Two arms of the Japanese government publish a definition of Kyushu, and they do not match. The transport ministry’s regional bureau calls its patch the seven prefectures of Kyushu plus part of Yamaguchi Prefecture. The Japan Meteorological Agency names eight prefectures across its two Kyushu regions, and the eighth of them, Yamaguchi, is on Honshu. Neither definition reaches Okinawa, and the agency does not put all of Kagoshima inside Kyushu either.
The agency’s northern Kyushu takes in Yamaguchi, and its Chugoku leaves it out
The Meteorological Agency publishes a page of regional names with the prefectures each one covers. The entry is printed as northern Kyushu with the words “Yamaguchi Prefecture included” attached to the name itself, and it lists six prefectures: Yamaguchi, Fukuoka, Oita, Saga, Kumamoto and Nagasaki. Southern Kyushu is a separate entry covering Miyazaki and Kagoshima. Counting the two entries together gives eight prefectures, and Yamaguchi is not on the island.
The list also shows what the bracket displaces. The agency’s Chugoku region lists four prefectures: Tottori, Shimane, Okayama and Hiroshima. Yamaguchi is named as a member prefecture only in the northern Kyushu entries, and in no other regional entry on the glossary: neither the Chugoku entry nor the Sanyo and Sanin subdivisions listed beneath it take it in. The wider grouping the agency calls western Japan is built from Kinki, Chugoku, Shikoku, northern Kyushu with Yamaguchi included, and southern Kyushu. Its western Japan Sea side grouping is narrower, taking the Kinki Sea of Japan side, Sanin and northern Kyushu with Yamaguchi included, and a note attached to that entry adds that northern Kyushu is excluded from the snowfall element of the seasonal forecast, so the same region name carries a different membership depending on which forecast product is being issued.
| Region name as the agency prints it | What the entry lists |
|---|---|
| Northern Kyushu (Yamaguchi Prefecture included) | Yamaguchi, Fukuoka, Oita, Saga, Kumamoto, Nagasaki |
| Southern Kyushu | Miyazaki, Kagoshima (Satsuma, Osumi and the Tanegashima and Yakushima districts) |
| Amami | Amami City, Oshima County, Toshima Village |
| Okinawa | Okinawa |
| Chugoku | Tottori, Shimane, Okayama, Hiroshima |
The transport bureau says seven prefectures and part of Yamaguchi
The Kyushu District Transport Bureau, a regional arm of the Ministry of Land, Infrastructure, Transport and Tourism, describes itself on its own recruitment page as an organisation whose jurisdiction covers the seven prefectures of Kyushu and part of Yamaguchi Prefecture. That is a third arrangement rather than a second one. The Meteorological Agency takes the whole of Yamaguchi into its northern Kyushu; the transport bureau takes part of it. So both bodies reach across the Kanmon Strait, and neither of them stops at the coastline.
The two definitions differ in degree rather than in kind. The bureau’s page pairs the jurisdiction sentence with a catchphrase about creating vitality in Kyushu through transport and tourism, and with four remits at the head of an open-ended list: sustainable local public transport, securing safety in transport, regional development through tourism, and securing people and raising productivity. The number seven is the figure a national office reaches for when it has to name the prefectures on the island itself, and it still comes with Yamaguchi attached.
Amami belongs to Kagoshima, and the agency files it with Okinawa
The southern Kyushu entry does not take all of Kagoshima Prefecture. It names Miyazaki and then Kagoshima in three districts only: Satsuma, Osumi, and Tanegashima and Yakushima. The rest of the prefecture is a separate entry called Amami, which lists Amami City, Oshima County and Toshima Village. Higher up the same page, the agency’s broad groupings place Okinawa and Amami together in one heading, separate from western Japan. A reader who takes Kyushu to mean the whole of Kagoshima is looking at the wrong regional forecast for Amami and for Toshima Village.
Okinawa is its own entry, listing Okinawa Prefecture, and the agency subdivides it into Okinawa Main Island, the Daito Islands, Miyakojima, Ishigakijima and Yonaguni, with Yaeyama defined as Ishigakijima plus Yonaguni. What the prefecture publishes about the number of islands Okinawa counts is a separate matter from the forecast regions.
Typhoon approaches to the region are counted from 1951, and 89 of them fell in August
The agency keeps a separate statistics page headed with the same bracketed region name, northern Kyushu with Yamaguchi included, counting the typhoons that approached it. The table runs from 1951 to 2025, which is 75 rows, and its caption offers the same figures as a downloadable file. The recent years are low: 2 approaches in 2025, 2 in 2024 and 1 in 2023, against 5 in 2022, 3 in 2021, 3 in 2020, 5 in 2019 and 8 in 2018.
