New Jersey, USA
Long-term weather forecast
Long-term weather forecast

January weather forecast and climate
Sewaren, NJ

Ocean temperature

In Sewaren, New Jersey, the average seawater temperature in January is 41.7°F (5.4°C).
Note: Swimming in 41.7°F (5.4°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.


The average length of the day in January is 9.7h.

How cold is the water in January in Sewaren?

In Sewaren, New Jersey, in January, the average water temperature is 41.7°F (5.4°C). 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.

What is the average length of the day in January in Sewaren?

The average length of the day in January is 9.7h.
Average sea temperature in January - Sewaren, NJ
  • Average sea temperature in January: 41.7°F

The best month for swimming (with the highest average sea temperature) is August (74.1°F).
The coldest month (with the lowest average sea temperature) is February (39.7°F).

Average daylight in January - Sewaren, NJ
  • Average daylight in January: 9.7h

The month with the longest days is June (Average daylight: 15h).
The month with shortest days is December (Average daylight: 9.3h).