Maine, USA
Long-term weather forecast
Long-term weather forecast

May weather forecast and climate
Belfast, ME

Ocean temperature

In Belfast, Maine, in Mayo, the average water temperature is 45.1°F (7.3°C).
Note: At temperatures below 50°F (10°C), swimming in a suitably protected swimsuit is feasible; otherwise, cold shock and loss of breathing control are imminent. Even a short swim, without thermal protection, at temperatures around 55.4°F (13°C) is not comfortable.


In Mayo, the average length of the day in Belfast is 14.8h.

How cold is the water in Mayo in Belfast?

In Mayo, the average ocean temperature in Belfast is 45.1°F (7.3°C). Swimming in 45.1°F (7.3°C) is considered life-threatening. Even a few minutes in 55.4°F (13°C) water is uncomfortable, and swimming below 50°F (10°C) may cause total loss of breathing control and cold shock, depending on a person's physique.

What is the average length of the day in Mayo in Belfast?

The average length of the day in Mayo is 14.8h.
Average sea temperature in May - Belfast, ME
  • Average sea temperature in May: 45.1°F

The best month for swimming (with the highest average sea temperature) is August (60.4°F).
The coldest month (with the lowest average sea temperature) is March (37.8°F).

Average daylight in May - Belfast, ME
  • Average daylight in May: 14.8h

The month with the longest days is June (Average daylight: 15.5h).
The month with shortest days is December (Average daylight: 8.9h).