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South Boston in December

Find out everything about the water temperature in South Boston in December. Average, minimum and maximum recorded temperatures as well as daily temperature in December for the last two years. Compare the current month's sea temperature data with other months of the year.
Water temperature in December
Minimum:

37.9 °F

Average:

44.2 °F

Maximum:

50.1 °F

Sea water temperature in South Boston in December

In the city of South Boston, the month of December is too cold for swimming. The minimum recorded temperature during this month was 37.9°F on December 30, 2022, with an average temperature being 44.2°F and a maximum temperature reaching 50.1°F on December 1, 2016.

Swing in the water of such temperature might lead to potential hypothermia within just a few minutes. Throughout the month of December, the sea temperature gradually gets colder. Starting with an average temperature of 46.0°F at the beginning of the month, it steadily decreases to around 42.4°F by the end.
Date 10 years average 2025 2024
Dec 1 46.8°F 44.2°F 46.0°F
Dec 2 46.7°F 44.2°F 45.7°F
Dec 3 46.5°F 44.5°F 44.1°F
Dec 4 46.3°F 44.4°F 44.6°F
Dec 5 46.0°F 43.4°F 44.8°F
Dec 6 46.1°F 44.1°F 44.8°F
Dec 7 45.7°F 44.2°F 43.9°F
Dec 8 45.4°F 44.3°F 43.1°F
Dec 9 45.5°F 43.7°F 43.6°F
Dec 10 45.4°F 44.0°F 43.9°F
Dec 11 45.3°F 44.2°F 44.2°F
Dec 12 45.2°F 43.6°F 44.4°F
Dec 13 44.9°F 43.3°F 43.9°F
Dec 14 44.4°F 43.4°F 42.2°F
Dec 15 44.2°F 43.4°F 41.0°F
Dec 16 43.7°F 42.4°F 41.7°F
Dec 17 43.8°F 42.5°F 42.3°F
Dec 18 43.9°F 42.0°F 42.9°F
Dec 19 43.6°F 40.9°F 42.4°F
Dec 20 43.3°F 41.4°F 42.7°F
Dec 21 43.0°F 41.1°F 42.8°F
Dec 22 43.1°F 41.2°F 41.9°F
Dec 23 42.7°F 41.2°F 41.1°F
Dec 24 42.3°F 41.5°F 41.4°F
Dec 25 42.2°F 41.8°F 41.2°F
Dec 26 42.3°F 41.6°F 41.4°F
Dec 27 42.2°F 41.7°F 41.1°F
Dec 28 42.3°F 41.4°F 41.4°F
Dec 29 42.2°F 41.5°F 41.5°F
Dec 30 42.0°F 41.6°F 41.7°F
Dec 31 41.7°F 40.7°F 39.4°F

Sea water temperature in South Boston by month

In an average year, South Boston offers no days when the water temperature is warm enough to swim comfortably. The warmest water in South Boston was recorded on July 29, 2020, reaching a 75.0°F. While the coldest temperature occurred on February 11, 2025, dipping to 32.5°F. The average readings by season are 41.0°F in Winter, 45.4°F in Spring, 65.1°F in Summer, and 58.0°F in Autumn. December's average temperature is a slight drop from November's average of 50.6°F. In January, the temperature is expected to decrease further, potentially averaging around 40.7°F.

Popular neighboring cities and resorts

City Water temperature* Distance**
Boston 40.9°F 2mi
Salem 41.9°F 15mi
Plymouth 39.6°F 32mi
Providence 37.1°F 40mi
Bristol 36.4°F 47mi

* current water temperature in this city

** straight line distance from South Boston