Hokkaido北海道
Iwanai 岩内町
Data last updated:
Iwanai, Hokkaido, Japan has a population of 10,393 (2025 national census). IPSS projections estimate 9,111 by 2030 and 5,353 by 2050 (a decrease of about 54.0% from 2020), with the share of residents aged 65+ rising from 37.5% in 2020 to 52.7%.Sources: Japan Census (Statistics Bureau), IPSS Regional Population Projections (2023)
2025
(Census)
10,393
2030
(Projection)
9,111
▼ -21.8%
2040
(Projection)
7,084
▼ -39.2%
2050
(Projection)
5,353
▼ -54.0%
Change vs. 2020 census
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Data Sources
- Portal Site of Official Statistics of Japan (e-Stat)（https://www.e-stat.go.jp/）
- National Institute of Population and Social Security Research (IPSS), Regional Population Projections (2023 ed.)
* This service uses the e-Stat API but its content is not guaranteed by the Japanese government.
Iwanai Population Table (1980–2050)
Population by year: national census results (restated to current municipal boundaries) and IPSS (2023) projections based on the 2020 census.
| Year | Population | vs 2020 | Type |
|---|---|---|---|
| 1980 | 22,373 | ▲ +92.1% | Census |
| 1985 | 20,892 | ▲ +79.4% | Census |
| 1990 | 19,372 | ▲ +66.3% | Census |
| 1995 | 17,895 | ▲ +53.6% | Census |
| 2000 | 16,726 | ▲ +43.6% | Census |
| 2005 | 15,744 | ▲ +35.2% | Census |
| 2010 | 14,451 | ▲ +24.1% | Census |
| 2015 | 13,042 | ▲ +12.0% | Census |
| 2020 | 11,648 | — | Census |
| 2025 | 10,393 | ▼ -10.8% | Census |
| 2030 | 9,111 | ▼ -21.8% | Projection |
| 2035 | 8,058 | ▼ -30.8% | Projection |
| 2040 | 7,084 | ▼ -39.2% | Projection |
| 2045 | 6,182 | ▼ -46.9% | Projection |
| 2050 | 5,353 | ▼ -54.0% | Projection |
About Iwanai
Overview
Iwanai (岩内町) is a municipality in Hokkaido, Japan, with a population of 10,393 as of 2025.
Population Projection of Iwanai
According to projections by Japan's National Institute of Population and Social Security Research (IPSS), Iwanai's population is expected to reach 9,111 by 2030 (-21.8%), 7,084 by 2040 (-39.2%), and 5,353 by 2050 (-54.0%). The town is projected to lose more than half its population over 30 years.
Aging Rate of Iwanai
The aging rate (percentage of residents aged 65 and over) is 37.5% as of 2020 and is projected to rise to 52.7% by 2050. More than half of residents will be seniors, placing the town in the "marginal municipality" category.
National Comparison
Iwanai is experiencing one of the faster rates of population decline in Japan.
National and Prefectural Rank
- Population decline rate: Ranked #193 out of 1903 municipalities nationwide.
- Aging rate in 2050: Ranked #384 out of 1903 nationwide.
- Population size: Ranked #1331 out of 1917 nationwide.
- Related: National rankings / All municipalities in Hokkaido
Earnings in Hokkaido (北海道): Average salary in Hokkaido (北海道) by age, gender and company sizejpsalary / MHLW Basic Survey on Wage Structure