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.

Partly Cloudy

84°F

29°C

Humidity 55%
Wind Speed S 9 mph
Barometer 29.91 in (1012.3 mb)
Dewpoint 66°F (19°C)
Visibility 10.00 mi
Heat Index86°F (30°C)
Last update 1 Aug 3:53 pm EDT
Extended Forecast for

Northumberland PA

  • Tonight

    Tonight: A slight chance of showers between 2am and 5am. Mostly cloudy, with a low around 69. Southeast wind 5 to 7 mph. Chance of precipitation is 20%.

    Low: 69 °F

    Mostly Cloudy
    then Slight
    Chance
    Showers

  • Sunday

    Sunday: A chance of showers, then showers likely and possibly a thunderstorm after 2pm. Some of the storms could produce heavy rainfall. Cloudy, with a high near 80. South wind 6 to 10 mph, with gusts as high as 21 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    High: 80 °F

    Slight Chance
    Showers then
    Heavy Rain

  • Sunday Night

    Sunday Night: Showers and thunderstorms before 1am, then showers likely and possibly a thunderstorm between 1am and 5am, then showers likely after 5am. Some of the storms could produce heavy rainfall. Low around 68. Light southeast wind. Chance of precipitation is 80%. New rainfall amounts between a quarter and half of an inch possible.

    Low: 68 °F

    Heavy Rain

  • Monday

    Monday: A chance of showers before 11am, then a chance of showers and thunderstorms between 11am and 2pm, then showers likely and possibly a thunderstorm after 2pm. Mostly cloudy, with a high near 81. Light and variable wind. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.

    High: 81 °F

    Showers
    Likely

  • Monday Night

    Monday Night: Showers likely and possibly a thunderstorm before 8pm, then a slight chance of showers between 8pm and 2am. Mostly cloudy, with a low around 64. Calm wind. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    Low: 64 °F

    Showers
    Likely then
    Slight Chance
    Showers

  • Tuesday

    Tuesday: A chance of showers and thunderstorms after 2pm. Partly sunny, with a high near 82. Chance of precipitation is 50%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    High: 82 °F

    Mostly Sunny
    then Chance
    Showers

  • Tuesday Night

    Tuesday Night: A chance of showers before 2am. Mostly cloudy, with a low around 67. Chance of precipitation is 40%.

    Low: 67 °F

    Chance
    Showers

  • Wednesday

    Wednesday: Showers likely and possibly a thunderstorm after 2pm. Partly sunny, with a high near 83. Chance of precipitation is 70%.

    High: 83 °F

    Partly Sunny
    then Showers
    Likely

  • Wednesday Night

    Wednesday Night: Showers likely and possibly a thunderstorm before 2am. Mostly cloudy, with a low around 67. Chance of precipitation is 60%.

    Low: 67 °F

    Showers
    Likely

Detailed Forecast

Tonight
A slight chance of showers between 2am and 5am. Mostly cloudy, with a low around 69. Southeast wind 5 to 7 mph. Chance of precipitation is 20%.
Sunday
A chance of showers, then showers likely and possibly a thunderstorm after 2pm. Some of the storms could produce heavy rainfall. Cloudy, with a high near 80. South wind 6 to 10 mph, with gusts as high as 21 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Sunday Night
Showers and thunderstorms before 1am, then showers likely and possibly a thunderstorm between 1am and 5am, then showers likely after 5am. Some of the storms could produce heavy rainfall. Low around 68. Light southeast wind. Chance of precipitation is 80%. New rainfall amounts between a quarter and half of an inch possible.
Monday
A chance of showers before 11am, then a chance of showers and thunderstorms between 11am and 2pm, then showers likely and possibly a thunderstorm after 2pm. Mostly cloudy, with a high near 81. Light and variable wind. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch, except higher amounts possible in thunderstorms.
Monday Night
Showers likely and possibly a thunderstorm before 8pm, then a slight chance of showers between 8pm and 2am. Mostly cloudy, with a low around 64. Calm wind. Chance of precipitation is 60%. New precipitation amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Tuesday
A chance of showers and thunderstorms after 2pm. Partly sunny, with a high near 82. Chance of precipitation is 50%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Tuesday Night
A chance of showers before 2am. Mostly cloudy, with a low around 67. Chance of precipitation is 40%.
Wednesday
Showers likely and possibly a thunderstorm after 2pm. Partly sunny, with a high near 83. Chance of precipitation is 70%.
Wednesday Night
Showers likely and possibly a thunderstorm before 2am. Mostly cloudy, with a low around 67. Chance of precipitation is 60%.
Thursday
A chance of showers and thunderstorms after 2pm. Mostly sunny, with a high near 84. Chance of precipitation is 40%.
Thursday Night
A chance of showers and thunderstorms. Partly cloudy, with a low around 68. Chance of precipitation is 30%.
Friday
A chance of showers and thunderstorms. Mostly sunny, with a high near 85. Chance of precipitation is 30%.
Friday Night
A chance of showers and thunderstorms. Partly cloudy, with a low around 67. Chance of precipitation is 30%.
Saturday
A chance of showers and thunderstorms. Mostly sunny, with a high near 85. Chance of precipitation is 30%.
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ABOUT THIS FORECAST

 
Point Forecast:
Northumberland PA
 40.89°N 76.82°W (Elev. 545 ft)
Last Update:
2:46 pm EDT Aug 1, 2026
Forecast Valid:
4pm EDT Aug 1, 2026-6pm EDT Aug 8, 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