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

Areas of Dangerous Heat and Heavy Rainfall Today

Hot temperatures and high humidity are forecast to continue across the mid-Mississippi Valley today. Heat Advisories remain in effect. Heavy to excessive rainfall today could bring areas of flooding to parts of the northern High Plains and Midwest into the Ohio Valley. Flood Watches remain in effect. Read More >

Current conditions at

Gaithersburg - Montgomery County Airport (KGAI)

Lat: 39.17°NLon: 77.17°WElev: 495ft.

Overcast

80°F

27°C

Humidity 74%
Wind Speed S 5 mph
Barometer 29.92 in (1014.1 mb)
Dewpoint 71°F (22°C)
Visibility 10.00 mi
Heat Index83°F (28°C)
Last update 20 Sep 4:56 pm EDT
Extended Forecast for

Olney MDSimilar City Names

  • This Afternoon

    This Afternoon: Isolated showers and thunderstorms. Mostly cloudy, with a high near 80. Southwest wind around 7 mph. Chance of precipitation is 20%.

    High: 80 °F

    Isolated
    T-storms

  • Tonight

    Tonight: Showers likely and possibly a thunderstorm before 8pm, then scattered showers between 8pm and 2am. Mostly cloudy, with a low around 62. Light and variable wind becoming north 5 to 7 mph in the evening. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    Low: 62 °F

    Showers
    Likely then
    Scattered
    Showers

  • Monday

    Monday: Scattered showers after 2pm. Mostly cloudy, with a high near 73. Northeast wind 8 to 11 mph. Chance of precipitation is 30%.

    High: 73 °F

    Partly Sunny
    then
    Scattered
    Showers

  • Monday Night

    Monday Night: Showers, mainly after 8pm. Low around 58. East wind around 9 mph. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.

    Low: 58 °F

    Showers

  • Tuesday

    Tuesday: Showers and possibly a thunderstorm. High near 64. Northeast wind 11 to 15 mph, with gusts as high as 20 mph. Chance of precipitation is 90%.

    High: 64 °F

    Showers

  • Tuesday Night

    Tuesday Night: Showers likely. Cloudy, with a low around 53. Chance of precipitation is 70%.

    Low: 53 °F

    Showers
    Likely

  • Wednesday

    Wednesday: A chance of showers. Mostly cloudy, with a high near 62. Chance of precipitation is 50%.

    High: 62 °F

    Chance
    Showers

  • Wednesday Night

    Wednesday Night: A chance of showers. Mostly cloudy, with a low around 52. Chance of precipitation is 40%.

    Low: 52 °F

    Chance
    Showers

  • Thursday

    Thursday: A chance of showers, mainly before 2pm. Mostly cloudy, with a high near 62. Chance of precipitation is 30%.

    High: 62 °F

    Chance
    Showers

Detailed Forecast

This Afternoon
Isolated showers and thunderstorms. Mostly cloudy, with a high near 80. Southwest wind around 7 mph. Chance of precipitation is 20%.
Tonight
Showers likely and possibly a thunderstorm before 8pm, then scattered showers between 8pm and 2am. Mostly cloudy, with a low around 62. Light and variable wind becoming north 5 to 7 mph in the evening. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Monday
Scattered showers after 2pm. Mostly cloudy, with a high near 73. Northeast wind 8 to 11 mph. Chance of precipitation is 30%.
Monday Night
Showers, mainly after 8pm. Low around 58. East wind around 9 mph. Chance of precipitation is 90%. New precipitation amounts between a quarter and half of an inch possible.
Tuesday
Showers and possibly a thunderstorm. High near 64. Northeast wind 11 to 15 mph, with gusts as high as 20 mph. Chance of precipitation is 90%.
Tuesday Night
Showers likely. Cloudy, with a low around 53. Chance of precipitation is 70%.
Wednesday
A chance of showers. Mostly cloudy, with a high near 62. Chance of precipitation is 50%.
Wednesday Night
A chance of showers. Mostly cloudy, with a low around 52. Chance of precipitation is 40%.
Thursday
A chance of showers, mainly before 2pm. Mostly cloudy, with a high near 62. Chance of precipitation is 30%.
Thursday Night
Mostly cloudy, with a low around 50.
Friday
Mostly sunny, with a high near 64.
Friday Night
Partly cloudy, with a low around 50.
Saturday
A slight chance of showers. Mostly sunny, with a high near 68. Chance of precipitation is 20%.
Saturday Night
Partly cloudy, with a low around 52.
Sunday
A slight chance of showers. Mostly sunny, with a high near 72.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Olney MDSimilar City Names
 39.14°N 77.1°W (Elev. 449 ft)
Last Update:
4:53 pm EDT Sep 20, 2026
Forecast Valid:
5pm EDT Sep 20, 2026-6pm EDT Sep 27, 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