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

Dangerous Heat and Possible Flooding

Dangerous heat will persist across the Southwest U.S. through Saturday with daytime highs of 110-115°F. Extreme Heat Warnings remain in effect. Dangerous heat will build across the southern Plains again beginning this weekend. Heavy to excessive rain over the Carolinas Friday may lead to isolated areas of flash flooding. Read More >

Current conditions at

Chester County Airport (KMQS)

Lat: 39.98°NLon: 75.87°WElev: 659ft.

A Few Clouds

81°F

27°C

Humidity 67%
Wind Speed N 7 mph
Barometer 30.04 in
Dewpoint 69°F (21°C)
Visibility 10.00 mi
Heat Index84°F (29°C)
Last update 28 Aug 4:55 pm EDT
Extended Forecast for

Downingtown PA

  • Tonight

    Tonight: Mostly cloudy, then gradually becoming clear, with a low around 58. North wind around 5 mph becoming calm.

    Low: 58 °F

    Decreasing
    Clouds

  • Saturday

    Saturday: Sunny, with a high near 80. North wind around 5 mph becoming calm.

    High: 80 °F

    Sunny

  • Saturday Night

    Saturday Night: Increasing clouds, with a low around 62. Calm wind.

    Low: 62 °F

    Increasing
    Clouds

  • Sunday

    Sunday: A chance of showers and thunderstorms after 2pm. Partly sunny, with a high near 84. Calm wind becoming southwest around 5 mph in the morning. Chance of precipitation is 30%.

    High: 84 °F

    Partly Sunny
    then Chance
    Showers

  • Sunday Night

    Sunday Night: A chance of showers and thunderstorms before 8pm. Partly cloudy, with a low around 69. South wind around 5 mph becoming calm. Chance of precipitation is 30%.

    Low: 69 °F

    Chance
    Showers then
    Mostly Cloudy

  • Monday

    Monday: Partly sunny, with a high near 86.

    High: 86 °F

    Partly Sunny

  • Monday Night

    Monday Night: Mostly cloudy, with a low around 69.

    Low: 69 °F

    Mostly Cloudy

  • Tuesday

    Tuesday: A chance of showers after 2pm. Partly sunny, with a high near 87. Chance of precipitation is 30%.

    High: 87 °F

    Partly Sunny
    then Chance
    Showers

  • Tuesday Night

    Tuesday Night: A chance of showers before 8pm. Partly cloudy, with a low around 71. Chance of precipitation is 30%.

    Low: 71 °F

    Chance
    Showers then
    Partly Cloudy

Detailed Forecast

Tonight
Mostly cloudy, then gradually becoming clear, with a low around 58. North wind around 5 mph becoming calm.
Saturday
Sunny, with a high near 80. North wind around 5 mph becoming calm.
Saturday Night
Increasing clouds, with a low around 62. Calm wind.
Sunday
A chance of showers and thunderstorms after 2pm. Partly sunny, with a high near 84. Calm wind becoming southwest around 5 mph in the morning. Chance of precipitation is 30%.
Sunday Night
A chance of showers and thunderstorms before 8pm. Partly cloudy, with a low around 69. South wind around 5 mph becoming calm. Chance of precipitation is 30%.
Monday
Partly sunny, with a high near 86.
Monday Night
Mostly cloudy, with a low around 69.
Tuesday
A chance of showers after 2pm. Partly sunny, with a high near 87. Chance of precipitation is 30%.
Tuesday Night
A chance of showers before 8pm. Partly cloudy, with a low around 71. Chance of precipitation is 30%.
Wednesday
A chance of showers after 2pm. Mostly sunny, with a high near 88. Chance of precipitation is 30%.
Wednesday Night
A chance of showers. Mostly cloudy, with a low around 70. Chance of precipitation is 40%.
Thursday
A chance of showers. Partly sunny, with a high near 86. Chance of precipitation is 30%.
Thursday Night
A chance of showers. Partly cloudy, with a low around 67. Chance of precipitation is 30%.
Friday
Mostly sunny, with a high near 83.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Downingtown PA
 40.02°N 75.7°W (Elev. 338 ft)
Last Update:
4:08 pm EDT Aug 28, 2026
Forecast Valid:
5pm EDT Aug 28, 2026-6pm EDT Sep 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