sep 6, 2026
Forecast Valid:
3pm EDT Sep 6, 2026-6pm EDT Sep 13, 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