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

Heat Wave and Severe Thunderstorms this Independence Day

A prolonged, dangerous heat wave will persist through the Independence Day weekend across the Ohio Valley, Midwest, and Mid-Atlantic. Numerous temperature records are expected. Clusters of severe thunderstorms will move across parts of the Allegheny Plateau into Mid Atlantic this Independence Day, with potential for widespread damaging winds. Additional severe thunderstorms in the Great Plains. Read More >

Hazardous Weather Conditions

Current conditions at

Harrisburg, Harrisburg International Airport (KMDT)

Lat: 40.19°NLon: 76.76°WElev: 312ft.

Mostly Cloudy

83°F

28°C

Humidity 53%
Wind Speed NW 8 mph
Barometer 29.97 in (1014.5 mb)
Dewpoint 64°F (18°C)
Visibility 10.00 mi
Heat Index84°F (29°C)
Last update 4 Jul 7:56 am EDT
Extended Forecast for

Hallam PA

Extreme Heat Warning July 4, 08:50am until July 4, 08:00pm
Click here for hazard details and duration
Extreme Heat Warning
  •  
    Extreme Heat Warning July 4, 08:50am until July 4, 08:00pm

    NOW until 8:00pm Sat

    Extreme Heat Warning

  • Independence Day

    High: 97 °F

    Mostly Sunny
    then Severe
    Thunderstorms

  • Tonight

    Tonight: A chance of showers and thunderstorms, mainly before midnight. Some of the storms could be severe. Mostly cloudy, with a low around 72. West wind around 6 mph becoming calm in the evening. Chance of precipitation is 50%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.

    Low: 72 °F

    Severe
    Thunderstorms
    then Slight
    Chance
    T-storms

  • Sunday

    Sunday: Showers and thunderstorms likely, mainly after 5pm. Some of the storms could produce heavy rainfall. Partly sunny, with a high near 88. Calm wind becoming east around 5 mph in the afternoon. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.

    High: 88 °F

    Mostly Sunny
    then Heavy
    Rain

  • Sunday Night

    Sunday Night: Showers and thunderstorms before 2am, then showers likely and possibly a thunderstorm between 2am and 5am, then showers likely after 5am. Some of the storms could produce heavy rainfall. Low around 68. East wind 5 to 7 mph. Chance of precipitation is 90%. New rainfall amounts between 1 and 2 inches possible.

    Low: 68 °F

    Heavy Rain

  • Monday

    Monday: Showers, with thunderstorms also possible after 11am. High near 80. East wind around 8 mph. Chance of precipitation is 80%. New rainfall amounts between a quarter and half of an inch possible.

    High: 80 °F

    Showers

  • Monday Night

    Monday Night: Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 66. Chance of precipitation is 70%. New rainfall amounts between a quarter and half of an inch possible.

    Low: 66 °F

    Showers
    Likely

  • Tuesday

    Tuesday: A chance of showers, with thunderstorms also possible after 2pm. Mostly cloudy, with a high near 80. Chance of precipitation is 40%.

    High: 80 °F

    Chance
    Showers then
    Chance
    T-storms

  • Tuesday Night

    Tuesday Night: A chance of showers and thunderstorms before 8pm, then a chance of showers between 8pm and 2am. Mostly cloudy, with a low around 66. Chance of precipitation is 40%.

    Low: 66 °F

    Chance
    T-storms then
    Chance
    Showers

Detailed Forecast

Independence Day
A slight chance of showers between 3pm and 5pm, then a chance of showers and thunderstorms after 5pm. Some of the storms could be severe. Mostly sunny and hot, with a high near 97. Heat index values as high as 105. West wind 5 to 9 mph. Chance of precipitation is 30%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Tonight
A chance of showers and thunderstorms, mainly before midnight. Some of the storms could be severe. Mostly cloudy, with a low around 72. West wind around 6 mph becoming calm in the evening. Chance of precipitation is 50%. New rainfall amounts of less than a tenth of an inch, except higher amounts possible in thunderstorms.
Sunday
Showers and thunderstorms likely, mainly after 5pm. Some of the storms could produce heavy rainfall. Partly sunny, with a high near 88. Calm wind becoming east around 5 mph in the afternoon. Chance of precipitation is 60%. New rainfall amounts between a quarter and half of an inch possible.
Sunday Night
Showers and thunderstorms before 2am, then showers likely and possibly a thunderstorm between 2am and 5am, then showers likely after 5am. Some of the storms could produce heavy rainfall. Low around 68. East wind 5 to 7 mph. Chance of precipitation is 90%. New rainfall amounts between 1 and 2 inches possible.
Monday
Showers, with thunderstorms also possible after 11am. High near 80. East wind around 8 mph. Chance of precipitation is 80%. New rainfall amounts between a quarter and half of an inch possible.
Monday Night
Showers likely and possibly a thunderstorm. Mostly cloudy, with a low around 66. Chance of precipitation is 70%. New rainfall amounts between a quarter and half of an inch possible.
Tuesday
A chance of showers, with thunderstorms also possible after 2pm. Mostly cloudy, with a high near 80. Chance of precipitation is 40%.
Tuesday Night
A chance of showers and thunderstorms before 8pm, then a chance of showers between 8pm and 2am. Mostly cloudy, with a low around 66. Chance of precipitation is 40%.
Wednesday
Partly sunny, with a high near 83.
Wednesday Night
Partly cloudy, with a low around 68.
Thursday
A chance of showers and thunderstorms. Partly sunny, with a high near 88. Chance of precipitation is 30%.
Thursday Night
A chance of showers and thunderstorms. Mostly cloudy, with a low around 71. Chance of precipitation is 30%.
Friday
A chance of showers and thunderstorms. Partly sunny, with a high near 89. Chance of precipitation is 50%.
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Forecast Area
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ABOUT THIS FORECAST

 
Point Forecast:
Hallam PA
 40.02°N 76.6°W (Elev. 522 ft)
Last Update:
8:06 am EDT Jul 4, 2026
Forecast Valid:
8am EDT Jul 4, 2026-6pm EDT Jul 10, 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