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

Excessive Rainfall and Potential Tropical Cyclone in the South; Severe Thunderstorms in the Midwest

Excessive rainfall may produce locally considerable flash flooding over parts of the northwestern Gulf Coast, lower Mississippi River Valley, and Deep South through Thursday. Potential Tropical Cyclone One is forecast to become a tropical storm (Arthur) as it moves along or just off the northwestern Gulf coast through Wednesday. An outbreak of severe weather is forecast in the Midwest Wednesday. Read More >

Hazardous Weather Conditions

Current conditions at

Gaithersburg - Montgomery County Airport (KGAI)

Lat: 39.17°NLon: 77.17°WElev: 495ft.

Fair

78°F

26°C

Humidity 35%
Wind Speed Vrbl 5 G 16 mph
Barometer 29.83 in (1011.1 mb)
Dewpoint 48°F (9°C)
Visibility 10.00 mi
Heat Index78°F (26°C)
Last update 16 Jun 5:56 pm EDT
Extended Forecast for

Ashton-Sandy Spring MD

  • Tonight

    Tonight: Increasing clouds, with a low around 62. South wind around 5 mph becoming calm in the evening.

    Low: 62 °F

    Increasing
    Clouds

  • Wednesday

    Wednesday: Mostly sunny, with a high near 85. Calm wind becoming west 5 to 8 mph in the afternoon.

    High: 85 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Mostly cloudy, with a low around 67. Calm wind becoming south 5 to 7 mph after midnight.

    Low: 67 °F

    Mostly Cloudy

  • Thursday

    Thursday: A chance of showers, with thunderstorms also possible after 2pm. Partly sunny, with a high near 91. West wind 13 to 16 mph, with gusts as high as 31 mph. Chance of precipitation is 40%.

    High: 91 °F

    Chance
    Showers then
    Chance
    T-storms

  • Thursday Night

    Thursday Night: A slight chance of showers and thunderstorms before 2am, then a chance of showers between 2am and 5am, then a chance of showers and thunderstorms after 5am. Mostly cloudy, with a low around 67. West wind 6 to 10 mph, with gusts as high as 21 mph. Chance of precipitation is 30%.

    Low: 67 °F

    Slight Chance
    T-storms then
    Chance
    Showers

  • Juneteenth

    Juneteenth: A chance of showers and thunderstorms before 11am, then a chance of showers between 11am and 2pm. Partly sunny, with a high near 81. Chance of precipitation is 40%.

    High: 81 °F

    Chance
    Showers

  • Friday Night

    Friday Night: Mostly clear, with a low around 61.

    Low: 61 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny, with a high near 81.

    High: 81 °F

    Sunny

  • Saturday Night

    Saturday Night: Mostly clear, with a low around 61.

    Low: 61 °F

    Mostly Clear

Detailed Forecast

Tonight
Increasing clouds, with a low around 62. South wind around 5 mph becoming calm in the evening.
Wednesday
Mostly sunny, with a high near 85. Calm wind becoming west 5 to 8 mph in the afternoon.
Wednesday Night
Mostly cloudy, with a low around 67. Calm wind becoming south 5 to 7 mph after midnight.
Thursday
A chance of showers, with thunderstorms also possible after 2pm. Partly sunny, with a high near 91. West wind 13 to 16 mph, with gusts as high as 31 mph. Chance of precipitation is 40%.
Thursday Night
A slight chance of showers and thunderstorms before 2am, then a chance of showers between 2am and 5am, then a chance of showers and thunderstorms after 5am. Mostly cloudy, with a low around 67. West wind 6 to 10 mph, with gusts as high as 21 mph. Chance of precipitation is 30%.
Juneteenth
A chance of showers and thunderstorms before 11am, then a chance of showers between 11am and 2pm. Partly sunny, with a high near 81. Chance of precipitation is 40%.
Friday Night
Mostly clear, with a low around 61.
Saturday
Sunny, with a high near 81.
Saturday Night
Mostly clear, with a low around 61.
Sunday
Sunny, with a high near 83.
Sunday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 63. Chance of precipitation is 40%.
Monday
Showers likely and possibly a thunderstorm. Partly sunny, with a high near 81. Chance of precipitation is 60%.
Monday Night
Showers and thunderstorms likely. Mostly cloudy, with a low around 63. Chance of precipitation is 60%.
Tuesday
A slight chance of showers. Mostly sunny, with a high near 81. Chance of precipitation is 20%.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Ashton-Sandy Spring MD
 39.15°N 77.01°W (Elev. 449 ft)
Last Update:
5:14 pm EDT Jun 16, 2026
Forecast Valid:
6pm EDT Jun 16, 2026-6pm EDT Jun 23, 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