Average Ocean Temperatures for Maine & New Hampshire
Average ocean temperatures for Maine and New Hampshire are listed below for each month in degrees Fahrenheit and degrees Celsius.
During winter, the sea temperatures off northern New England are similar to those all along the coast as far south as Maryland.
But come spring and summer, the ocean off of Maine simply doesn't build up much heat. The Atlantic ocean all along the coast of Maine and New Hampshire is noticeably chillier in summer than at beaches farther south.
At the north end of the US Atlantic coast, the ocean at Eastport Maine usually reaches 52 °F (11 °C) in late summer. But just a little to the southeast, at Bar Harbor, next to Acadia National Park, the ocean gets several degrees warmer.
Actual ocean temperatures do of course vary from year to year depending upon the weather and the flow of ocean currents.
Maine's waters are too cold for most people to stay in for long. Only the hardiest of swimmers can spend much time in the ocean off northern New England without a wetsuit.
These coastal water temperatures are averages compiled by the US National Oceanographic Data Center of the National Oceanic and Atmospheric Administration.
Portsmouth NH | Portland ME | Bar Harbor ME | Eastport ME | |
---|---|---|---|---|
January | 40 | 34 | 38 | 40 |
February | 35 | 33 | 36 | 37 |
March | 37 | 37 | 38 | 38 |
April | 43 | 40 | 44 | 40 |
May | 50 | 49 | 49 | 44 |
June | 55 | 56 | 55 | 46 |
July | 60 | 61 | 59 | 51 |
August | 62 | 62 | 62 | 51 |
September | 59 | 59 | 58 | 52 |
October | 52 | 52 | 54 | 50 |
November | 48 | 47 | 52 | 45 |
December | 41 | 39 | 44 | 45 |
Annual | 48 | 47 | 49 | 45 |
Portsmouth NH | Portland ME | Bar Harbor ME | Eastport ME | |
---|---|---|---|---|
January | 4 | 1 | 3 | 4 |
February | 2 | 1 | 2 | 3 |
March | 3 | 3 | 3 | 3 |
April | 6 | 4 | 6 | 4 |
May | 10 | 9 | 9 | 6 |
June | 13 | 13 | 13 | 8 |
July | 16 | 16 | 15 | 10 |
August | 16 | 16 | 16 | 11 |
September | 15 | 15 | 14 | 11 |
October | 11 | 11 | 12 | 10 |
November | 9 | 8 | 11 | 7 |
December | 5 | 4 | 7 | 7 |
Annual | 9 | 8 | 9 | 7 |
Reference
National Oceanographic Data Center. NOAA. NODC Coastal Water Temperature Guide (CWTG).