Isa is located in the northernmost inland area of Kagoshima Prefecture, about 75 kilometers north of the prefectural capital, Kagoshima City. The Kawauchi River runs through the city, which is surrounded by the Kyushu Mountains, and the urban center is part of the Oguchi Basin, with an elevation of about 180 meters.
Isa has a humid subtropical climate (Köppen climate classificationCfa) with hot summers and mild winters. Precipitation is significant throughout the year, and is heavier in summer, especially the months of June and July. The average annual temperature in Isa is 15.6 °C (60.1 °F). The average annual rainfall is 2,799.8 mm (110.23 in) with June as the wettest month. The temperatures are highest on average in August, at around 26.3 °C (79.3 °F), and lowest in January, at around 4.6 °C (40.3 °F).[2] The city recorded −15.2 °C (4.6 °F) on January 25, 2016 which is the lowest temperature ever recorded of Lowlands in Kyushu, while the extreme maximum temperature was 37.6 °C (99.7 °F) on August 18, 2020.[3]
Climate data for Ōkuchi, Isa (1991−2020 normals, extremes 1977−present)
Per Japanese census data, the population of Isa in 2020 is 24,453 people.[4] Isa's population peaked in the 1950s and has been steadily declining since then until 2020.
Historical population
Year
Pop.
±%
1920
37,437
—
1925
39,227
+4.8%
1930
42,281
+7.8%
1935
43,779
+3.5%
1940
44,880
+2.5%
1945
60,798
+35.5%
1950
61,082
+0.5%
1955
60,145
−1.5%
1960
56,404
−6.2%
1965
49,405
−12.4%
1970
42,905
−13.2%
Year
Pop.
±%
1975
39,343
−8.3%
1980
38,310
−2.6%
1985
37,483
−2.2%
1990
36,146
−3.6%
1995
35,007
−3.2%
2000
33,508
−4.3%
2005
31,499
−6.0%
2010
29,311
−6.9%
2015
26,810
−8.5%
2020
24,453
−8.8%
History
Isa is part of ancient Satsuma Province and was part of the holdings of Satsuma Domain in the Edo period. On April 1, 1889, the villages of Oguchi, Yamano, and Hazuki were established with the creation of the modern municipalities system. Oguchi was raised to town status in 1918, followed by Yamano in 1940. In 1954, Oguchi, Yamano, Hazuki, and Nishitara village in Isa District were merged to form the city of Oguchi. Likewise, the villages of Hishikari and Tara were established on April 1, 1889 with the creation of the modern municipalities system. In 1891, Tara was divided into Higashitara and Nishitara, and in 1925 Higashitara was renamed Honjo. In 1940, Hishikari was raised to town status, and in 1954, Hishikari annexed Honjo. The city of Isa was created on November 1, 2008, from the merger of the city of Ōkuchi, and the town of Hishikari (from Isa District). Isa District was dissolved as a result of this merger.[5]
Government
Isa has a mayor-council form of government with a directly elected mayor and a unicameral city council of 16 members. Isa contributes one member to the Kagoshima Prefectural Assembly. In terms of national politics, the city is part of the Kagoshima 3rd district of the lower house of the Diet of Japan.
Economy
The main economy activity of Isa is agriculture. Notable local products include rice, sweet potatoes and the production shōchū. The Hishikari mine is one of the few operational mines in Japan, and produces gold.
Education
Izumi has 13 public elementary schools, six public junior high schools and one public high school by the city government, and three public high schools operated by the Kagoshima Prefectural Board of Education. There is also one private high school (Izumi Chuo High School). The prefecture also operates a special education school for the handicapped.