Grassy Key Weather Forecast

    • 65
    • 73

    Mostly Sunny

    • 68
    • 75

    Mostly Sunny

    • 69
    • 76

    Mostly Sunny

    • 69
    • 76

    Mostly Sunny

    • 70
    • 76

    Mostly Sunny

    • 71
    • 77

    Mostly Sunny

Today 20 Mar Monroe Middle Keys

Mostly sunny. Breezy. Highs in the lower to mid 70s. Northeast Winds 15 to 20 Mph.

Tonight 20 Mar Monroe Middle Keys

Mostly clear. Lows in the mid 60s. North to northeast Winds 10 to 15 Mph.

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  • Temperature Real-Time

Grassy Key Temperature Statistics

March Temperature

The Florida Keys - Marathon International Airport (6.2 miles)

  • Lowest 18 March, 2026

    61 °F
  • Average March

    77.8 °F
  • Highest 16 March, 2026

    84.7 °F

Climate (2021–Present)

The Florida Keys - Marathon International Airport (6.2 miles)

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  • Average Low 2021–2026

    75.3 °F
  • Average 2021–2026

    80 °F
  • Average High 2021–2026

    85.1 °F
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