Grand Lake St. Marys SPB Weather Forecast

    • 53
    • 75

    Chance Thunderstorms

    • 61
    • 79

    Rain Showers Likely

    • 38
    • 70

    Rain Showers

    • 32
    • 51

    Partly Sunny

    • 42
    • 55

    Mostly Sunny

    • 53
    • 70

    Partly Sunny

Today 16 Apr Mercer

Mostly cloudy with a chance of Showers with a slight chance of Thunderstorms this Morning, then partly cloudy with a chance of Showers and Thunderstorms this afternoon. Highs in the mid 70s. Southwest Winds 10 to 15 Mph with Gusts up to 25 Mph. Chance of rain 50 percent.

Tonight 16 Apr Mercer

Mostly clear. Lows in the lower 50s. West Winds 10 to 15 Mph, becoming northwest around 5 Mph after midnight.

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  • Temperature Forecast NOAA

  • Temperature Real-Time

Grand Lake St. Marys SPB Temperature Statistics

April Temperature

Versailles Darke County Airport (23 miles)

  • Lowest 7 April, 2026

    28.4 °F

  • Average April

    55.5 °F

  • Highest 13 April, 2026

    80.6 °F

Climate (2021–Present)

Versailles Darke County Airport (23 miles)

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  • Average Low 2021–2026

    43.2 °F

  • Average 2021–2026

    52.4 °F

  • Average High 2021–2026

    61.6 °F
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