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

Dangerous Heat and Humidity Wednesday through Saturday

Dangerously hot and humid conditions are expected to build starting Wednesday through Saturday. Additionally, there will be a threat of thunderstorms on some of the days. View this briefing for details. Read More >

Hazardous Weather Conditions

Current conditions at

Chester County Airport (KMQS)

Lat: 39.98°NLon: 75.87°WElev: 659ft.

Overcast

73°F

23°C

Humidity 71%
Wind Speed Vrbl 3 mph
Barometer 30.06 in
Dewpoint 63°F (17°C)
Visibility 10.00 mi
Last update 1 Jul 1:15 am EDT
Extended Forecast for

2 Miles SE Downingtown PA

Extreme Heat Warning July 1, 12:00pm until July 4, 08:00pm
Click here for hazard details and duration
Extreme Heat Warning

  • Overnight

    Overnight: A slight chance of showers. Partly cloudy, with a low around 69. South wind around 5 mph. Chance of precipitation is 20%.

    Low: 69 °F

    Slight Chance
    Showers

  • Wednesday

    Wednesday: A slight chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 94. Heat index values as high as 102. Southwest wind 5 to 10 mph. Chance of precipitation is 20%.

    High: 94 °F

    Mostly Sunny
    then Slight
    Chance
    T-storms

  • Wednesday Night

    Wednesday Night: A slight chance of showers and thunderstorms before 11pm, then a slight chance of showers between 11pm and midnight. Partly cloudy, with a low around 74. Southwest wind 5 to 10 mph. Chance of precipitation is 20%.

    Low: 74 °F

    Slight Chance
    T-storms then
    Mostly Clear

  • Thursday

    Thursday: Sunny and hot, with a high near 98. Heat index values as high as 104. West wind 5 to 10 mph.

    High: 98 °F

    Hot

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 78. Southwest wind around 5 mph becoming calm after midnight.

    Low: 78 °F

    Mostly Clear

  • Friday

    Friday: Sunny and hot, with a high near 100.

    High: 100 °F

    Hot

  • Friday Night

    Friday Night: Mostly clear, with a low around 75.

    Low: 75 °F

    Mostly Clear

  • Independence Day

    Independence Day: A chance of showers and thunderstorms after 2pm. Mostly sunny and hot, with a high near 97. Chance of precipitation is 40%.

    High: 97 °F

    Sunny then
    Chance
    T-storms

  • Saturday Night

    Saturday Night: A chance of showers and thunderstorms before 2am. Mostly cloudy, with a low around 72. Chance of precipitation is 40%.

    Low: 72 °F

    Chance
    T-storms

Detailed Forecast

Overnight
A slight chance of showers. Partly cloudy, with a low around 69. South wind around 5 mph. Chance of precipitation is 20%.
Wednesday
A slight chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 94. Heat index values as high as 102. Southwest wind 5 to 10 mph. Chance of precipitation is 20%.
Wednesday Night
A slight chance of showers and thunderstorms before 11pm, then a slight chance of showers between 11pm and midnight. Partly cloudy, with a low around 74. Southwest wind 5 to 10 mph. Chance of precipitation is 20%.
Thursday
Sunny and hot, with a high near 98. Heat index values as high as 104. West wind 5 to 10 mph.
Thursday Night
Mostly clear, with a low around 78. Southwest wind around 5 mph becoming calm after midnight.
Friday
Sunny and hot, with a high near 100.
Friday Night
Mostly clear, with a low around 75.
Independence Day
A chance of showers and thunderstorms after 2pm. Mostly sunny and hot, with a high near 97. Chance of precipitation is 40%.
Saturday Night
A chance of showers and thunderstorms before 2am. Mostly cloudy, with a low around 72. Chance of precipitation is 40%.
Sunday
A chance of showers and thunderstorms after 2pm. Partly sunny, with a high near 91. Chance of precipitation is 50%.
Sunday Night
Showers and thunderstorms likely. Mostly cloudy, with a low around 69. Chance of precipitation is 60%.
Monday
A chance of showers and thunderstorms. Mostly cloudy, with a high near 84. Chance of precipitation is 50%.
Monday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 67. Chance of precipitation is 30%.
Tuesday
A chance of showers. Mostly sunny, with a high near 85. Chance of precipitation is 30%.
Basemap Options
Click map to change the forecast location
Loading map...
Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
2 Miles SE Downingtown PA
 39.99°N 75.67°W (Elev. 348 ft)
Last Update:
5:37 pm EDT Jun 30, 2026
Forecast Valid:
1am EDT Jul 1, 2026-6pm EDT Jul 7, 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