# Saiki, Ōita

Saiki (佐伯市, Saiki-shi) is a city located in Ōita Prefecture, Japan. As of 31 October 2023, the city had an estimated population of 65,870 in 32921 households, and a population density of 73 persons per km$^2$. The total area of the city is 903.11 km$^2$ (348.69 sq mi), making it the largest city by area in Kyushu.

## Geography

Saiki is located in southeastern Ōita Prefecture, approximately 60 kilometers southeast of the prefectural capital at Ōita City. The eastern part faces the Bungo Channel and is within the borders of the Nippō Kaigan Quasi-National Park. It is noted for its ria coastal areas. The inland area of the city is mountainous and within the borders of the Sobo-Katamuki Quasi-National Park. The city is built on the largest alluvial plain in the prefecture, created by the Bansho River, a first-class river that flows through the city.

### Neighboring municipalities

Miyazaki Prefecture
* Hinokage
* Nobeoka
Ōita Prefecture
* Bungo-Ōno
* Tsukumi

### Climate

Saiki has a humid subtropical climate (Köppen climate classification Cfa) with hot summers and cool winters. Precipitation is significant throughout the year, but is somewhat lower in winter. The average annual temperature in Saiki is 16.7 °C (62.1 °F). The average annual rainfall is 2,118.9 mm (83.42 in) with September as the wettest month. The temperatures are highest on average in August, at around 27.3 °C (81.1 °F), and lowest in January, at around 6.7 °C (44.1 °F). The highest temperature ever recorded in Saiki was 38.3 °C (100.9 °F) on 18 August 2020; the coldest temperature ever recorded was −10.5 °C (13.1 °F) on 11 February 1996.
Climate data for Saiki (1991−2020 normals, extremes 1977−present) :
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
| Record high °C (°F) | 21.5 (70.7) | 23.5 (74.3) | 27.0 (80.6) | 28.7 (83.7) | 31.9 (89.4) | 34.8 (94.6) | 36.1 (97.0) | 36.6 (97.9) | 35.2 (95.4) | 31.9 (89.4) | 28.6 (83.5) | 24.3 (75.7) | 36.6 (97.9) |
| Mean daily maximum °C (°F) | 11.0 (51.8) | 11.7 (53.1) | 14.9 (58.8) | 19.7 (67.5) | 23.7 (74.7) | 26.1 (79.0) | 30.1 (86.2) | 31.3 (88.3) | 27.9 (82.2) | 23.2 (73.8) | 18.2 (64.8) | 13.2 (55.8) | 20.9 (69.7) |
| Daily mean °C (°F) | 6.7 (44.1) | 7.5 (45.5) | 10.5 (50.9) | 15.1 (59.2) | 19.3 (66.7) | 22.4 (72.3) | 26.3 (79.3) | 27.3 (81.1) | 24.1 (75.4) | 19.1 (66.4) | 13.9 (57.0) | 8.7 (47.7) | 16.7 (62.1) |
| Mean daily minimum °C (°F) | 2.5 (36.5) | 3.2 (37.8) | 6.1 (43.0) | 10.4 (50.7) | 15.0 (59.0) | 19.2 (66.6) | 23.2 (73.8) | 24.0 (75.2) | 20.9 (69.6) | 15.3 (59.5) | 9.7 (49.5) | 4.5 (40.1) | 12.8 (55.1) |
| Record low °C (°F) | −5.0 (23.0) | −5.5 (22.1) | −3.5 (25.7) | 1.3 (34.3) | 5.1 (41.2) | 11.5 (52.7) | 15.6 (60.1) | 17.0 (62.6) | 13.0 (55.4) | 5.4 (41.7) | 0.7 (33.3) | −3.4 (25.9) | −5.5 (22.1) |
| Average precipitation mm (inches) | 62.3 (2.45) | 70.9 (2.79) | 116.2 (4.57) | 136.8 (5.39) | 178.8 (7.04) | 333.3 (13.12) | 282.7 (11.13) | 247.2 (9.73) | 338.6 (13.33) | 200.6 (7.90) | 104.1 (4.10) | 60.1 (2.37) | 2,118.9 (83.42) |
| Average precipitation days (≥ 1.0 mm) | 5.3 | 7.2 | 9.6 | 9.8 | 10.1 | 14.5 | 12.1 | 11.0 | 11.3 | 7.5 | 7.0 | 5.2 | 110.6 |
| Mean monthly sunshine hours | 156.0 | 149.6 | 170.5 | 186.8 | 191.9 | 134.4 | 191.4 | 207.9 | 159.3 | 170.0 | 152.3 | 156.1 | 2,026.2 |
| Source: Japan Meteorological Agency ||||||||||||||
Climate data for Ume, Saiki (1991−2020 normals, extremes 1977−present) :
