Castle Island Weather Forecast

    • 55
    • 63

    Rain Likely

    • 57
    • 61

    Rain

    • 57
    • 62

    Rain Showers

    • 58
    • 61

    Rain Showers Likely

    • 57
    • 63

    Partly Sunny

    • 60
    • 66

    Partly Sunny

Today 25 Sep Suffolk

Partly sunny in the Morning, then cloudy with a chance of rain in the afternoon. Breezy with Highs in the upper 60s. Northeast Winds 15 to 25 Mph with Gusts up to 45 Mph. Chance of rain 40 percent.

Tonight 25 Sep Suffolk

Cloudy. A chance of rain in the Evening, then rain likely after midnight. Very windy with Lows in the mid 50s. North Winds 25 to 35 Mph with Gusts up to 55 Mph. Chance of rain 60 percent.

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  • Temperature Real-Time

Castle Island Temperature Statistics

September Temperature

Boston, Logan International Airport (1.2 miles)

  • Lowest 22 September, 2026

    53.1 °F

  • Average September

    67.5 °F

  • Highest 10 September, 2026

    87.7 °F

Climate (2021–2026)

Boston, Logan International Airport (1.2 miles)

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  • Average Low 2021–2026

    46.6 °F

  • Average 2021–2026

    53.6 °F

  • Average High 2021–2026

    61 °F
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