Dangerous Heat Wave from the Midwest to East Coast; Severe Thunderstorms Across Portions of the Upper Midwest

A dangerous heat wave will persist through this weekend. Widespread warnings and advisories for the heat cover most of the eastern two-thirds of the U.S. Heat indices will surge past 100 degrees and even rise above 110 in many locations. Northwest of this dome of heat, severe thunderstorms with the possibility of strong tornadoes and widespread significant wind damage are possible into tonight. Read More >

Current conditions at

Gaithersburg - Montgomery County Airport (KGAI)

Lat: 39.17°NLon: 77.17°WElev: 495ft.

A Few Clouds

33°C

92°F

Humidity 56%
Wind Speed W 11 km/h
Barometer 1013.7 mb (29.92 in)
Dewpoint 23°C (74°F)
Visibility 16 km
Heat Index39°C (102°F)
Last update 19 Jul 6:56 pm EDT
Extended Forecast for

Derwood MD

Excessive Heat Watch July 21, 11:00am until July 21, 09:00pm
Excessive Heat Warning July 20, 11:00am until July 20, 09:00pm
Excessive Heat Warning until July 19, 09:00pm
Click here for hazard details and duration
Excessive Heat Watch
Excessive Heat Warning
...
  •  
    Excessive Heat Warning until July 19, 09:00pm

    NOW until
    9:00pm Fri

    Excessive Heat Warning

  • Tonight

    Tonight: Partly cloudy, with a low around 26. West wind 5 to 10 km/h.

    Partly Cloudy

    Low: 26 °C

  • Saturday

    Saturday: Mostly sunny and hot, with a high near 37. Heat index values as high as 44. West wind 8 to 11 km/h.

    Hot

    High: 37 °C

  • Saturday
    Night

    Saturday Night: Partly cloudy, with a low around 26. West wind 3 to 8 km/h.

    Partly Cloudy

    Low: 26 °C

  • Sunday

    Sunday: A chance of showers and thunderstorms after 2pm.  Mostly sunny and hot, with a high near 37. Heat index values as high as 43. West wind 8 to 11 km/h.  Chance of precipitation is 30%.

    Mostly Sunny
    then Chance
    T-storms

    High: 37 °C

  • Sunday
    Night

    Sunday Night: A chance of showers and thunderstorms, mainly before 2am.  Mostly cloudy, with a low around 24. West wind 5 to 8 km/h.  Chance of precipitation is 40%.

    Chance
    T-storms

    Low: 24 °C

  • Monday

    Monday: Showers and thunderstorms likely, mainly after 8am.  Mostly cloudy, with a high near 32. Chance of precipitation is 70%.

    T-storms
    Likely

    High: 32 °C

  • Monday
    Night

    Monday Night: Showers likely and possibly a thunderstorm.  Cloudy, with a low around 20. Chance of precipitation is 70%.

    Showers
    Likely

    Low: 20 °C

  • Tuesday

    Tuesday: A chance of showers.  Mostly cloudy, with a high near 27. Chance of precipitation is 50%.

    Chance
    Showers

    High: 27 °C

Detailed Forecast

Tonight
Partly cloudy, with a low around 26. West wind 5 to 10 km/h.
Saturday
Mostly sunny and hot, with a high near 37. Heat index values as high as 44. West wind 8 to 11 km/h.
Saturday Night
Partly cloudy, with a low around 26. West wind 3 to 8 km/h.
Sunday
A chance of showers and thunderstorms after 2pm. Mostly sunny and hot, with a high near 37. Heat index values as high as 43. West wind 8 to 11 km/h. Chance of precipitation is 30%.
Sunday Night
A chance of showers and thunderstorms, mainly before 2am. Mostly cloudy, with a low around 24. West wind 5 to 8 km/h. Chance of precipitation is 40%.
Monday
Showers and thunderstorms likely, mainly after 8am. Mostly cloudy, with a high near 32. Chance of precipitation is 70%.
Monday Night
Showers likely and possibly a thunderstorm. Cloudy, with a low around 20. Chance of precipitation is 70%.
Tuesday
A chance of showers. Mostly cloudy, with a high near 27. Chance of precipitation is 50%.
Tuesday Night
Partly cloudy, with a low around 17.
Wednesday
Mostly sunny, with a high near 28.
Wednesday Night
Mostly clear, with a low around 17.
Thursday
Sunny, with a high near 29.
Thursday Night
Mostly clear, with a low around 19.
Friday
Mostly sunny, with a high near 31.
Click Map For Forecast
Point Forecast:
Derwood MD
 39.12°N 77.13°W (Elev. 106 m)
4:31 pm EDT Jul 19, 2019
7pm EDT Jul 19, 2019-6pm EDT Jul 26, 2019
 
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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