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Usu Wan Sea Temperature in September

Hokkaido, Japan

August Usu Wan year-round → October

Average sea temperature for Usu Wan, Japan across September, based on 10 years of daily readings.

Average

21.25° C

High

24.3° C

Low

18.62° 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 2nd warmest of 12 months at Usu Wan. On average the water sits 8.9° than the year-round mean of 12.33° C.

Compared to August, September is 1.1° cooler than (22.31° C in August). By October the water is usually 17.74° C.

Usu Wan Day-by-Day Water Temperature in September

10-year low, average and high

17.5° C
19.5° C
21.5° C
23.5° C
25.5° 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 Usu Wan.

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 Usu Wan

10-year daily averages

Day Average Low High
September 1 21.93° C 20.57° C 23.77° C
September 2 21.74° C 20.34° C 23.72° C
September 3 21.67° C 20.2° C 23.78° C
September 4 21.83° C 20.47° C 23.86° C
September 5 21.94° C 20.66° C 23.97° C
September 6 22.09° C 20.73° C 23.82° C
September 7 22.3° C 20.82° C 24.3° C
September 8 22.34° C 20.9° C 23.92° C
September 9 22.42° C 21.07° C 23.58° C
September 10 22.41° C 21.07° C 23.86° C
September 11 22.24° C 21° C 23.98° C
September 12 22.01° C 20.63° C 23.74° C
September 13 21.86° C 20.19° C 23.71° C
September 14 21.61° C 19.75° C 23.57° C
September 15 21.49° C 19.4° C 23.37° C
September 16 21.41° C 19.37° C 23.5° C
September 17 21.38° C 19.27° C 23.82° C
September 18 21.37° C 19.29° C 24.1° C
September 19 21.17° C 19.39° C 24.11° C
September 20 20.84° C 19.44° C 23.6° C
September 21 20.53° C 19.46° C 22.76° C
September 22 20.49° C 19.36° C 22.64° C
September 23 20.38° C 19.35° C 22.37° C
September 24 20.26° C 19.25° C 22.1° C
September 25 20.15° C 18.84° C 22.04° C
September 26 20.15° C 19.01° C 22.03° C
September 27 19.9° C 18.75° C 21.91° C
September 28 19.88° C 18.62° C 21.86° C
September 29 19.88° C 18.67° C 21.6° C
September 30 19.95° C 18.67° C 21.39° C

Where September Sits in the Year

September highlighted

-2.5° C
5.3° C
13.0° C
20.8° C
28.5° C
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
6.36° C
4.1° C
3.42° C
5.83° C
9.56° C
14.82° C
19.47° C
22.31° C
21.25° C
17.74° C
13.32° C
9.72° C
10-year monthly history for Usu Wan. 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 Japan water for the same month

Usu Wan Location

42.5167, 140.7670

42.51670, 140.76700 View on OpenStreetMap →

Usu Wan sits at 42.5167°N, 140.7670°E, on the coast of Hokkaido, Japan. 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 Usu Wan