Warmest sea in Japan in May

373 coastal locations in Japan ranked by their typical May sea temperature. Region-wide average in May: 17.4°C. The top of the list is where to find the warmest swimming this month.

Warmest in May

Yonakuni Shima

27.4°C May mean in Japan

Regional May average

17.4°C

across all 373 coastal locations in Japan

Vs annual mean

-1.7°C

below the year-round regional average

What the Japan sea feels like in May

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.

Japan monthly average 12.8°C to 26.6°C

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 May fits in the year

May 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 May mean, useful for trip planning weeks or months ahead.

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 warmest Japan locations in May

Sorted by the typical May mean built from a decade of daily readings at each location. Click any place for its 30-day chart, monthly profile, and full 10-year history.

#	Location	Country	May mean
1	Yonakuni Shima Okinawa	Japan	27.4°C
2	Yonakuni	Japan	27.3°C
3	Minami-Tori Shima Tokyo	Japan	27.0°C
4	Funauke Okinawa	Japan	26.9°C
5	Kobi Sho Okinawa	Japan	26.9°C
6	Ishigaki	Japan	26.8°C
7	lo Shima Tokyo	Japan	26.7°C
8	Hirara Okinawa	Japan	26.3°C
9	Miyakojima	Japan	26.3°C
10	Fuji	Japan	25.9°C
11	Kanegusuku Okinawa	Japan	25.5°C
12	Nakano Shima Kagoshima	Japan	25.4°C
13	Kerama Kaikyo (Zamami) Okinawa	Japan	25.0°C
14	Takara Shima Kagoshima	Japan	24.9°C
15	Naha Ko Okinawa	Japan	24.9°C
16	Tsuhako Okinawa	Japan	24.9°C
17	Haha Shima Tokyo	Japan	24.8°C
18	Minami-Daito Shima Okinawa	Japan	24.8°C
19	Haebaru	Japan	24.8°C
20	Itoman	Japan	24.8°C
21	Okinawa	Japan	24.8°C
22	Tomigusuku	Japan	24.8°C
23	Toguchi Okinawa	Japan	24.5°C
24	Chatan	Japan	24.5°C
25	Gushikawa	Japan	24.5°C

Show 25 more ▸

26	Suku Okinawa	Japan	24.5°C
27	Chichi Shima Tokyo	Japan	24.4°C
28	Kuchi-No-Erabu Shima Kagoshima	Japan	24.4°C
29	Nago	Japan	24.4°C
30	Gakiya Okinawa	Japan	24.3°C
31	Isso Kagoshima	Japan	24.0°C
32	Wadomari Kagoshima	Japan	23.9°C
33	Uken Kagoshima	Japan	23.9°C
34	Ogasawara	Japan	23.9°C
35	Kumano Kagoshima	Japan	23.9°C
36	Kasari Wan Kagoshima	Japan	23.9°C
37	Amami	Japan	23.8°C
38	Koniya Kagoshima	Japan	23.8°C
39	Sanmura Wan Kagoshima	Japan	23.7°C
40	Yakushima	Japan	23.1°C
41	Nishinoomote	Japan	22.3°C
42	Hachijo Jima Tokyo	Japan	22.1°C
43	Shibushi	Japan	21.9°C
44	Makurazaki	Japan	21.8°C
45	Tori Shima Tokyo	Japan	21.8°C
46	Aburatsu Miyazaki	Japan	21.8°C
47	Miyazaki Shi	Japan	21.7°C
48	Miyake Shima Tokyo	Japan	21.6°C
49	Tarumizu	Japan	21.6°C
50	Odomari Kagoshima	Japan	21.6°C

Coldest 10 in Japan in May

Same data the other way. Helpful if you want to know which Japan coasts to avoid for swimming in May.

#	Location	Country	May mean
1	Moyoro Wan Hokkaido	Japan	2.8°C
2	Shibetoro Hokkaido	Japan	2.8°C
3	Shana Wan Hokkaido	Japan	3.2°C
4	Hitokappi Wan Hokkaido	Japan	3.5°C
5	Naibo Wan Hokkaido	Japan	3.6°C
6	Furukamappu Wan Hokkaido	Japan	5.2°C
7	Kiritappu Hokkaido	Japan	6.0°C
8	Koiseboi Hokkaido	Japan	6.0°C
9	Hanasaki Hokkaido	Japan	6.2°C
10	Nemuro Ko Hokkaido	Japan	6.2°C