Adding the monthly columns down all 75 rows ourselves gives the shape of the season, and it is narrower than the calendar suggests. August accounts for 89 approaches and September for 69, with July on 55, June and October level on 21 each, May on 4, April on 2 and November on 1. The columns for January, February, March and December hold no entry at all in any of the 75 years. Counting the annual column the same way, the highest single year in the table is 2004 with 9 approaches, and two years, 1988 and 2001, carry no approach at all. Every figure in this paragraph is a count we made from the agency’s own table rather than a total the page prints.
January is the coldest month in Fukuoka and Kagoshima, and the wettest month is not the same
Both cities have a full set of 1991 to 2020 normals from 30 years of data, with no partial-period marks in the temperature, precipitation, snow or thunder columns, so the two can be read side by side.
| Normal, 1991 to 2020 | Fukuoka | Kagoshima |
|---|---|---|
| Coldest month by mean temperature | January, 6.9C | January, 8.7C |
| Mean daily minimum in that month | 3.9C | 4.9C |
| Warmest month by mean temperature | August, 28.4C | August, 28.8C |
| Annual mean temperature | 17.3C | 18.8C |
| Wettest month by precipitation | July, 299.1 mm | June, 570.0 mm |
| Annual precipitation | 1,686.9 mm | 2,434.7 mm |
| Days with snow per year | 23.4 | 10.0 |
| Days with thunder per year | 25.5 | 27.4 |
The single figure that separates the two is June. Kagoshima’s June normal of 570.0 mm is more than twice Fukuoka’s June normal of 249.6 mm, and it is the wettest month of the Kagoshima year by a margin of 204.9 mm over July, a subtraction we have made from the two printed normals. Fukuoka’s year peaks in July at 299.1 mm and never reaches 300 mm in any month. Subtracting the two annual totals gives Kagoshima 747.8 mm more rain in a normal year than Fukuoka, and both numbers come from the same 30-year period, so the difference is on one footing.
Snow is in the normals for both cities, and the deepest monthly normal is two centimetres
Fukuoka records 23.4 days with snow in a normal year, with 9.2 in January, 6.1 in December, 5.9 in February, 2.2 in March and 0.1 in November. Kagoshima records 10.0 days a year, with 4.3 in January. Those counts are days on which snow was observed, and they say nothing about depth. The depth columns are where the answer sits: the normal for the deepest snow depth in a month is 1 cm in Fukuoka in January and February and 2 cm in Kagoshima in January, and the annual figures in the same column are 2 cm for Fukuoka and 3 cm for Kagoshima.
The total depth of snowfall column behaves the same way: 1 cm in January and February for Fukuoka, 2 cm for the year, and 1 cm in each of January and December for Kagoshima, 2 cm for the year. Both tables also print dashes rather than zeros across the warmer months, and the ranges are not identical: Fukuoka’s three snow columns are dashed from April to November, while Kagoshima’s snowfall-total column is dashed from March to November and its deepest-depth column prints a zero for March.
Ten volcanoes sit at the end of the agency’s continuous-monitoring list
A press release dated 25 March 2026 states the shape of the monitoring programme in one sentence: of 111 active volcanoes, the agency had equipped 50 with seismometers, tiltmeters, infrasonic microphones, satellite positioning receivers and cameras and watched them around the clock. The same release announces that Nakanoshima, in Toshima Village in Kagoshima Prefecture, joined that group on 26 March 2026, taking the count from 50 to 51. Nakanoshima had been designated under the special measures law on active volcanoes, and the instruments were installed across two years starting in the 2024 financial year.
The page that maps the observation points lists all of the continuously monitored volcanoes in a single selector, and the final block of that list holds ten names: Tsurumidake and Garandake, Kujusan, Asosan, Unzendake, Kirishimayama, Sakurajima, Satsuma-Iwojima, Kuchinoerabujima, Nakanoshima and Suwanosejima. Counting every name in the selector ourselves gives 51, which matches the release. One of those ten, Nakanoshima, stands in Toshima Village, and Toshima Village is the municipality the agency’s own regional-names page files under Amami rather than under southern Kyushu. The newest addition to the list of volcanoes watched 24 hours a day is therefore in Kagoshima Prefecture and outside the agency’s Kyushu.
