Castle Island Weather Forecast

    • 74
    • 86

    Slight Chance Thunderstorms

    • 73
    • 88

    Slight Chance Thunderstorms

    • 73
    • 85

    Rain Showers Likely

    • 71
    • 86

    Mostly Sunny

    • 72
    • 85

    Slight Chance Thunderstorms

    • 69
    • 84

    Chance Rain Showers

Today 6 Aug Suffolk

Partly sunny with a slight chance of Showers and Thunderstorms. Near steady temperature in the upper 80s. Southwest Winds 5 to 10 Mph. Chance of rain 20 percent. Heat index Values up to 101.

Tonight 6 Aug Suffolk

Mostly clear. Humid with Lows in the mid 70s. Southwest Winds 5 to 10 Mph.

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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

    66.9 °F

  • Average August

    77.2 °F

  • Highest 4 August, 2026

    87.1 °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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