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

Tropical Storm Arthur and Heavy Rainfall in the South; Severe Weather in the Midwest

An outbreak of severe thunderstorms is expected across portions of Illinois and Indiana tonight. Intense tornadoes, swaths of damaging gusts, and hail in excess of 2 inches in diameter possible. Tropical Storm Arthur will continue to produce strong winds across coastal Upper Texas and Louisiana tonight, as well as potentially life-threatening flooding across southern Louisiana into Mississippi. Read More >

Current conditions at

Gaithersburg - Montgomery County Airport (KGAI)

Lat: 39.17°NLon: 77.17°WElev: 495ft.

Fair

77°F

25°C

Humidity 58%
Wind Speed SE 9 mph
Barometer 29.76 in (1008.5 mb)
Dewpoint 61°F (16°C)
Visibility 10.00 mi
Heat Index79°F (26°C)
Last update 17 Jun 9:56 pm EDT
Extended Forecast for

Ashton-Sandy Spring MD

  • Tonight

    Tonight: Mostly cloudy, with a low around 70. South wind 6 to 8 mph, with gusts as high as 20 mph.

    Low: 70 °F

    Mostly Cloudy

  • Thursday

    Thursday: A slight chance of showers, then a chance of showers and thunderstorms after 2pm. Partly sunny, with a high near 91. Breezy, with a southwest wind 15 to 21 mph, with gusts as high as 33 mph. Chance of precipitation is 40%.

    High: 91 °F

    Breezy.
    Slight Chance
    Showers then
    Chance
    T-storms

  • Thursday Night

    Thursday Night: Mostly cloudy, with a low around 67. West wind 5 to 10 mph, with gusts as high as 22 mph.

    Low: 67 °F

    Mostly Cloudy

  • Juneteenth

    Juneteenth: Mostly cloudy, then gradually becoming sunny, with a high near 82. West wind 6 to 11 mph, with gusts as high as 21 mph.

    High: 82 °F

    Decreasing
    Clouds

  • Friday Night

    Friday Night: Mostly clear, with a low around 62. Northwest wind 5 to 9 mph becoming light west after midnight. Winds could gust as high as 18 mph.

    Low: 62 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny, with a high near 82.

    High: 82 °F

    Sunny

  • Saturday Night

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

    Low: 61 °F

    Mostly Clear

  • Sunday

    Sunday: Mostly sunny, with a high near 84.

    High: 84 °F

    Mostly Sunny

  • Sunday Night

    Sunday Night: A chance of showers and thunderstorms. Mostly cloudy, with a low around 64. Chance of precipitation is 50%.

    Low: 64 °F

    Chance
    Showers

Detailed Forecast

Tonight
Mostly cloudy, with a low around 70. South wind 6 to 8 mph, with gusts as high as 20 mph.
Thursday
A slight chance of showers, then a chance of showers and thunderstorms after 2pm. Partly sunny, with a high near 91. Breezy, with a southwest wind 15 to 21 mph, with gusts as high as 33 mph. Chance of precipitation is 40%.
Thursday Night
Mostly cloudy, with a low around 67. West wind 5 to 10 mph, with gusts as high as 22 mph.
Juneteenth
Mostly cloudy, then gradually becoming sunny, with a high near 82. West wind 6 to 11 mph, with gusts as high as 21 mph.
Friday Night
Mostly clear, with a low around 62. Northwest wind 5 to 9 mph becoming light west after midnight. Winds could gust as high as 18 mph.
Saturday
Sunny, with a high near 82.
Saturday Night
Mostly clear, with a low around 61.
Sunday
Mostly sunny, with a high near 84.
Sunday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 64. Chance of precipitation is 50%.
Monday
Showers likely, with thunderstorms also possible after 2pm. Mostly cloudy, with a high near 83. Chance of precipitation is 70%.
Monday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 62. Chance of precipitation is 30%.
Tuesday
A slight chance of showers and thunderstorms. Sunny, with a high near 82. Chance of precipitation is 20%.
Tuesday Night
Mostly clear, with a low around 62.
Wednesday
Mostly sunny, with a high near 82.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Ashton-Sandy Spring MD
 39.15°N 77.01°W (Elev. 449 ft)
Last Update:
10:53 pm EDT Jun 17, 2026
Forecast Valid:
10pm EDT Jun 17, 2026-6pm EDT Jun 24, 2026
 
Forecast Discussion
 
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Additional Resources

Radar & Satellite Image

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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