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

Dangerous Heat and Heavy Rainfall into the Weekend

Hot temperatures and high humidity are forecast to continue across the mid-Mississippi Valley into this weekend. Heat Advisories remain in effect. Heavy to excessive rainfall occurring at times through the weekend could bring areas of flooding to parts of the northern Rockies, upper Midwest, central Great Lakes, and southern New England. Read More >

Hazardous Weather Conditions

Current conditions at

Pittsburgh - Allegheny County Airport (KAGC)

Lat: 40.36°NLon: 79.92°WElev: 1237ft.

Overcast

71°F

22°C

Humidity 94%
Wind Speed W 10 mph
Barometer 29.96 in (1014.1 mb)
Dewpoint 69°F (21°C)
Visibility 10.00 mi
Last update 20 Sep 1:53 pm EDT
Extended Forecast for

Cheswick PA

Flood Watch until September 21, 12:00pm
Click here for hazard details and duration
Flood Watch
  •  
    Flood Watch until September 21, 12:00pm

    NOW until 12:00pm Mon

    Flood Watch

  • This Afternoon

    High: 75 °F

    Showers
    Likely and
    Patchy Fog

  • Tonight

    Tonight: A chance of showers and thunderstorms. Patchy fog after 7pm. Otherwise, mostly cloudy, with a low around 56. Northeast wind 6 to 8 mph. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    Low: 56 °F

    Chance
    Showers and
    Patchy Fog

  • Monday

    Monday: Showers and possibly a thunderstorm before 1pm, then a chance of showers and thunderstorms between 1pm and 2pm, then showers likely and possibly a thunderstorm after 2pm. Patchy fog between 7am and 11am. High near 66. East wind 11 to 14 mph. Chance of precipitation is 90%. New rainfall amounts between a quarter and half of an inch possible.

    High: 66 °F

    Showers and
    Patchy Fog
    then Showers
    Likely

  • Monday Night

    Monday Night: Showers and thunderstorms. Low around 54. East wind 10 to 14 mph, with gusts as high as 24 mph. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.

    Low: 54 °F

    Showers

  • Tuesday

    Tuesday: Showers. High near 66. East wind 11 to 15 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.

    High: 66 °F

    Showers

  • Tuesday Night

    Tuesday Night: Showers likely. Cloudy, with a low around 52. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch possible.

    Low: 52 °F

    Showers
    Likely

  • Wednesday

    Wednesday: Showers likely, mainly before 2pm. Mostly cloudy, with a high near 64. Chance of precipitation is 60%.

    High: 64 °F

    Showers
    Likely

  • Wednesday Night

    Wednesday Night: A chance of showers. Mostly cloudy, with a low around 50. Chance of precipitation is 40%.

    Low: 50 °F

    Chance
    Showers

Detailed Forecast

This Afternoon
Showers likely and possibly a thunderstorm before 5pm, then a chance of showers and thunderstorms after 5pm. Patchy fog. Otherwise, mostly cloudy, with a high near 75. Calm wind becoming northwest 5 to 8 mph. Chance of precipitation is 70%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Tonight
A chance of showers and thunderstorms. Patchy fog after 7pm. Otherwise, mostly cloudy, with a low around 56. Northeast wind 6 to 8 mph. Chance of precipitation is 30%. New precipitation amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Monday
Showers and possibly a thunderstorm before 1pm, then a chance of showers and thunderstorms between 1pm and 2pm, then showers likely and possibly a thunderstorm after 2pm. Patchy fog between 7am and 11am. High near 66. East wind 11 to 14 mph. Chance of precipitation is 90%. New rainfall amounts between a quarter and half of an inch possible.
Monday Night
Showers and thunderstorms. Low around 54. East wind 10 to 14 mph, with gusts as high as 24 mph. Chance of precipitation is 80%. New precipitation amounts between a quarter and half of an inch possible.
Tuesday
Showers. High near 66. East wind 11 to 15 mph. Chance of precipitation is 80%. New precipitation amounts between a tenth and quarter of an inch possible.
Tuesday Night
Showers likely. Cloudy, with a low around 52. Chance of precipitation is 70%. New precipitation amounts between a tenth and quarter of an inch possible.
Wednesday
Showers likely, mainly before 2pm. Mostly cloudy, with a high near 64. Chance of precipitation is 60%.
Wednesday Night
A chance of showers. Mostly cloudy, with a low around 50. Chance of precipitation is 40%.
Thursday
A chance of showers before 2pm. Partly sunny, with a high near 64. Chance of precipitation is 30%.
Thursday Night
Partly cloudy, with a low around 47.
Friday
Mostly sunny, with a high near 68.
Friday Night
Partly cloudy, with a low around 46.
Saturday
Mostly sunny, with a high near 72.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Cheswick PA
 40.55°N 79.79°W (Elev. 1066 ft)
Last Update:
2:22 pm EDT Sep 20, 2026
Forecast Valid:
2pm EDT Sep 20, 2026-6pm EDT Sep 26, 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