Skip to content
seatemperatures.net

Coldest sea in Japan in September

373 coastal locations in Japan ranked by typical September sea temperature, coldest first. Region-wide average in September: 25.8°C.

Coldest in September

Moyoro Wan

13.8°C September mean in Japan

Regional September average

25.8°C

across all 373 coastal locations in Japan

Vs annual mean

+6.7°C

above the year-round regional average

What the Japan sea feels like in September

This water temperature is comparable to that of a swimming pool, but it might be higher than most open water swimmers prefer for serious swimming. Make sure to drink plenty of water before and after swimming and don't wear a wetsuit to avoid overheating.

Japan monthly average 12.8°C to 26.6°C
J
F
M
A
M
J
J
A
S
O
N
D
  • Warmest month August 26.6°C
  • Coldest month February 12.8°C
  • Annual mean 19.1°C
  • Months above 20°C 5 of 12

Where September fits in the year

September sits inside the regional pattern shown on the left. Pick a different month to see how the ranking shifts.

All twelve Japan month rankings:

Japan sea temperature map (live)

The map shows today's latest reading at every Japan location. The list below is based on the typical September mean.

Zoom in to see individual locations. Click a pin for water temperatures. View list →
°C -2 0 1 3 5 7 9 11 13 15 17 19 21 24 27 30 35

Top 50 coldest Japan locations in September

Sorted by typical September mean from a decade of daily readings, coldest first. Click any place for the full location page.

# Location September mean
1 Moyoro Wan Hokkaido 13.8°C
2 Hitokappi Wan Hokkaido 14.8°C
3 Mikuni 15.2°C
4 Muta 15.2°C
5 Shibetoro Hokkaido 15.3°C
6 Shana Wan Hokkaido 15.9°C
7 Naibo Wan Hokkaido 15.9°C
8 Hanasaki Hokkaido 17.4°C
9 Nemuro Ko Hokkaido 17.4°C
10 Kiritappu Hokkaido 17.6°C
11 Mombetsu 17.6°C
12 Hojo 17.7°C
13 Akkeshi Hokkaido 17.8°C
14 Kushiro 18.1°C
15 Furukamappu Wan Hokkaido 18.2°C
16 Shizunai 18.2°C
17 Hokkaido 18.2°C
18 Tomari Wan Hokkaido 18.4°C
19 Koiseboi Hokkaido 18.5°C
20 Abashiri Ko Hokkaido 18.7°C
21 Shibetsu 18.7°C
22 Rubeshibetsu Hokkaido 18.9°C
23 Soya Misaki Hokkaido 19.0°C
24 Monbetsu Hokkaido 19.1°C
25 Esashi (Hokkaido Ne Coast) Hokkaido 19.3°C
Show 25 more ▸
26 Omu Ko Hokkaido 19.4°C
27 Wakkanai 19.5°C
28 Tomakomai 20.4°C
29 Erimo Misaki Hokkaido 20.5°C
30 Sakai 20.6°C
31 Tenno 20.6°C
32 Oshidomari Wan Hokkaido 20.7°C
33 Noboribetsu 20.9°C
34 Urakawa Hokkaido 21.0°C
35 Hakodate 21.0°C
36 Muroran Hokkaidō 21.3°C
37 Usu Wan Hokkaido 21.3°C
38 Usujiri Hokkaido 21.3°C
39 Ishikari 21.3°C
40 Sapporo 21.3°C
41 Mori Ko Hokkaido 21.4°C
42 Tomamae Hokkaido 21.4°C
43 Otaru 21.4°C
44 Yoichi 21.4°C
45 Rumoi Hokkaido 21.5°C
46 Hachinohe 21.6°C
47 Miyako 21.7°C
48 Kamui Misaki Hokkaido 21.8°C
49 Kamaishi 22.1°C
50 Yamada 22.1°C

Warmest 10 in Japan in September

Same data the other way. The warmest spots for the same month.

# Location September mean
1 Minami-Tori Shima Tokyo 29.5°C
2 lo Shima Tokyo 29.4°C
3 Minami-Daito Shima Okinawa 29.3°C
4 Yonakuni Shima Okinawa 29.2°C
5 Fuji 29.2°C
6 Haha Shima Tokyo 29.2°C
7 Funauke Okinawa 29.1°C
8 Wadomari Kagoshima 29.1°C
9 Tsuhako Okinawa 29.1°C
10 Miyakojima 29.1°C

More on this region