Grand Lake St. Marys SPB Weather Forecast

    • 40
    • 56

    Becoming Sunny

    • 44
    • 56

    Partly Sunny

    • 50
    • 63

    Rain Showers Likely

    • 55
    • 70

    Rain Showers Likely

    • 45
    • 66

    Rain Showers Likely

    • 44
    • 61

    Partly Sunny

Today 6 May Mercer

Partly cloudy. Unseasonably cold with Highs in the upper 50s. Northwest Winds 5 to 10 Mph.

Tonight 6 May Mercer

Partly cloudy in the Evening, then clearing. Unseasonably cold with Lows in the upper 30s. Northwest Winds around 5 Mph in the Evening, becoming light and variable.

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  • Temperature Forecast NOAA

  • Temperature Real-Time

Grand Lake St. Marys SPB Temperature Statistics

May Temperature

Versailles Darke County Airport (23 miles)

  • Lowest 2 May, 2026

    33.8 °F

  • Average May

    49.4 °F

  • Highest 4 May, 2026

    73.4 °F

Climate (2021–Present)

Versailles Darke County Airport (23 miles)

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  • Average Low 2021–2026

    43.2 °F

  • Average 2021–2026

    52.5 °F

  • Average High 2021–2026

    61.7 °F
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