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
| Record high °C (°F) | 21.7 (71.1) | 24.2 (75.6) | 28.4 (83.1) | 31.5 (88.7) | 34.0 (93.2) | 34.3 (93.7) | 37.3 (99.1) | 38.1 (100.6) | 34.6 (94.3) | 32.3 (90.1) | 28.0 (82.4) | 23.7 (74.7) | 38.1 (100.6) |
| Mean daily maximum °C (°F) | 10.4 (50.7) | 11.8 (53.2) | 15.2 (59.4) | 20.3 (68.5) | 24.5 (76.1) | 26.4 (79.5) | 30.7 (87.3) | 31.3 (88.3) | 27.6 (81.7) | 22.9 (73.2) | 17.7 (63.9) | 12.5 (54.5) | 20.9 (69.7) |
| Daily mean °C (°F) | 3.9 (39.0) | 5.0 (41.0) | 8.3 (46.9) | 13.2 (55.8) | 17.7 (63.9) | 21.2 (70.2) | 25.2 (77.4) | 25.6 (78.1) | 22.1 (71.8) | 16.5 (61.7) | 10.9 (51.6) | 5.6 (42.1) | 14.6 (58.3) |
| Mean daily minimum °C (°F) | −1.7 (28.9) | −0.9 (30.4) | 2.1 (35.8) | 6.6 (43.9) | 11.8 (53.2) | 17.2 (63.0) | 21.4 (70.5) | 21.9 (71.4) | 18.1 (64.6) | 11.5 (52.7) | 5.3 (41.5) | 0.0 (32.0) | 9.4 (49.0) |
| Record low °C (°F) | −10.5 (13.1) | −10.5 (13.1) | −8.9 (16.0) | −4.8 (23.4) | −1.0 (30.2) | 6.1 (43.0) | 11.5 (52.7) | 13.4 (56.1) | 4.2 (39.6) | −0.2 (31.6) | −4.4 (24.1) | −9.4 (15.1) | −10.5 (13.1) |
| Average precipitation mm (inches) | 55.4 (2.18) | 69.6 (2.74) | 121.9 (4.80) | 142.0 (5.59) | 186.7 (7.35) | 368.9 (14.52) | 327.2 (12.88) | 347.9 (13.70) | 420.1 (16.54) | 198.0 (7.80) | 85.6 (3.37) | 58.6 (2.31) | 2,404.6 (94.67) |
| Average precipitation days (≥ 1.0 mm) | 5.2 | 7.4 | 10.0 | 9.8 | 10.3 | 14.9 | 12.5 | 13.2 | 12.6 | 8.0 | 6.7 | 5.4 | 116 |
| Mean monthly sunshine hours | 162.1 | 153.0 | 170.1 | 182.0 | 177.2 | 106.8 | 158.3 | 172.2 | 128.8 | 159.1 | 148.2 | 159.0 | 1,873.4 |
| Source: Japan Meteorological Agency ||||||||||||||
Climate data for Kamae, Saiki (1991−2020 normals, extremes 1977−present) :
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
| Record high °C (°F) | 20.7 (69.3) | 22.1 (71.8) | 28.3 (82.9) | 27.9 (82.2) | 30.6 (87.1) | 32.9 (91.2) | 37.6 (99.7) | 38.3 (100.9) | 34.8 (94.6) | 30.6 (87.1) | 26.6 (79.9) | 22.4 (72.3) | 38.3 (100.9) |
| Mean daily maximum °C (°F) | 11.8 (53.2) | 12.8 (55.0) | 15.7 (60.3) | 20.1 (68.2) | 23.8 (74.8) | 25.8 (78.4) | 29.3 (84.7) | 30.9 (87.6) | 28.5 (83.3) | 24.1 (75.4) | 19.0 (66.2) | 14.0 (57.2) | 21.3 (70.4) |
| Daily mean °C (°F) | 7.9 (46.2) | 8.6 (47.5) | 11.6 (52.9) | 15.9 (60.6) | 19.7 (67.5) | 22.4 (72.3) | 25.8 (78.4) | 27.2 (81.0) | 24.8 (76.6) | 20.2 (68.4) | 15.1 (59.2) | 10.0 (50.0) | 17.4 (63.4) |
| Mean daily minimum °C (°F) | 4.3 (39.7) | 4.9 (40.8) | 7.6 (45.7) | 11.9 (53.4) | 16.0 (60.8) | 19.6 (67.3) | 23.2 (73.8) | 24.5 (76.1) | 21.9 (71.4) | 17.1 (62.8) | 11.7 (53.1) | 6.4 (43.5) | 14.1 (57.4) |
| Record low °C (°F) | −5.7 (21.7) | −4.7 (23.5) | −3.4 (25.9) | 2.0 (35.6) | 7.4 (45.3) | 11.8 (53.2) | 16.4 (61.5) | 17.9 (64.2) | 12.4 (54.3) | 5.5 (41.9) | 2.0 (35.6) | −2.5 (27.5) | −5.7 (21.7) |
| Average precipitation mm (inches) | 68.0 (2.68) | 75.4 (2.97) | 143.8 (5.66) | 187.5 (7.38) | 244.2 (9.61) | 398.6 (15.69) | 255.7 (10.07) | 230.9 (9.09) | 336.7 (13.26) | 190.0 (7.48) | 127.3 (5.01) | 74.5 (2.93) | 2,334.9 (91.93) |
| Average precipitation days (≥ 1.0 mm) | 5.4 | 6.6 | 9.5 | 9.5 | 10.2 | 15.1 | 11.7 | 11.1 | 11.7 | 7.6 | 6.5 | 5.1 | 110 |
| Mean monthly sunshine hours | 183.2 | 171.0 | 185.5 | 192.4 | 182.4 | 117.1 | 171.5 | 198.9 | 168.0 | 182.7 | 167.3 | 180.4 | 2,110.5 |
| Source: Japan Meteorological Agency ||||||||||||||

