New Castle Water Temperature

(Today) 2024

14°C / 57.2°F

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 Seavey Island, ME: 11.9°C / 53.4°F

Current weather

4°C / 39°F
(clear sky)
Partly cloudy
Wind
6 mph
Humidity
77%

The measurements for the water temperature in New Castle, New Hampshire 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 New Castle water temperature derived from many years of historical sea surface temperature data.

New Castle average maximum / minimum water temperatures
Maximum and minimum monthly sea temperatures in New Castle
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Min °C 3.8 2.4 2.1 3.7 5.2 10.2 14.9 16.9 14.3 9.8 8.3 5.7
Max °C 6.7 5.2 5.1 7.8 11.8 16.4 19.7 20.4 18.9 16.7 11.5 9.6
Min °F 40 37.4 37 40.3 44 52.8 60.7 63.8 59.6 52.4 48.2 43.8
Max °F 42.9 40.2 40 44.4 50.6 59 65.5 67.3 64.2 59.3 51.4 47.7

The warmest water temperature is in August with an average around 65.5°F / 18.6°C. The coldest month is March with an average water temperature of 38.5°F / 3.6°C.