What is the current water temperature in Boston?

Q: What is the current water temperature in Boston?

As of now, in Boston, the water temperature is 5.2°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.

United States > Boston

Water temperature in Boston

Detailed information about the current water temperature in 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.

41.4

°F

December 20, 20:41

Trend:

stable

Yesterday:

40.9°F

Tomorrow:

41.1°F

Sunrise:

07:09

Sunset:

16:14

Day Length:

9 h. 5 min.

Boston in December

Minimum:

38.8°F

Average:

41.1°F

Maximum:

43.8°F

Sea water temperature in Boston today

As of now, in Boston, the water temperature is 41.4°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 2.5°F lower than the average recorded on this particular day in recent years. Since yesterday, there was a slight increase in temperature. This indicates a warming trend over the past day. According to the forecast, we expect the temperature to fall a bit.

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 46.6°F on 2015, while the historical minimum was 41.3°F on 2022.

latest data

last year

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 40.7°F, the minimum temperature may reach 40.4°F, and the maximum might stay at 41.2°F.

Daily water temperature in Boston

Date	Current Year actual* / forecast**	last year	10 years average
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	44.2°F
Dec 18	42.0°F	42.9°F	44.3°F
Dec 19	40.9°F	42.4°F	44.0°F
Dec 20	41.4°F	42.7°F	43.8°F
Dec 21	41.1°F	42.8°F	43.6°F
Dec 22	41.2°F	41.9°F	43.6°F
Dec 23	40.8°F	41.1°F	43.3°F
Dec 24	40.4°F	41.4°F	42.9°F
Dec 25	40.4°F	41.2°F	42.8°F
Dec 26	40.5°F	41.4°F	42.9°F
Dec 27	40.4°F	41.1°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 Boston by month

In an average year, Boston offers no days when the water temperature is warm enough to swim comfortably.

The warmest water in 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**
South Boston	41.4°F	2mi
Salem	43.3°F	14mi
Plymouth	41.4°F	34mi
Providence	40.1°F	41mi
Bristol	39.0°F	48mi

* current water temperature in this city

** straight line distance from Boston