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Tomari Wan Sea Temperature in September

Hokkaido, Japan

August Tomari Wan year-round → October

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

Average

18.35° C

High

21.9° C

Low

15.53° C

At this temperature, water will feel cold compared to a swimming pool, but with a bit of experience and practice most people will find the water relatively comfortable to swim in.

September is the 2nd warmest of 12 months at Tomari Wan. On average the water sits 9.5° than the year-round mean of 8.81° C.

Compared to August, September is 0.3° cooler than (18.67° C in August). By October the water is usually 15.52° C.

Tomari Wan Day-by-Day Water Temperature in September

10-year low, average and high

14.5° C
16.6° C
18.8° C
20.9° C
23.0° 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 Tomari 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 Tomari Wan

10-year daily averages

Day Average Low High
September 1 18.8° C 16.75° C 21.9° C
September 2 18.72° C 17.06° C 21.64° C
September 3 18.69° C 16.85° C 21.48° C
September 4 18.67° C 16.92° C 21.44° C
September 5 18.63° C 17.29° C 21.09° C
September 6 18.84° C 17.81° C 20.87° C
September 7 18.99° C 18.01° C 20.48° C
September 8 19.02° C 18.04° C 19.99° C
September 9 19.12° C 17.95° C 20.25° C
September 10 19.31° C 17.98° C 21.03° C
September 11 19.1° C 17.93° C 20.9° C
September 12 18.97° C 17.73° C 20.74° C
September 13 18.76° C 17.31° C 20.39° C
September 14 18.64° C 17.18° C 20.35° C
September 15 18.55° C 17.37° C 20.43° C
September 16 18.6° C 17.5° C 20.45° C
September 17 18.47° C 17.22° C 20.42° C
September 18 18.4° C 16.73° C 20.67° C
September 19 18.22° C 16.47° C 20.4° C
September 20 18.02° C 16.32° C 20.02° C
September 21 17.87° C 16.06° C 19.41° C
September 22 17.89° C 16.54° C 19.33° C
September 23 17.89° C 16.93° C 19.14° C
September 24 17.75° C 16.65° C 18.89° C
September 25 17.62° C 16.44° C 18.63° C
September 26 17.51° C 16.24° C 18.55° C
September 27 17.41° C 15.75° C 18.46° C
September 28 17.39° C 15.66° C 18.28° C
September 29 17.38° C 15.53° C 18.25° C
September 30 17.37° C 15.68° C 18.08° C

Where September Sits in the Year

September highlighted

-5.0° C
2.9° C
10.8° C
18.6° C
26.5° C
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
1.46° C
-0.42° C
-0.11° C
3.21° C
6.88° C
10.77° C
15.48° C
18.67° C
18.35° C
15.52° C
10.66° C
5.19° C
10-year monthly history for Tomari 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

Tomari Wan Location

43.7333, 145.4500

43.73330, 145.45000 View on OpenStreetMap →

Tomari Wan sits at 43.7333°N, 145.4500°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 Tomari Wan