All data are in degrees Fahrenheit

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Water temperature in South Boston

Detailed information about the current water temperature in South Boston. The trend over the last two weeks, daily averages, and precise forecast of the water temperature changes. Gain a deeper understanding of seasonal dynamics with monthly statistical analyses covering recent years.
Sea temperature in South Boston now

42.5

°F

December 17, 07:25

Trend:

increasing

Yesterday:

42.4°F

Tomorrow:

42.5°F

Sunrise:

07:08

Sunset:

16:13

Day Length:

9 h. 5 min.

South Boston in December

Minimum:

38.8°F

Average:

41.1°F

Maximum:

43.8°F

Sea water temperature in South Boston today

As of now, in South Boston, the water temperature is 42.5°F. Swimming in water of this temperature is considered as extremely cold, and there's a substantial risk of hypothermia if exposed for more than a brief duration. Today's reading is 1.9°F lower than the average recorded on this particular day in recent years. The sea temperature remains approximately unchanged from yesterday. According to the forecast, we expect the temperature to stay about the same.

Recent sea temperature and forecast

Today's water temperature is considerably lower than the average registered over the last two weeks, indicating a slight cooling trend. It is also close to the historical minimum temperature for this date. The maximum temperature recorded for this date was 48.1°F on 2015, while the historical minimum was 42.3°F on 2024.

Observations from the last two weeks indicate that the water temperature was in proximity to the lowest values recorded on those days in the past. The forecast for the upcoming week shows a gradual cooling trend. The average temperature is expected to be 41.8°F, the minimum temperature may reach 41.0°F, and the maximum might stay at 42.5°F.

Daily water temperature in South Boston

Date Current Year

actual* / forecast**

last year 10 years average
Dec 3 44.5°F 44.1°F 46.7°F
Dec 4 44.4°F 44.6°F 46.5°F
Dec 5 43.4°F 44.8°F 46.2°F
Dec 6 44.1°F 44.8°F 46.3°F
Dec 7 44.2°F 43.9°F 45.9°F
Dec 8 44.3°F 43.1°F 45.7°F
Dec 9 43.7°F 43.6°F 45.7°F
Dec 10 44.0°F 43.9°F 45.6°F
Dec 11 44.2°F 44.2°F 45.5°F
Dec 12 43.6°F 44.4°F 45.4°F
Dec 13 43.3°F 43.9°F 45.2°F
Dec 14 43.4°F 42.2°F 44.7°F
Dec 15 43.4°F 41.0°F 44.5°F
Dec 16 42.4°F 41.7°F 44.2°F
Dec 17 42.5°F 42.3°F 44.4°F
Dec 18 42.5°F 42.9°F 44.5°F
Dec 19 42.3°F 42.4°F 44.3°F
Dec 20 41.9°F 42.7°F 43.8°F
Dec 21 41.6°F 42.8°F 43.6°F
Dec 22 41.7°F 41.9°F 43.6°F
Dec 23 41.4°F 41.1°F 43.3°F
Dec 24 41.0°F 41.4°F 42.9°F

* actual - actual temperature values

** forecast - projected values for the next week

Real-time coastal temperatures could deviate by several degrees from the provided readings. These deviations often become evident following intense rainfall or strong winds.

Our forecasting methodology leverages a mathematical model, that uses current water and weather conditions, historical records, wind intensity and direction.

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 41.1°F in Winter, 45.1°F in Spring, 65.0°F in Summer, and 58.0°F in Autumn.

Popular neighboring cities and resorts

City Water temperature* Distance**
Boston 42.5°F 2mi
Salem 44.3°F 15mi
Plymouth 42.2°F 32mi
Providence 40.3°F 40mi
Bristol 39.4°F 47mi

* current water temperature in this city

** straight line distance from South Boston