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

September weather forecast and climate
Port Jefferson, NY

Ocean temperature

In Port Jefferson, New York, in Septiembre, the average water temperature is 69.6°F (20.9°C).
Note: For most, swimming in 69.6°F (20.9°C) is not an enjoyable activity. Furthermore, controlling your breathing becomes progressively more difficult as the water temperature decreases from 69.8°F (21°C) to 59°F (15°C).

Daylight

The average length of the day in Septiembre in Port Jefferson is 12.4h.

What is the ocean temperature in Septiembre in Port Jefferson?

In Port Jefferson, the average seawater temperature in Septiembre is 69.6°F (20.9°C). For swimming, a surface water temperature of 69.6°F (20.9°C) is not enjoyable for the majority. It is not considered safe, as controlling breathing becomes progressively more difficult as water temperature decreases below 69.8°F (21°C).

How many hours of daylight does Port Jefferson have in Septiembre?

In Septiembre, the average length of the day is 12.4h.
Average sea temperature in September - Port Jefferson, NY
  • Average sea temperature in September: 69.6°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 September - Port Jefferson, NY
  • Average daylight in September: 12.4h

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