Castle Island Weather Forecast

    • 66
    • 80

    Becoming Sunny

    • 62
    • 79

    Mostly Sunny

    • 65
    • 77

    Mostly Sunny

    • 65
    • 75

    Rain Showers Likely

    • 64
    • 78

    Chance Rain Showers

    • 65
    • 77

    Mostly Sunny

    • 68
    • 80

    Partly Sunny

Today 13 Aug Suffolk

Partly sunny with a 20 percent chance of Showers. Near steady temperature in the lower 80s. West Winds 5 to 10 Mph.

Tonight 13 Aug Suffolk

Partly cloudy. A slight chance of Showers in the evening. Lows in the mid 60s. Northwest Winds around 5 Mph. Chance of rain 20 percent.

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  • Temperature Forecast NOAA

  • Temperature Real-Time

Castle Island Temperature Statistics

August Temperature

Boston, Logan International Airport (1.2 miles)

  • Lowest 4 August, 2026

    66.7 °F

  • Average August

    79.9 °F

  • Highest 7 August, 2026

    94.6 °F

Climate (2021–2026)

Boston, Logan International Airport (1.2 miles)

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  • Average Low 2021–2026

    46.7 °F

  • Average 2021–2026

    53.7 °F

  • Average High 2021–2026

    61 °F
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