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

Areas of Extreme Heat and Excessive Rainfall Potential

Dangerous and extreme heat will remain across portions of the central U.S. this week, persisting across the mid to lower Mississippi Valley, Gulf Coast, southern Plains and portions of Texas. A heat wave over the Southwest U.S. will peak this weekend. Heavy to excessive rainfall may produce flash flooding from the Delmarva Peninsula north into the Hudson Valley today and tonight. Read More >

Hazardous Weather Conditions

Current conditions at

Gaithersburg - Montgomery County Airport (KGAI)

Lat: 39.17°NLon: 77.17°WElev: 495ft.

Partly Cloudy

70°F

21°C

Humidity NA
Wind Speed S 3 mph
Barometer 29.59 in (1003.0 mb)
Dewpoint N/A
Visibility 10.00 mi
Last update 28 Jul 6:56 pm EDT
Extended Forecast for

Potomac MD

  • Tonight

    Tonight: Showers likely and possibly a thunderstorm before 8pm, then a chance of showers and thunderstorms between 8pm and 11pm. Some of the storms could be severe. Mostly cloudy, then gradually becoming mostly clear, with a low around 66. Light and variable wind becoming northwest 5 to 8 mph after midnight. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    Low: 66 °F

    Severe
    Thunderstorms
    then Mostly
    Clear

  • Wednesday

    Wednesday: Mostly sunny, with a high near 83. Northwest wind 10 to 13 mph, with gusts as high as 23 mph.

    High: 83 °F

    Mostly Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 66. Northwest wind 8 to 10 mph, with gusts as high as 18 mph.

    Low: 66 °F

    Mostly Clear

  • Thursday

    Thursday: Sunny, with a high near 83. Northwest wind around 11 mph, with gusts as high as 22 mph.

    High: 83 °F

    Sunny

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 65. Northwest wind 3 to 7 mph.

    Low: 65 °F

    Partly Cloudy

  • Friday

    Friday: Sunny, with a high near 86.

    High: 86 °F

    Sunny

  • Friday Night

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

    Low: 69 °F

    Partly Cloudy

  • Saturday

    Saturday: Partly sunny, with a high near 88.

    High: 88 °F

    Partly Sunny

  • Saturday Night

    Saturday Night: A slight chance of showers and thunderstorms before 2am. Mostly cloudy, with a low around 70. Chance of precipitation is 20%.

    Low: 70 °F

    Slight Chance
    T-storms

Detailed Forecast

Tonight
Showers likely and possibly a thunderstorm before 8pm, then a chance of showers and thunderstorms between 8pm and 11pm. Some of the storms could be severe. Mostly cloudy, then gradually becoming mostly clear, with a low around 66. Light and variable wind becoming northwest 5 to 8 mph after midnight. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Wednesday
Mostly sunny, with a high near 83. Northwest wind 10 to 13 mph, with gusts as high as 23 mph.
Wednesday Night
Mostly clear, with a low around 66. Northwest wind 8 to 10 mph, with gusts as high as 18 mph.
Thursday
Sunny, with a high near 83. Northwest wind around 11 mph, with gusts as high as 22 mph.
Thursday Night
Partly cloudy, with a low around 65. Northwest wind 3 to 7 mph.
Friday
Sunny, with a high near 86.
Friday Night
Partly cloudy, with a low around 69.
Saturday
Partly sunny, with a high near 88.
Saturday Night
A slight chance of showers and thunderstorms before 2am. Mostly cloudy, with a low around 70. Chance of precipitation is 20%.
Sunday
A slight chance of showers between 8am and 2pm, then a chance of showers and thunderstorms after 2pm. Mostly cloudy, with a high near 86. Chance of precipitation is 40%.
Sunday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 71. Chance of precipitation is 50%.
Monday
A chance of showers and thunderstorms. Mostly cloudy, with a high near 85. Chance of precipitation is 50%.
Monday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 70. Chance of precipitation is 30%.
Tuesday
A slight chance of showers and thunderstorms. Mostly sunny, with a high near 87. Chance of precipitation is 20%.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Potomac MD
 39.04°N 77.2°W (Elev. 397 ft)
Last Update:
5:28 pm EDT Jul 28, 2026
Forecast Valid:
7pm EDT Jul 28, 2026-6pm EDT Aug 4, 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