Merrian Weather Forecast

    • 63
    • 81

    Rain Showers Likely

    • 54
    • 75

    Becoming Sunny

    • 62
    • 78

    Chance Rain Showers

    • 65
    • 78

    Rain Showers

    • 56
    • 77

    Chance Thunderstorms

    • 57
    • 75

    Mostly Sunny

    • 60
    • 79

    Partly Sunny

Today 18 Jul Northumberland

Partly sunny with a chance of Showers and Thunderstorms. Some Thunderstorms may be severe with damaging Winds and frequent lightning. Highs in the mid 80s. Southwest Winds 5 to 10 Mph with Gusts up to 20 Mph. Chance of rain 50 percent.

Tonight 18 Jul Northumberland

Mostly cloudy. Showers likely with a chance of Thunderstorms this Evening, then a slight chance of Showers and Thunderstorms after midnight. Some Thunderstorms may be severe with damaging Winds and frequent lightning this evening. Lows in the mid 60s. Southwest Winds 5 to 10 Mph, becoming west after midnight. Chance of rain 70 percent.

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Merrian Temperature Statistics

July Temperature

Selinsgrove Penn Valley Airport (23.6 miles)

  • Lowest 13 July, 2026

    64 °F

  • Average July

    77.4 °F

  • Highest 1 July, 2026

    97 °F

Climate (2021–2026)

Selinsgrove Penn Valley Airport (23.6 miles)

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  • Average Low 2021–2026

    42.3 °F

  • Average 2021–2026

    52.7 °F

  • Average High 2021–2026

    63.1 °F
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