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

Severe Weather and Heavy Rainfall from the Midwest to the Ohio Valley; Mid-Summer Heat Continues

Severe thunderstorm and heavy rainfall threats will persist from the Midwest to Lower Great Lakes through Monday, shifting into the Ohio Valley and Central Appalachians Monday evening into Tuesday. Mid-summer heat will continue across much of the CONUS this week, with record highs possible well into the 100s across the south-central High Plains. Read More >

Current conditions at

Gaithersburg - Montgomery County Airport (KGAI)

Lat: 39.17°NLon: 77.17°WElev: 495ft.

Fair

78°F

26°C

Humidity 76%
Wind Speed Calm
Barometer 30.03 in (1017.9 mb)
Dewpoint 70°F (21°C)
Visibility 10.00 mi
Heat Index80°F (27°C)
Last update 9 Aug 8:56 pm EDT
Extended Forecast for

Potomac MD

  • Tonight

    Tonight: Mostly clear, with a low around 72. Calm wind.

    Low: 72 °F

    Mostly Clear

  • Monday

    Monday: A chance of showers and thunderstorms after 3pm. Mostly sunny, with a high near 93. Calm wind becoming southwest 5 to 8 mph in the afternoon. Chance of precipitation is 30%.

    High: 93 °F

    Sunny then
    Chance
    T-storms

  • Monday Night

    Monday Night: A chance of showers and thunderstorms before 8pm. Mostly cloudy, with a low around 74. West wind around 5 mph becoming calm in the evening. Chance of precipitation is 30%.

    Low: 74 °F

    Chance
    T-storms then
    Mostly Cloudy

  • Tuesday

    Tuesday: Showers likely and possibly a thunderstorm after 2pm. Partly sunny, with a high near 88. West wind 3 to 8 mph. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    High: 88 °F

    Partly Sunny
    then Showers
    Likely

  • Tuesday Night

    Tuesday Night: Showers likely and possibly a thunderstorm before 8pm, then a chance of showers and thunderstorms between 8pm and 2am, then a slight chance of showers after 2am. Mostly cloudy, with a low around 70. West wind around 6 mph becoming calm in the evening. Chance of precipitation is 60%.

    Low: 70 °F

    Showers
    Likely

  • Wednesday

    Wednesday: A slight chance of showers before 8am, then a chance of showers and thunderstorms after 2pm. Partly sunny, with a high near 87. Chance of precipitation is 40%.

    High: 87 °F

    Mostly Sunny
    then Chance
    T-storms

  • Wednesday Night

    Wednesday Night: A chance of showers and thunderstorms before 2am, then a slight chance of showers. Mostly cloudy, with a low around 70. Chance of precipitation is 50%.

    Low: 70 °F

    Chance
    T-storms then
    Chance
    Showers

  • Thursday

    Thursday: A slight chance of showers before 8am, then a slight chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 88. Chance of precipitation is 20%.

    High: 88 °F

    Mostly Sunny
    then Slight
    Chance
    T-storms

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 69.

    Low: 69 °F

    Partly Cloudy

Detailed Forecast

Tonight
Mostly clear, with a low around 72. Calm wind.
Monday
A chance of showers and thunderstorms after 3pm. Mostly sunny, with a high near 93. Calm wind becoming southwest 5 to 8 mph in the afternoon. Chance of precipitation is 30%.
Monday Night
A chance of showers and thunderstorms before 8pm. Mostly cloudy, with a low around 74. West wind around 5 mph becoming calm in the evening. Chance of precipitation is 30%.
Tuesday
Showers likely and possibly a thunderstorm after 2pm. Partly sunny, with a high near 88. West wind 3 to 8 mph. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Tuesday Night
Showers likely and possibly a thunderstorm before 8pm, then a chance of showers and thunderstorms between 8pm and 2am, then a slight chance of showers after 2am. Mostly cloudy, with a low around 70. West wind around 6 mph becoming calm in the evening. Chance of precipitation is 60%.
Wednesday
A slight chance of showers before 8am, then a chance of showers and thunderstorms after 2pm. Partly sunny, with a high near 87. Chance of precipitation is 40%.
Wednesday Night
A chance of showers and thunderstorms before 2am, then a slight chance of showers. Mostly cloudy, with a low around 70. Chance of precipitation is 50%.
Thursday
A slight chance of showers before 8am, then a slight chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 88. Chance of precipitation is 20%.
Thursday Night
Partly cloudy, with a low around 69.
Friday
A slight chance of showers after 2pm. Mostly sunny, with a high near 82. Chance of precipitation is 20%.
Friday Night
A slight chance of showers. Partly cloudy, with a low around 66. Chance of precipitation is 20%.
Saturday
A slight chance of showers. Mostly sunny, with a high near 82. Chance of precipitation is 20%.
Saturday Night
A slight chance of showers. Partly cloudy, with a low around 66. Chance of precipitation is 20%.
Sunday
A chance of showers and thunderstorms. Mostly sunny, with a high near 84. Chance of precipitation is 30%.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Potomac MD
 39.02°N 77.2°W (Elev. 381 ft)
Last Update:
9:32 pm EDT Aug 9, 2026
Forecast Valid:
9pm EDT Aug 9, 2026-6pm EDT Aug 16, 2026
 
Forecast Discussion
 
Get as KML Get as XML

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