The most detailed information about the water temperature in Port Jefferson in Atlantic Ocean (New York, United States). Forecast of changes in water temperature for the next 10 days. Statistics by months for recent years. Information about the neighboring resorts. Weather forecast in Port Jefferson for a week.
Water temperature in Port Jefferson right now
data updated 30 minutes ago45°F
yesterday: 45°F
a week ago: 42°F
Trend: slow rise
Today water temperature in Port Jefferson is 45.7°F. In general, this water temperature is unacceptable for swimming. But hardened people can afford to be in such water for 5-10 minutes. In any case, the general weather is also important. So, the air temperature at the same time will reach 50°F.
Analysis and forecast
The water temperature today roughly corresponds to the average value on this day in recent years. Its value has rise both over the past 20 days and over the past week. Exactly a year ago, on this day, the water temperature in this location was 46°F. Water temperature range in Port Jefferson in April is from 39 to 53 degrees.
According to our forecast, the water temperature in Port Jefferson will slowly rise for at least the next 10 days and reach a value of 47°F.
Table of water temperature values in Port Jefferson
| Day | Fact* | Average** | Forecast*** |
| Apr 9 | 6.5°C | 7.0°C | |
| Apr 10 | 6.7°C | 7.3°C | |
| Apr 11 | 6.9°C | 7.5°C | |
| Apr 12 | 6.8°C | 7.5°C | |
| Apr 13 | 6.8°C | 7.5°C | |
| Apr 14 | 7.6°C | 8.0°C | |
| Apr 15 | 7.7°C | 8.0°C | |
| Apr 16 | 7.6°C | 8.5°C | |
| Apr 17 | 8.8°C | 7.9°C | |
| Apr 18 | 8.8°C | 7.9°C | |
| Apr 19 | 8.8°C | 7.9°C | |
| Apr 20 | 8.8°C | 7.9°C | |
| Apr 21 | 9.3°C | 8.3°C | |
| Apr 22 | 9.0°C | 8.0°C | |
| Apr 23 | 9.0°C | 8.0°C |
** Average - Average water temperature on this day in past years
*** Forecast - Our forecast for the water temperature
Actual nearshore temperatures may vary by several degrees from the indicated values. This is noticeable after heavy rain or after prolonged periods of strong winds. Some downstream winds cause cold, deep waters to replace surface waters that have been warmed by the sun.
To develop a forecast, we use our own mathematical model, which takes into account the current change in water temperature, historical data and the main weather trends, wind strength and direction, air temperature in each specific region. We also take into account data for other resorts in United States.
Annual graph of average water temperature change in Port Jefferson
Water temperature in Port Jefferson by month
Port Jefferson located in the northern hemisphere, at latitude 40 degrees. The comfortable water temperature for swimming is set here in June, almost always only at the end of the month. During a year in Port Jefferson there are 89 days of swimming. In general, the swimming season ends in September. Average annual water temperature on the coast in Port Jefferson is 55°F, by the seasons: in winter 43°F, in spring 46°F, in summer 70°F, in autumn 62°F. Minimum water temperature (37°F) in Port Jefferson it happens in January, maximum (76°F) in July.
You can find out detailed data on how the water temperature in Port Jefferson changes in each specific month:
Port Jefferson: general information and map
Neighboring cities and resorts
| City | Water* | Distance** |
| East Setauket | 45°C | 3km |
| Mount Sinai | 45°C | 3km |
| Stony Brook | 45°C | 6km |
| Miller Place | 45°C | 6km |
| Nissequogue | 45°C | 12km |
| Long Island | 45°C | 18km |
| Northport | 46°C | 24km |
| West Sayville | 45°C | 24km |
| Bellport | 45°C | 24km |
| Fairfield | 46°C | 25km |
| Moriches | 46°C | 26km |
| Great River | 46°C | 26km |
** Straight line distance in kilometers
The warmest water today in United States recorded in Terra Mar, its value is 79°F. Lowest - in Nome, there water temperature now 27°F. Average water temperature in the country today - 55°F.
Water temperature data in Port Jefferson and neighboring towns and resorts collected from various sources, using buoys, using satellite maps of sea, river and lake surfaces of the NOAA agency.
We use data from various local authorities in each specific location of the world to more accurately reflect temperature values.
The nearest airport is located in a 16 kilometers. This is Long Island Mac Arthur (ISP) airport. We have no information as to whether it is valid and what flights it receives or sends.
Port Jefferson: weather forecast
The weather forecast is shown in local time in Port Jefferson
14km/hhumidity: 56%, clouds: 0%
14km/hhumidity: 41%, clouds: 0%
15km/hhumidity: 36%, clouds: 2%
17km/hhumidity: 35%, clouds: 3%
14km/hhumidity: 48%, clouds: 3%
10km/hhumidity: 53%, clouds: 36%
6km/hhumidity: 57%, clouds: 55%
9km/hhumidity: 69%, clouds: 39%
5km/hhumidity: 65%, clouds: 62%
7km/hhumidity: 57%, clouds: 71%
9km/hhumidity: 53%, clouds: 85%
12km/hhumidity: 62%, clouds: 100%
10km/hhumidity: 64%, clouds: 100%
12km/hhumidity: 78%, clouds: 100%
18km/hhumidity: 91%, clouds: 100%
25km/hhumidity: 91%, clouds: 100%
24km/hhumidity: 89%, clouds: 100%
25km/hhumidity: 80%, clouds: 100%
26km/hhumidity: 82%, clouds: 100%
21km/hhumidity: 85%, clouds: 100%
17km/hhumidity: 86%, clouds: 100%
14km/hhumidity: 86%, clouds: 100%
11km/hhumidity: 86%, clouds: 100%
9km/hhumidity: 85%, clouds: 100%
6km/hhumidity: 78%, clouds: 100%
9km/hhumidity: 66%, clouds: 100%
10km/hhumidity: 63%, clouds: 100%
11km/hhumidity: 67%, clouds: 100%
8km/hhumidity: 86%, clouds: 100%
7km/hhumidity: 90%, clouds: 100%
11km/hhumidity: 89%, clouds: 94%
12km/hhumidity: 93%, clouds: 100%
19km/hhumidity: 76%, clouds: 100%
20km/hhumidity: 42%, clouds: 79%
21km/hhumidity: 37%, clouds: 74%
24km/hhumidity: 37%, clouds: 48%
14km/hhumidity: 50%, clouds: 43%