Sources Checked
Japan Meteorological Agency — glossary page of regional names and the prefectures each covers
Confirmed that northern Kyushu is printed with Yamaguchi Prefecture included and lists Yamaguchi, Fukuoka, Oita, Saga, Kumamoto and Nagasaki; that southern Kyushu lists Miyazaki and Kagoshima in the Satsuma, Osumi and Tanegashima and Yakushima districts; that Amami lists Amami City, Oshima County and Toshima Village; that Okinawa lists Okinawa Prefecture and is subdivided into Okinawa Main Island, the Daito Islands, Miyakojima, Ishigakijima and Yonaguni with Yaeyama as Ishigakijima plus Yonaguni; that Chugoku lists Tottori, Shimane, Okayama and Hiroshima; that western Japan is built from Kinki, Chugoku, Shikoku, northern Kyushu with Yamaguchi included and southern Kyushu; that the western Japan Sea side grouping is built from the Kinki Sea of Japan side, Sanin and northern Kyushu with Yamaguchi included; that Okinawa and Amami form a separate grouping; and the note attached to the western Japan Sea side entry that northern Kyushu is excluded from the snowfall element of the seasonal forecast.
https://www.jma.go.jp/jma/kishou/know/yougo_hp/tiikimei.html
Kyushu District Transport Bureau, Ministry of Land, Infrastructure, Transport and Tourism — page explaining what the bureau is
Confirmed that the bureau describes its jurisdiction as the seven prefectures of Kyushu and part of Yamaguchi Prefecture, that it is a regional arm of the ministry responsible for transport and tourism administration, and the stated remits of sustainable local public transport, transport safety, regional development through tourism, and workforce and productivity.
https://wwwtb.mlit.go.jp/kyushu/saiyou/00001_00575.html
Japan Meteorological Agency — statistics page counting typhoon approaches to northern Kyushu with Yamaguchi included
Confirmed that the page is headed with that bracketed region name, that the table runs from 1951 to 2025, that the caption describes the figures as typhoon approach counts up to 2025 and offers a downloadable file, and the annual figures of 2 for 2025, 2 for 2024, 1 for 2023, 5 for 2022, 3 for 2021, 3 for 2020, 5 for 2019 and 8 for 2018. The monthly totals of 89, 69, 55, 21, 21, 4, 2 and 1, the empty January, February, March and December columns, the 9 approaches in 2004 and the empty years 1988 and 2001 are counts we made from this table.
https://www.data.jma.go.jp/typhoon/statistics/accession/northern_kyushu.html
Japan Meteorological Agency — table of monthly and annual normals for Fukuoka
Confirmed the 1991 to 2020 statistical period and 30 years of data for every column used, the January mean of 6.9C and mean daily minimum of 3.9C, the August mean of 28.4C, the annual mean of 17.3C, the July precipitation normal of 299.1 mm, the June normal of 249.6 mm, the annual precipitation of 1,686.9 mm, the 23.4 snow days and 25.5 thunder days a year, the January, February and December snow-day figures of 9.2, 5.9 and 6.1, the deepest snow depth normals of 1 cm in January and February and 2 cm for the year, the snowfall depth totals of 1 cm in January and February and 2 cm for the year, and the dashes from April to November.
https://www.data.jma.go.jp/stats/etrn/view/nml_sfc_ym.php?prec_no=82&block_no=47807
Japan Meteorological Agency — table of monthly and annual normals for Kagoshima
Confirmed the 1991 to 2020 statistical period and 30 years of data for every column used, the January mean of 8.7C and mean daily minimum of 4.9C, the August mean of 28.8C, the annual mean of 18.8C, the June precipitation normal of 570.0 mm, the July normal of 365.1 mm, the annual precipitation of 2,434.7 mm, the 10.0 snow days and 27.4 thunder days a year, the January snow-day figure of 4.3, the deepest snow depth normals of 2 cm in January and 3 cm for the year, the snowfall depth totals of 1 cm in January and December and 2 cm for the year, and the dashes from March to November.
https://www.data.jma.go.jp/stats/etrn/view/nml_sfc_ym.php?prec_no=88&block_no=47827
Japan Meteorological Agency — press release of 25 March 2026 adding Nakanoshima to the continuously monitored volcanoes
Confirmed the 111 active volcanoes and 50 equipped for round-the-clock monitoring, the named instrument types, that Nakanoshima is in Toshima Village in Kagoshima Prefecture, that it was added on 26 March 2026, that the count moved from 50 to 51, the designation under the special measures law on active volcanoes, and the two-year installation programme from the 2024 financial year.
https://www.jma.go.jp/jma/press/2603/25b/20260325_nakanoshima.html
Japan Meteorological Agency — page mapping the observation points of the continuously monitored volcanoes
Confirmed the single selector listing every continuously monitored volcano, the final block of ten names from Tsurumidake and Garandake to Suwanosejima, and that counting all names in the selector gives 51.
https://www.jma.go.jp/jma/kishou/know/kazan/kansokumap/kansokumap.html
Last updated: September 2026
