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 3.38°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.

38.1

°F

January 21, 10:06

Trend:

increasing

Yesterday:

38.0°F

Tomorrow:

38.4°F

Sunrise:

07:08

Sunset:

16:44

Day Length:

9 h. 36 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 38.1°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 1.7°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 rise a bit.

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 is also close to the historical minimum temperature for this date. The maximum temperature recorded for this date was 43.0°F on 2017, while the historical minimum was 36.8°F on 2025.

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. Over the next week, the forecast shows a steady trend, with temperatures staying close to the average of 38.2°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 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	41.0°F
Jan 12	37.7°F	38.8°F	40.9°F
Jan 13	36.8°F	38.5°F	40.7°F
Jan 14	37.4°F	38.5°F	40.8°F
Jan 15	37.8°F	37.6°F	40.6°F
Jan 16	38.6°F	36.5°F	40.4°F
Jan 17	36.9°F	37.1°F	40.3°F
Jan 18	37.3°F	37.5°F	40.0°F
Jan 19	37.5°F	37.8°F	40.0°F
Jan 20	38.0°F	38.2°F	40.0°F
Jan 21	38.1°F	36.8°F	39.8°F
Jan 22	38.4°F	37.4°F	40.1°F
Jan 23	38.4°F	37.0°F	40.1°F
Jan 24	38.6°F	37.5°F	40.4°F
Jan 25	38.4°F	37.6°F	40.1°F
Jan 26	38.1°F	37.1°F	39.9°F
Jan 27	37.8°F	37.3°F	39.6°F
Jan 28	37.7°F	37.1°F	39.4°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	38.1°F	2mi
Salem	40.1°F	14mi
Plymouth	37.0°F	34mi
Providence	36.7°F	41mi
Bristol	36.4°F	48mi

* current water temperature in this city

** straight line distance from Boston