Izunokuni (伊豆の国市, Izunokuni-shi) is a city located in Shizuoka Prefecture, Japan. As of 10 July 2019, the city had an estimated population of 48,579 in 21,257 households [1] and a population density of 506 persons per km2. The total area of the city is 94.62 square kilometres (36.53 sq mi).

Ohito onsen in Izunokuni
Ohito onsen in Izunokuni
Flag of Izunokuni
Official logo of Izunokuni
Location of Izunokuni in Shizuoka Prefecture
Location of Izunokuni in Shizuoka Prefecture
Izunokuni is located in Japan
Coordinates: 35°2′N 138°56′E / 35.033°N 138.933°E / 35.033; 138.933Coordinates: 35°2′N 138°56′E / 35.033°N 138.933°E / 35.033; 138.933
RegionChūbu (Tōkai)
 • MayorToshiko Ono
 • Total94.62 km2 (36.53 sq mi)
 (July 2019)
 • Total48,579
 • Density510/km2 (1,300/sq mi)
Time zoneUTC+9 (Japan Standard Time)
- TreeNageia nagi
- Flowerviola
Phone number055-948-1413
Address340-1 Nakaoka Izunokuni-shi, Shizuoka-ken 410-2292
WebsiteOfficial website
Izunokuni City Hall


Izunokuni is located on the northern "neck" of the Izu Peninsula in eastern Shizuoka Prefecture. The region is hilly, with numerous hot springs. The climate of the region is temperate maritime, with hot, humid summers and short, cool winters, with the warm Kuroshio Current offshore having a moderating effect.

Surrounding municipalitiesEdit


Per Japanese census data,[2] the population of Izunokuni has been relatively stable over the past 30 years.

Historical population
1960 33,049—    
1970 37,984+14.9%
1980 44,046+16.0%
1990 48,369+9.8%
2000 50,062+3.5%
2010 49,274−1.6%


The city has a climate characterized by characterized by hot and humid summers, and relatively mild winters (Köppen climate classification Cfa). The average annual temperature in Izunokuni is 16.0 °C. The average annual rainfall is 1981 mm with September as the wettest month. The temperatures are highest on average in August, at around 26.5 °C, and lowest in January, at around 6.2 °C.[3]


During the late Heian and Kamakura periods, the town of Nirayama within the current borders of Izunokuni was the home of the Later Hōjō clan, who dominated Japanese politics in the 12th century. A castle was established at Nirayama by Ise Moritoki in 1493. During the Edo period, most of Izu Province was tenryō territory under direct control of the Tokugawa shogunate, who ruled Izu and parts of eastern Suruga Province from a daikansho established at Nirayama. After the Meiji Restoration, the area became the short-lived Nirayama Prefecture, which was merged into the equally short-lived Ashigara Prefecture in 1871. From 1876, the area has been part of Shizuoka Prefecture. During the cadastral reform of 1886, the area was reorganized into several villages under Kimisawa District, which was with Tagata District in 1896. In 1934, the village of Izunagaoka was elevated to town status, followed by Ōhito in 1940, and Nirayama in 1962.

The city of Izunokuni was created on April 1, 2005 from the merger of the towns of Izunagaoka, Nirayama and Ōhito (all from Tagata District).


Izunokuni has a mayor-council form of government with a directly elected mayor and a unicameral city legislature of 17 members. The city contributes one member to the Shizuoka Prefectural Assembly.


The economy of Izunokuni is dominated by agriculture (strawberries and tomatoes) and by tourism related to the hot spring resort industry.


Izunokuni has six public elementary schools and three public junior high schools operated by the city government, and two public high schools operated by the Shizuoka Prefectural Board of Education. The prefecture also operates one special education school for the handicapped.




Local attractionsEdit

National Historic sitesEdit

Nirayama reverberatory furnace site

Sister City relationsEdit

Notable people from IzunokuniEdit

A view from top of Mount Jōyama in Izunokuni


  1. ^ Izunokuni City official statistics (in Japanese)
  2. ^ Izunokuni population statistics
  3. ^ Izunokuni climate data
  4. ^ [1] UNESCO World Heritage Convention home page

External linksEdit

  Media related to Izunokuni, Shizuoka at Wikimedia Commons

  • Izunokuni City official website (in Japanese)
  •   Geographic data related to Izunokuni at OpenStreetMap