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

Severe Weather and Heavy Rainfall in the Ohio Valley; Heat Continuing in the South and Southeast

Severe thunderstorms with damaging wind gusts will be possible from the mid-Mississippi Valley into parts of the Ohio Valley and central Appalachians tonight. Heavy rain associated with these storms may lead to considerable flash and urban flooding impacts across portions of the Ohio Valley. Mid-summer heat persists from the Central Plains to the Southeast. Read More >

Current conditions at

Chester County Airport (KMQS)

Lat: 39.98°NLon: 75.87°WElev: 659ft.

Overcast

72°F

22°C

Humidity 91%
Wind Speed NW 9 mph
Barometer 29.86 in
Dewpoint 69°F (21°C)
Visibility 10.00 mi
Last update 12 Aug 2:35 am EDT
Extended Forecast for

Downingtown PA

  • Overnight

    Overnight: A chance of showers and thunderstorms. Mostly cloudy, with a low around 68. Calm wind. Chance of precipitation is 50%. New rainfall amounts between a quarter and half of an inch possible.

    Low: 68 °F

    Chance
    Showers

  • Wednesday

    Wednesday: A chance of showers, mainly before noon. Mostly sunny, with a high near 84. Calm wind becoming northwest around 5 mph. Chance of precipitation is 30%. New precipitation amounts between a tenth and quarter of an inch possible.

    High: 84 °F

    Chance
    Showers

  • Wednesday Night

    Wednesday Night: A chance of showers after 1am. Partly cloudy, with a low around 67. West wind around 5 mph becoming calm. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.

    Low: 67 °F

    Mostly Clear
    then Chance
    Showers

  • Thursday

    Thursday: Sunny, with a high near 85. West wind around 5 mph.

    High: 85 °F

    Sunny

  • Thursday Night

    Thursday Night: A slight chance of showers before 2am. Mostly cloudy, with a low around 69. West wind around 5 mph becoming calm. Chance of precipitation is 20%.

    Low: 69 °F

    Slight Chance
    Showers

  • Friday

    Friday: Mostly sunny, with a high near 82.

    High: 82 °F

    Mostly Sunny

  • Friday Night

    Friday Night: Mostly clear, with a low around 59.

    Low: 59 °F

    Mostly Clear

  • Saturday

    Saturday: Sunny, with a high near 81.

    High: 81 °F

    Sunny

  • Saturday Night

    Saturday Night: Partly cloudy, with a low around 60.

    Low: 60 °F

    Partly Cloudy

Detailed Forecast

Overnight
A chance of showers and thunderstorms. Mostly cloudy, with a low around 68. Calm wind. Chance of precipitation is 50%. New rainfall amounts between a quarter and half of an inch possible.
Wednesday
A chance of showers, mainly before noon. Mostly sunny, with a high near 84. Calm wind becoming northwest around 5 mph. Chance of precipitation is 30%. New precipitation amounts between a tenth and quarter of an inch possible.
Wednesday Night
A chance of showers after 1am. Partly cloudy, with a low around 67. West wind around 5 mph becoming calm. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch possible.
Thursday
Sunny, with a high near 85. West wind around 5 mph.
Thursday Night
A slight chance of showers before 2am. Mostly cloudy, with a low around 69. West wind around 5 mph becoming calm. Chance of precipitation is 20%.
Friday
Mostly sunny, with a high near 82.
Friday Night
Mostly clear, with a low around 59.
Saturday
Sunny, with a high near 81.
Saturday Night
Partly cloudy, with a low around 60.
Sunday
A chance of showers after 2pm. Mostly sunny, with a high near 83. Chance of precipitation is 40%.
Sunday Night
Showers likely. Mostly cloudy, with a low around 66. Chance of precipitation is 60%.
Monday
A chance of showers. Partly sunny, with a high near 83. Chance of precipitation is 40%.
Monday Night
A chance of showers. Partly cloudy, with a low around 63. Chance of precipitation is 30%.
Tuesday
Sunny, with a high near 83.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Downingtown PA
 40°N 75.7°W (Elev. 299 ft)
Last Update:
4:09 pm EDT Aug 11, 2026
Forecast Valid:
2am EDT Aug 12, 2026-6pm EDT Aug 18, 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