Grand Lake St. Marys SPB Weather Forecast

    • 46
    • 67

    Mostly Sunny

    • 48
    • 72

    Mostly Sunny

    • 43
    • 65

    Sunny

    • 48
    • 67

    Sunny

    • 51
    • 74

    Mostly Sunny

    • 50
    • 72

    Mostly Sunny

    • 50
    • 74

    Mostly Sunny

Today 3 Oct Mercer

Sunny. Highs in the upper 70s.

Tonight 3 Oct Mercer

Mostly clear. Patchy fog after midnight. Lows in the lower 40s. East Winds around 5 Mph until early Morning, becoming light and variable.

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  • Temperature Forecast NOAA

  • Temperature Real-Time

Grand Lake St. Marys SPB Temperature Statistics

October Temperature

Versailles Darke County Airport (23 miles)

  • Lowest 1 October, 2026

    62.6 °F

  • Average October

    74.3 °F

  • Highest 1 October, 2026

    86 °F

Climate (2021–2026)

Versailles Darke County Airport (23 miles)

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  • Average Low 2021–2026

    43.4 °F

  • Average 2021–2026

    52.6 °F

  • Average High 2021–2026

    61.8 °F
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