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Mystic Island Sea Temperature in September

New Jersey, United States

August Mystic Island year-round → October

Average sea temperature for Mystic Island, United States across September, based on 10 years of daily readings.

Average

22.8° C

High

25.94° C

Low

19.17° C

Water at this temperature is very pleasant to swim in. If you tend to wear a wetsuit when swimming, you might consider removing it now to avoid the body overheating.

September is the 3rd warmest of 12 months at Mystic Island. On average the water sits 8.6° than the year-round mean of 14.19° C.

Compared to August, September is 1.3° cooler than (24.13° C in August). By October the water is usually 19.01° C.

Mystic Island Day-by-Day Water Temperature in September

10-year low, average and high

18.0° C
20.3° C
22.5° C
24.8° C
27.0° C
1
5
10
15
20
25
30
Day-by-day low and high band with the 10-year daily average through September. Range Average

Each vertical bar above is one day of September. The shaded band covers the range the water has reached on that day across the last 10 years — the lowest reading at the bottom, the highest at the top. The line running through the bars is the daily average over those 10 years, so you can see the typical shape of the month at Mystic Island.

A narrow band means the temperature on that day has stayed close to the average year on year. A taller band means it has swung more, often because of changeable weather around that time of year. Hovering a day pulls up its low, average, and high.

September Water Temperature Table for Mystic Island

10-year daily averages

Day Average Low High
September 1 23.93° C 22.53° C 25.22° C
September 2 23.79° C 22.31° C 24.92° C
September 3 23.67° C 22.21° C 24.95° C
September 4 23.65° C 22.18° C 25.12° C
September 5 23.67° C 22.35° C 25.65° C
September 6 23.66° C 22.31° C 25.62° C
September 7 23.69° C 22.37° C 25.81° C
September 8 23.67° C 22.34° C 25.9° C
September 9 23.58° C 22.27° C 25.83° C
September 10 23.36° C 21.98° C 25.88° C
September 11 23.23° C 21.73° C 25.94° C
September 12 23.24° C 21.74° C 25.89° C
September 13 23.08° C 22.16° C 25.41° C
September 14 23° C 22.16° C 24.79° C
September 15 23.06° C 22.21° C 24.18° C
September 16 22.97° C 22.11° C 23.68° C
September 17 22.76° C 21.8° C 23.43° C
September 18 22.7° C 21.92° C 23.42° C
September 19 22.6° C 21.87° C 23.52° C
September 20 22.41° C 21.79° C 23.16° C
September 21 22.32° C 21.68° C 23.35° C
September 22 22.24° C 21.11° C 23.51° C
September 23 22.16° C 21.04° C 23.47° C
September 24 22° C 20.7° C 23.3° C
September 25 21.87° C 20.37° C 23.04° C
September 26 21.77° C 20.13° C 22.95° C
September 27 21.74° C 19.82° C 22.83° C
September 28 21.61° C 19.84° C 22.8° C
September 29 21.45° C 19.64° C 22.98° C
September 30 21.16° C 19.17° C 22.77° C

Where September Sits in the Year

September highlighted

-3.5° C
4.9° C
13.3° C
21.6° C
30.0° C
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
5.19° C
4.3° C
5.84° C
9.41° C
13.92° C
19.64° C
23.79° C
24.13° C
22.8° C
19.01° C
13.78° C
8.52° C
10-year monthly history for Mystic Island. Bars span historical low to high; the line marks the monthly average. Range Average
January → February → March → April → May → June → July → August → September → October → November → December →

Nearby Locations in September

Compare other United States water for the same month

Mystic Island Location

39.5685, -74.3881

39.56848, -74.38807 View on OpenStreetMap →

Mystic Island sits at 39.5685°N, 74.3881°W, on the coast of New Jersey, United States. The marker on the map shows the spot the readings on this page come from. It usually sits a short distance from the town centre, out on the open water itself, so the numbers stay tied to the coast rather than a generic point inland.

Coastlines bend, headlands focus the water, and the temperature can run noticeably differently between two beaches that look close together on a map. Comparing nearby locations is a quick way to see how local geography is shaping the readings.

Nearest locations to Mystic Island