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

Selinsgrove Penn Valley Airport (KSEG)

Lat: 40.82°NLon: 76.87°WElev: 443ft.

Mostly Cloudy

62°F

17°C

Humidity 96%
Wind Speed Calm
Barometer 30.19 in (1022.0 mb)
Dewpoint 61°F (16°C)
Visibility 10.00 mi
Last update 19 Aug 3:53 am EDT
Extended Forecast for

Northumberland PA

  • Overnight

    Overnight: Cloudy, with a low around 61. Calm wind.

    Low: 61 °F

    Cloudy

  • Tuesday

    Tuesday: Mostly cloudy, with a high near 76. Calm wind becoming southeast around 6 mph in the morning.

    High: 76 °F

    Mostly Cloudy

  • Tuesday Night

    Tuesday Night: A chance of showers, with thunderstorms also possible after 5am. Mostly cloudy, with a low around 62. Light southeast wind. Chance of precipitation is 30%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    Low: 62 °F

    Mostly Cloudy
    then Chance
    Showers

  • Wednesday

    Wednesday: A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 8am. Cloudy, with a high near 74. Southeast wind 3 to 5 mph. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    High: 74 °F

    Showers
    Likely

  • Wednesday Night

    Wednesday Night: A chance of showers and thunderstorms. Mostly cloudy, with a low around 62. Calm wind. Chance of precipitation is 50%. New precipitation amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    Low: 62 °F

    Chance
    Showers

  • Thursday

    Thursday: A slight chance of showers. Mostly cloudy, with a high near 76. Chance of precipitation is 20%.

    High: 76 °F

    Slight Chance
    Showers

  • Thursday Night

    Thursday Night: Partly cloudy, with a low around 57.

    Low: 57 °F

    Partly Cloudy

  • Friday

    Friday: Sunny, with a high near 83.

    High: 83 °F

    Sunny

  • Friday Night

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

    Low: 59 °F

    Mostly Clear

Detailed Forecast

Overnight
Cloudy, with a low around 61. Calm wind.
Tuesday
Mostly cloudy, with a high near 76. Calm wind becoming southeast around 6 mph in the morning.
Tuesday Night
A chance of showers, with thunderstorms also possible after 5am. Mostly cloudy, with a low around 62. Light southeast wind. Chance of precipitation is 30%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Wednesday
A chance of showers and thunderstorms, then showers likely and possibly a thunderstorm after 8am. Cloudy, with a high near 74. Southeast wind 3 to 5 mph. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Wednesday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 62. Calm wind. Chance of precipitation is 50%. New precipitation amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Thursday
A slight chance of showers. Mostly cloudy, with a high near 76. Chance of precipitation is 20%.
Thursday Night
Partly cloudy, with a low around 57.
Friday
Sunny, with a high near 83.
Friday Night
Mostly clear, with a low around 59.
Saturday
Mostly sunny, with a high near 83.
Saturday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 64. Chance of precipitation is 40%.
Sunday
A chance of showers. Partly sunny, with a high near 82. Chance of precipitation is 50%.
Sunday Night
A chance of showers. Partly cloudy, with a low around 58. Chance of precipitation is 30%.
Monday
Mostly sunny, with a high near 79.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Northumberland PA
 40.89°N 76.79°W (Elev. 482 ft)
Last Update:
3:35 am EDT Aug 19, 2025
Forecast Valid:
3am EDT Aug 19, 2025-6pm EDT Aug 25, 2025
 
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