Port Jefferson
New York, USA
Long-term weather forecast
Long-term weather forecast

December weather forecast and climate
Port Jefferson, NY

Ocean temperature

In Diciembre, the average ocean temperature in Port Jefferson, New York, is 48.9°F (9.4°C).
Note: Swimming in 48.9°F (9.4°C) is considered dangerous. Unprotected immersion in temperatures below 50°F (10°C) causes quickly maximum intensity cold shock with hyperventilation.

Daylight

Diciembre has the shortest days of the year in Port Jefferson, with an average of 9.3h of daylight.

What is the water temperature in Diciembre in Port Jefferson?

In Diciembre, the average ocean temperature is 48.9°F (9.4°C). Swimming in 48.9°F (9.4°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 month with the shortest days in Port Jefferson?

Diciembre has the shortest days of the year in Port Jefferson, New York, with an average of 9.3h of daylight.

What is the average length of the day in Diciembre in Port Jefferson?

In Port Jefferson, New York, the average length of the day in Diciembre is 9.3h.
Average sea temperature in December - Port Jefferson, NY
  • Average sea temperature in December: 49°F

The best month for swimming (with the highest average sea temperature) is August (74°F).
The coldest month (with the lowest average sea temperature) is February (39.7°F).

Average daylight in December - Port Jefferson, NY
  • Average daylight in December: 9.3h

The month with the longest days is June (Average daylight: 15.1h).
The month with shortest days is December (Average daylight: 9.3h).