Castine Water Temperature

(Today) 2025

11.7°C / 53°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 Bar Harbor, ME: 11.9°C / 53.4°F

Current weather

21°C / 70°F
(few clouds)
Partly cloudy
Wind
8 mph
Humidity
74%

The measurements for the water temperature in Castine, Maine 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 Castine water temperature derived from many years of historical sea surface temperature data.

Castine average maximum / minimum water temperatures
Maximum and minimum monthly sea temperatures in Castine
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Min °C 3 2.2 1.7 3.1 5 7.4 11.1 12.2 11.8 9.4 7.4 5
Max °C 6.4 4.5 4.4 5.9 8.7 12.9 16 16.4 14.8 13.2 10.4 8.7
Min °F 38.8 36.8 36.1 38.7 42.4 47.5 53.9 55.6 54.4 50.4 46.5 42.4
Max °F 42.2 39.1 38.8 41.5 46.1 53 58.8 59.8 57.4 54.2 49.5 46.1

The warmest water temperature is in August with an average around 57.7°F / 14.3°C. The coldest month is March with an average water temperature of 37.4°F / 3.0°C.

7 day tide forecast for Castine

MonTueWedThuFriSatSun
  • High 3:14am
    (3.26m)
  • Low 9:33am
    (0.01m)
  • High 3:51pm
    (3.03m)
  • Low 9:54pm
    (0.34m)
  • High 4:06am
    (3.09m)
  • Low 10:22am
    (0.16m)
  • High 4:41pm
    (2.98m)
  • Low 10:49pm
    (0.41m)
  • High 4:59am
    (2.93m)
  • Low 11:11am
    (0.31m)
  • High 5:30pm
    (2.95m)
  • Low 11:44pm
    (0.46m)
  • High 5:53am
    (2.79m)
  • Low 12:01pm
    (0.45m)
  • High 6:21pm
    (2.92m)
  • Low 12:39am
    (0.48m)
  • High 6:49am
    (2.68m)
  • Low 12:51pm
    (0.55m)
  • High 7:11pm
    (2.92m)
  • Low 1:34am
    (0.46m)
  • High 7:45am
    (2.61m)
  • Low 1:43pm
    (0.62m)
  • High 8:01pm
    (2.94m)
  • Low 2:28am
    (0.42m)
  • High 8:39am
    (2.6m)
  • Low 2:34pm
    (0.65m)
  • High 8:51pm
    (2.98m)
7 day tide times for Castine

*These tide times are estimates based on the nearest accurate location (Castine, Penobscot Bay, Maine) and may differ by up to half an hour depending on distance. Please note, the tide times given are not suitable for navigational purposes.