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

Dangerous Heat and Heavy Rainfall into the Weekend

Hot temperatures and high humidity are forecast to continue across the mid-Mississippi Valley into this weekend. Heat Advisories remain in effect. Heavy to excessive rainfall occurring at times through the weekend could bring areas of flooding to parts of the northern Rockies, upper Midwest, central Great Lakes, and southern New England. Read More >

Current conditions at

Gaithersburg - Montgomery County Airport (KGAI)

Lat: 39.17°NLon: 77.17°WElev: 495ft.

Overcast

66°F

19°C

Humidity 93%
Wind Speed Calm
Barometer 30.15 in (1021.9 mb)
Dewpoint 64°F (18°C)
Visibility 10.00 mi
Last update 19 Sep 12:56 am EDT
Extended Forecast for

Gaithersburg MD

  • Overnight

    Overnight: Mostly cloudy, with a low around 60. Northeast wind around 9 mph.

    Low: 60 °F

    Mostly Cloudy

  • Saturday

    Saturday: Partly sunny, with a high near 78. Northeast wind 7 to 9 mph.

    High: 78 °F

    Partly Sunny

  • Saturday Night

    Saturday Night: Isolated showers after 2am. Mostly cloudy, with a low around 66. Southeast wind around 8 mph. Chance of precipitation is 20%.

    Low: 66 °F

    Mostly Cloudy
    then Isolated
    Showers

  • Sunday

    Sunday: Showers likely, with thunderstorms also possible after 5pm. Mostly cloudy, with a high near 82. South wind 8 to 13 mph. Chance of precipitation is 60%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    High: 82 °F

    Mostly Cloudy
    then Showers
    Likely

  • Sunday Night

    Sunday Night: Showers likely and possibly a thunderstorm before 2am, then a slight chance of showers. Mostly cloudy, with a low around 64. Southwest wind around 6 mph becoming north after midnight. Chance of precipitation is 70%.

    Low: 64 °F

    Showers
    Likely

  • Monday

    Monday: A chance of showers, mainly after 2pm. Partly sunny, with a high near 73. Chance of precipitation is 40%.

    High: 73 °F

    Chance
    Showers

  • Monday Night

    Monday Night: A chance of showers. Mostly cloudy, with a low around 60. Chance of precipitation is 50%.

    Low: 60 °F

    Chance
    Showers

  • Tuesday

    Tuesday: Showers likely. Mostly cloudy, with a high near 65. Chance of precipitation is 60%.

    High: 65 °F

    Showers
    Likely

  • Tuesday Night

    Tuesday Night: A chance of showers. Mostly cloudy, with a low around 55. Chance of precipitation is 50%.

    Low: 55 °F

    Chance
    Showers

Detailed Forecast

Overnight
Mostly cloudy, with a low around 60. Northeast wind around 9 mph.
Saturday
Partly sunny, with a high near 78. Northeast wind 7 to 9 mph.
Saturday Night
Isolated showers after 2am. Mostly cloudy, with a low around 66. Southeast wind around 8 mph. Chance of precipitation is 20%.
Sunday
Showers likely, with thunderstorms also possible after 5pm. Mostly cloudy, with a high near 82. South wind 8 to 13 mph. Chance of precipitation is 60%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Sunday Night
Showers likely and possibly a thunderstorm before 2am, then a slight chance of showers. Mostly cloudy, with a low around 64. Southwest wind around 6 mph becoming north after midnight. Chance of precipitation is 70%.
Monday
A chance of showers, mainly after 2pm. Partly sunny, with a high near 73. Chance of precipitation is 40%.
Monday Night
A chance of showers. Mostly cloudy, with a low around 60. Chance of precipitation is 50%.
Tuesday
Showers likely. Mostly cloudy, with a high near 65. Chance of precipitation is 60%.
Tuesday Night
A chance of showers. Mostly cloudy, with a low around 55. Chance of precipitation is 50%.
Wednesday
A chance of showers, with thunderstorms also possible after 2pm. Mostly cloudy, with a high near 61. Chance of precipitation is 50%.
Wednesday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 55. Chance of precipitation is 50%.
Thursday
A chance of showers and thunderstorms. Mostly cloudy, with a high near 63. Chance of precipitation is 40%.
Thursday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 54. Chance of precipitation is 30%.
Friday
A slight chance of showers. Partly sunny, with a high near 68. Chance of precipitation is 20%.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Gaithersburg MD
 39.13°N 77.21°W (Elev. 404 ft)
Last Update:
10:53 pm EDT Sep 18, 2026
Forecast Valid:
1am EDT Sep 19, 2026-6pm EDT Sep 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