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.

Fair

35°F

2°C

Humidity 100%
Wind Speed Calm
Barometer 30.52 in (1033.8 mb)
Dewpoint 35°F (2°C)
Visibility 10.00 mi
Last update 19 Oct 12:53 am EDT
Extended Forecast for

Northumberland PA

  • Overnight

    Overnight: Patchy fog after 2am. Widespread frost, mainly after 4am. Otherwise, clear, with a low around 29. Calm wind.

    Low: 29 °F

    Frost and
    Patchy Fog

  • Monday

    Monday: Patchy fog before 9am. Widespread frost before 9am. Otherwise, sunny, with a high near 67. Calm wind.

    High: 67 °F

    Frost and
    Patchy Fog
    then Sunny

  • Monday Night

    Monday Night: Clear, with a low around 37. Calm wind.

    Low: 37 °F

    Clear

  • Tuesday

    Tuesday: Patchy frost between 7am and 8am. Otherwise, sunny, with a high near 68. North wind 3 to 8 mph.

    High: 68 °F

    Patchy Frost
    then Sunny

  • Tuesday Night

    Tuesday Night: Patchy fog after 4am. Otherwise, mostly clear, with a low around 36. North wind around 6 mph becoming calm in the evening.

    Low: 36 °F

    Mostly Clear
    then Patchy
    Fog

  • Wednesday

    Wednesday: Patchy fog before 9am. Patchy frost before 9am. Otherwise, sunny, with a high near 65.

    High: 65 °F

    Patchy Frost
    and Patchy
    Fog then
    Sunny

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 35.

    Low: 35 °F

    Mostly Clear

  • Thursday

    Thursday: Patchy frost before 9am. Otherwise, sunny, with a high near 66.

    High: 66 °F

    Patchy Frost
    then Sunny

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 42.

    Low: 42 °F

    Mostly Clear

Detailed Forecast

Overnight
Patchy fog after 2am. Widespread frost, mainly after 4am. Otherwise, clear, with a low around 29. Calm wind.
Monday
Patchy fog before 9am. Widespread frost before 9am. Otherwise, sunny, with a high near 67. Calm wind.
Monday Night
Clear, with a low around 37. Calm wind.
Tuesday
Patchy frost between 7am and 8am. Otherwise, sunny, with a high near 68. North wind 3 to 8 mph.
Tuesday Night
Patchy fog after 4am. Otherwise, mostly clear, with a low around 36. North wind around 6 mph becoming calm in the evening.
Wednesday
Patchy fog before 9am. Patchy frost before 9am. Otherwise, sunny, with a high near 65.
Wednesday Night
Mostly clear, with a low around 35.
Thursday
Patchy frost before 9am. Otherwise, sunny, with a high near 66.
Thursday Night
Mostly clear, with a low around 42.
Friday
Sunny, with a high near 60.
Friday Night
Mostly clear, with a low around 36.
Saturday
Sunny, with a high near 60.
Saturday Night
Mostly clear, with a low around 36.
Sunday
Mostly sunny, with a high near 63.
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Forecast Area
Tiles ©ESRI

ABOUT THIS FORECAST

 
Point Forecast:
Northumberland PA
 40.89°N 76.79°W (Elev. 482 ft)
Last Update:
12:56 am EDT Oct 19, 2026
Forecast Valid:
1am EDT Oct 19, 2026-6pm EDT Oct 25, 2026
 
Forecast Discussion
 
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