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

April weather forecast and climate
Port Jefferson, NY

Ocean temperature

In Port Jefferson, New York, the average seawater temperature in April is 45.3°F (7.4°C).
Note: Swimming in 45.3°F (7.4°C) is considered dangerous. Unprotected immersion in temperatures below 50°F (10°C) causes quickly maximum intensity cold shock with hyperventilation.

Daylight

In Port Jefferson, the average length of the day in April is 13.3h.

What is the water temperature in April in Port Jefferson?

In Port Jefferson, in April, the average water temperature is 45.3°F (7.4°C). Swimming in 45.3°F (7.4°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 average length of the day in April in Port Jefferson?

In Port Jefferson, New York, the average length of the day in April is 13.3h.
Average sea temperature in April - Port Jefferson, NY
  • Average sea temperature in April: 45.4°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 April - Port Jefferson, NY
  • Average daylight in April: 13.3h

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