Marathon Weather Forecast

    • 80
    • 85

    Chance Rain Showers

    • 81
    • 86

    Chance Rain Showers

    • 81
    • 86

    Slight Chance Thunderstorms

    • 81
    • 86

    Slight Chance Thunderstorms

    • 81
    • 87

    Mostly Sunny

    • 82
    • 87

    Chance Thunderstorms

Today 19 May Monroe Middle Keys

Partly cloudy with a chance of Showers and a slight chance of Thunderstorms. Breezy. Highs in the upper 80s. East Winds 15 to 20 Mph. Chance of rain 40 percent.

Tonight 19 May Monroe Middle Keys

Partly cloudy with a chance of Showers and a slight chance of Thunderstorms. Breezy in the evening. Lows near 80. East Winds 15 to 20 Mph, decreasing to near 15 Mph. Chance of rain 40 percent.

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  • Temperature Forecast NOAA

  • Temperature Real-Time

Marathon Temperature Statistics

May Temperature

The Florida Keys - Marathon International Airport (2.5 miles)

  • Lowest 4 May, 2026

    72.6 °F

  • Average May

    81.8 °F

  • Highest 8 May, 2026

    87.7 °F

Climate (2021–Present)

The Florida Keys - Marathon International Airport (2.5 miles)

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  • Average Low 2021–2026

    75.3 °F

  • Average 2021–2026

    80 °F

  • Average High 2021–2026

    85 °F
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