South Boston Water Temperature
(Today) 2025
The water will feel cool (fresh). Probably too cold for all but seasoned swimmers. We'd recommend a 4mm or 5mm wetsuit if you want to stay in the water.
*Live data from BOSTON 16 NM East of Boston, MA: 12.8°C / 55°F
Current weather
(scattered clouds)
The measurements for the water temperature in South Boston, Massachusetts are provided by the daily satellite readings provided by the NOAA. The temperatures given are the sea surface temperature (SST) which is most relevant to recreational users.
*Live data may vary from satellite readings for a number of reasons. These include local factors, depth of smapling and time of day.
Water temp by month
Monthly average max / min water temperatures
The graph below shows the range of monthly South Boston water temperature derived from many years of historical sea surface temperature data.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Min °C | 3 | 2 | 1.6 | 3.4 | 6 | 11.1 | 16.3 | 18.4 | 16.1 | 11.6 | 9.1 | 5.3 |
| Max °C | 6.8 | 4.9 | 4.8 | 7.7 | 11.2 | 17.1 | 20.6 | 21 | 19.7 | 17.7 | 12.8 | 10.4 |
| Min °F | 38.9 | 36.7 | 36.2 | 39.8 | 44.9 | 54.4 | 63 | 66.2 | 62.4 | 55.3 | 49.8 | 43.5 |
| Max °F | 42.7 | 39.6 | 39.4 | 44.1 | 50.1 | 60.4 | 67.3 | 68.8 | 66 | 61.4 | 53.5 | 48.6 |
The warmest water temperature is in August with an average around 67.5°F / 19.7°C. The coldest month is March with an average water temperature of 37.8°F / 3.2°C.
