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

Chester County Airport (KMQS)

Lat: 39.98°NLon: 75.87°WElev: 659ft.

76°F

24°C

Humidity 79%
Wind Speed NW 8 mph
Barometer 29.92 in
Dewpoint 69°F (21°C)
Visibility 10.00 mi
Heat Index77°F (25°C)
Last update 14 Oct 4:35 pm EDT
Extended Forecast for

Saint Peters PA

  • This Afternoon

    This Afternoon: A slight chance of showers and thunderstorms. Mostly cloudy, with a high near 79. West wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 20%.

    High: 79 °F

    Slight Chance
    T-storms

  • Tonight

    Tonight: Mostly cloudy, with a low around 52. Northwest wind 5 to 10 mph becoming north after midnight.

    Low: 52 °F

    Mostly Cloudy

  • Thursday

    Thursday: Mostly sunny, with a high near 64. North wind around 5 mph becoming east in the afternoon.

    High: 64 °F

    Mostly Sunny

  • Thursday Night

    Thursday Night: A chance of showers, then showers likely and possibly a thunderstorm after 2am. Increasing clouds, with a low around 54. Southeast wind around 5 mph. Chance of precipitation is 60%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    Low: 54 °F

    Slight Chance
    Showers then
    Showers
    Likely

  • Friday

    Friday: A chance of showers, then showers and possibly a thunderstorm after 5pm. High near 76. Southwest wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    High: 76 °F

    Chance
    Showers then
    Showers

  • Friday Night

    Friday Night: Showers and possibly a thunderstorm before 11pm, then showers likely. Low around 44. Breezy. Chance of precipitation is 80%. New precipitation amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    Low: 44 °F

    Showers and
    Breezy

  • Saturday

    Saturday: Mostly sunny, with a high near 52. Breezy.

    High: 52 °F

    Mostly Sunny
    and Breezy

  • Saturday Night

    Saturday Night: Areas of frost. Otherwise, mostly clear, with a low around 34.

    Low: 34 °F

    Areas Frost

  • Sunday

    Sunday: Areas of frost before 10am. Otherwise, sunny, with a high near 56.

    High: 56 °F

    Areas Frost
    then Sunny

Detailed Forecast

This Afternoon
A slight chance of showers and thunderstorms. Mostly cloudy, with a high near 79. West wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 20%.
Tonight
Mostly cloudy, with a low around 52. Northwest wind 5 to 10 mph becoming north after midnight.
Thursday
Mostly sunny, with a high near 64. North wind around 5 mph becoming east in the afternoon.
Thursday Night
A chance of showers, then showers likely and possibly a thunderstorm after 2am. Increasing clouds, with a low around 54. Southeast wind around 5 mph. Chance of precipitation is 60%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Friday
A chance of showers, then showers and possibly a thunderstorm after 5pm. High near 76. Southwest wind 10 to 15 mph, with gusts as high as 25 mph. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Friday Night
Showers and possibly a thunderstorm before 11pm, then showers likely. Low around 44. Breezy. Chance of precipitation is 80%. New precipitation amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Saturday
Mostly sunny, with a high near 52. Breezy.
Saturday Night
Areas of frost. Otherwise, mostly clear, with a low around 34.
Sunday
Areas of frost before 10am. Otherwise, sunny, with a high near 56.
Sunday Night
Mostly clear, with a low around 36.
Monday
Sunny, with a high near 61.
Monday Night
Partly cloudy, with a low around 41.
Tuesday
Mostly sunny, with a high near 64.
Tuesday Night
Partly cloudy, with a low around 43.
Wednesday
Sunny, with a high near 65.
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ABOUT THIS FORECAST

 
Point Forecast:
Saint Peters PA
 40.14°N 75.79°W (Elev. 600 ft)
Last Update:
4:11 pm EDT Oct 14, 2026
Forecast Valid:
4pm EDT Oct 14, 2026-6pm EDT Oct 21, 2026
 
Forecast Discussion
 
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Additional Resources

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Chance of Precipitation