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

Gaithersburg - Montgomery County Airport (KGAI)

Lat: 39.17°NLon: 77.17°WElev: 495ft.

Fair

66°F

19°C

Humidity NA
Wind Speed Calm
Barometer 29.96 in (1015.5 mb)
Dewpoint N/A
Visibility 10.00 mi
Last update 18 Aug 11:56 pm EDT
Extended Forecast for

Potomac MD

  • Overnight

    Overnight: Mostly clear, with a low around 67. Calm wind.

    Low: 67 °F

    Mostly Clear

  • Wednesday

    Wednesday: Patchy fog before 8am. Otherwise, sunny, with a high near 88. Calm wind becoming west around 5 mph in the afternoon.

    High: 88 °F

    Patchy Fog
    then Sunny

  • Wednesday Night

    Wednesday Night: Partly cloudy, with a low around 71. Calm wind.

    Low: 71 °F

    Partly Cloudy

  • Thursday

    Thursday: Showers and thunderstorms likely, mainly before 4pm, then showers likely and possibly a thunderstorm after 5pm. Increasing clouds, with a high near 84. Calm wind becoming southwest around 6 mph in the afternoon. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    High: 84 °F

    Slight Chance
    Showers then
    Showers
    Likely

  • Thursday Night

    Thursday Night: Showers and thunderstorms likely before 8pm, then a slight chance of showers between 8pm and 2am. Mostly cloudy, with a low around 66. Light north wind. Chance of precipitation is 60%.

    Low: 66 °F

    Showers
    Likely then
    Slight Chance
    Showers

  • Friday

    Friday: A chance of showers, with thunderstorms also possible after 5pm. Mostly sunny, with a high near 83. Chance of precipitation is 30%.

    High: 83 °F

    Chance
    Showers

  • Friday Night

    Friday Night: A chance of showers and thunderstorms. Mostly cloudy, with a low around 67. Chance of precipitation is 50%.

    Low: 67 °F

    Chance
    T-storms then
    Chance
    Showers

  • Saturday

    Saturday: A chance of showers, with thunderstorms also possible after 2pm. Mostly cloudy, with a high near 83. Chance of precipitation is 50%.

    High: 83 °F

    Chance
    Showers

  • Saturday Night

    Saturday Night: A chance of showers and thunderstorms before 2am, then a slight chance of showers. Mostly cloudy, with a low around 67. Chance of precipitation is 50%.

    Low: 67 °F

    Chance
    Showers

Detailed Forecast

Overnight
Mostly clear, with a low around 67. Calm wind.
Wednesday
Patchy fog before 8am. Otherwise, sunny, with a high near 88. Calm wind becoming west around 5 mph in the afternoon.
Wednesday Night
Partly cloudy, with a low around 71. Calm wind.
Thursday
Showers and thunderstorms likely, mainly before 4pm, then showers likely and possibly a thunderstorm after 5pm. Increasing clouds, with a high near 84. Calm wind becoming southwest around 6 mph in the afternoon. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Thursday Night
Showers and thunderstorms likely before 8pm, then a slight chance of showers between 8pm and 2am. Mostly cloudy, with a low around 66. Light north wind. Chance of precipitation is 60%.
Friday
A chance of showers, with thunderstorms also possible after 5pm. Mostly sunny, with a high near 83. Chance of precipitation is 30%.
Friday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 67. Chance of precipitation is 50%.
Saturday
A chance of showers, with thunderstorms also possible after 2pm. Mostly cloudy, with a high near 83. Chance of precipitation is 50%.
Saturday Night
A chance of showers and thunderstorms before 2am, then a slight chance of showers. Mostly cloudy, with a low around 67. Chance of precipitation is 50%.
Sunday
A slight chance of showers before 8am, then a chance of showers and thunderstorms after 2pm. Partly sunny, with a high near 83. Chance of precipitation is 30%.
Sunday Night
A chance of showers and thunderstorms. Partly cloudy, with a low around 64. Chance of precipitation is 30%.
Monday
Sunny, with a high near 83.
Monday Night
Partly cloudy, with a low around 65.
Tuesday
A slight chance of showers. Mostly sunny, with a high near 84. Chance of precipitation is 20%.
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ABOUT THIS FORECAST

 
Point Forecast:
Potomac MD
 39.02°N 77.23°W (Elev. 322 ft)
Last Update:
12:05 am EDT Aug 19, 2026
Forecast Valid:
12am EDT Aug 19, 2026-6pm EDT Aug 25, 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