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 4.51°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.

40.1

°F

January 11, 08:25

Trend:

stable

Yesterday:

40.2°F

Tomorrow:

40.2°F

Sunrise:

07:13

Sunset:

16:32

Day Length:

9 h. 19 min.

Boston in January

Minimum:

40.0°F

Average:

42.1°F

Maximum:

46.1°F

Sea water temperature in Boston today

As of now, in Boston, the water temperature is 40.1°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 1.0°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 slightly lower than the average registered over the last two weeks, indicating a slight cooling trend. It also falls within the range of the average temperature recorded for this date, suggesting a consistent weather trend. The maximum temperature recorded for this date was 44.7°F on 2016, while the historical minimum was 38.4°F on 2025.

latest data

last year

Over the last two weeks, the water temperature has stayed slightly lower than historical averages for those days. Over the next week, the forecast shows a steady trend, with temperatures staying close to the average of 39.8°F. Both minimum and maximum temperatures expected to be close to the average, offering a week of stable water conditions.

Daily water temperature in Boston

Date	Current Year actual* / forecast**	last year	10 years average
Jan 1	40.3°F	40.0°F	42.1°F
Jan 2	40.3°F	40.4°F	42.1°F
Jan 3	40.5°F	40.5°F	41.9°F
Jan 4	40.7°F	39.6°F	42.0°F
Jan 5	40.9°F	39.9°F	42.0°F
Jan 6	40.6°F	38.9°F	41.7°F
Jan 7	40.6°F	39.3°F	41.5°F
Jan 8	40.6°F	39.4°F	41.3°F
Jan 9	40.2°F	39.4°F	41.1°F
Jan 10	40.2°F	39.4°F	41.1°F
Jan 11	40.1°F	38.4°F	41.1°F
Jan 12	40.2°F	38.8°F	41.2°F
Jan 13	40.2°F	38.5°F	41.1°F
Jan 14	40.1°F	38.5°F	41.1°F
Jan 15	39.9°F	37.6°F	40.9°F
Jan 16	39.6°F	36.5°F	40.6°F
Jan 17	39.6°F	37.1°F	40.6°F
Jan 18	39.3°F	37.5°F	40.3°F
Dec 28	41.4°F	41.4°F	42.3°F
Dec 29	41.5°F	41.5°F	42.2°F
Dec 30	41.6°F	41.7°F	42.0°F
Dec 31	40.7°F	39.4°F	41.7°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 40.9°F in Winter, 45.4°F in Spring, 65.1°F in Summer, and 58.0°F in Autumn.

Popular neighboring cities and resorts

City	Water temperature*	Distance**
South Boston	40.1°F	2mi
Salem	40.3°F	14mi
Plymouth	38.0°F	34mi
Providence	36.8°F	41mi
Bristol	36.3°F	48mi

* current water temperature in this city

** straight line distance from Boston