Dangerous Heat Builds and Expands; Critical Fire Weather for the Southwest; Severe Thunderstorms for Plains and Midwest

Dangerous to record breaking heat will build across the center of the nation and slowly build eastward this week. Wildfire conditions remain critical for the Southwest and portions of the Great Basin through Monday. For the northern Plains and upper Midwest, severe thunderstorms with the potential for large to very large hail and severe winds are the primary hazards. Read More >

Current conditions at

Selinsgrove Penn Valley Airport (KSEG)

Lat: 40.82°NLon: 76.87°WElev: 443ft.

Fog/Mist

64°F

18°C

Humidity 100%
Wind Speed Calm
Barometer 30.05 in (1017.2 mb)
Dewpoint 64°F (18°C)
Visibility 5.00 mi
Last update 29 Jun 1:53 am EDT
Extended Forecast for

Herndon PA

  • Overnight

    Overnight: Patchy fog.  Otherwise, partly cloudy, with a low around 63. Calm wind.

    Low: 63 °F

    Patchy Fog

  • Monday

    Monday: Patchy fog before 9am.  Otherwise, mostly sunny, with a high near 89. Calm wind.

    High: 89 °F

    Patchy Fog
    then Mostly
    Sunny

  • Monday Night

    Monday Night: Mostly clear, with a low around 66. Calm wind.

    Low: 66 °F

    Mostly Clear

  • Tuesday

    Tuesday: Sunny, with a high near 90. Calm wind becoming south 5 to 8 mph in the afternoon.

    High: 90 °F

    Sunny

  • Tuesday Night

    Tuesday Night: Mostly clear, with a low around 71. South wind around 5 mph becoming calm  in the evening.

    Low: 71 °F

    Mostly Clear

  • Wednesday

    Wednesday: Sunny and hot, with a high near 98.

    High: 98 °F

    Hot

  • Wednesday Night

    Wednesday Night: Mostly clear, with a low around 74.

    Low: 74 °F

    Mostly Clear

  • Thursday

    Thursday: Sunny and hot, with a high near 100.

    High: 100 °F

    Hot

  • Thursday Night

    Thursday Night: Mostly clear, with a low around 75.

    Low: 75 °F

    Mostly Clear

Detailed Forecast

Overnight
Patchy fog. Otherwise, partly cloudy, with a low around 63. Calm wind.
Monday
Patchy fog before 9am. Otherwise, mostly sunny, with a high near 89. Calm wind.
Monday Night
Mostly clear, with a low around 66. Calm wind.
Tuesday
Sunny, with a high near 90. Calm wind becoming south 5 to 8 mph in the afternoon.
Tuesday Night
Mostly clear, with a low around 71. South wind around 5 mph becoming calm in the evening.
Wednesday
Sunny and hot, with a high near 98.
Wednesday Night
Mostly clear, with a low around 74.
Thursday
Sunny and hot, with a high near 100.
Thursday Night
Mostly clear, with a low around 75.
Friday
Sunny and hot, with a high near 100.
Friday Night
A chance of showers and thunderstorms. Partly cloudy, with a low around 73. Chance of precipitation is 30%.
Independence Day
A chance of showers and thunderstorms. Mostly sunny and hot, with a high near 96. Chance of precipitation is 40%.
Saturday Night
A chance of showers and thunderstorms. Partly cloudy, with a low around 70. Chance of precipitation is 30%.
Sunday
A chance of showers and thunderstorms. Mostly sunny and hot, with a high near 93. Chance of precipitation is 40%.
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ABOUT THIS FORECAST

 
Point Forecast:
Herndon PA
 40.72°N 76.85°W (Elev. 397 ft)
2:06 am EDT Jun 29, 2026
2am EDT Jun 29, 2026-6pm EDT Jul 5, 2026
 
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Additional Resources

Radar & Satellite Image

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Hourly Weather Forecast

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