### Demographics

Per Japanese census data, the population of Saiki in 2020 is 66,851 people. Saiki has been conducting censuses since 1920.
| Year | Pop. | ±% |
| 1920 | 83,016 | — |
| 1925 | 85,352 | +2.8% |
| 1930 | 87,810 | +2.9% |
| 1935 | 91,816 | +4.6% |
| 1940 | 91,168 | −0.7% |
| 1945 | 110,387 | +21.1% |
| 1950 | 115,123 | +4.3% |
| 1955 | 118,236 | +2.7% |
| 1960 | 114,262 | −3.4% |
| 1965 | 105,046 | −8.1% |
| 1970 | 96,667 | −8.0% |
| Year | Pop. | ±% |
| 1975 | 96,317 | −0.4% |
| 1980 | 96,534 | +0.2% |
| 1985 | 95,907 | −0.6% |
| 1990 | 91,217 | −4.9% |
| 1995 | 88,116 | −3.4% |
| 2000 | 84,449 | −4.2% |
| 2005 | 80,297 | −4.9% |
| 2010 | 76,959 | −4.2% |
| 2015 | 72,211 | −6.2% |
| 2020 | 66,851 | −7.4% |
Saiki population statistics :

## History

The area of Saiki was part of ancient Bungo Province. Saiki began in the early Edo period as the castle town of Saiki Domain and was ruled by the Mōri clan until the Meiji restoration. (This Mōri clan was not related to the more famous Mōri clan of Chōshū Domain.) Following the Meiji restoration, the town of Saeki within Minamiamabe District, Ōita was established on May 1, 1889 with the creation of the modern municipalities system. In July 1916, the name of the town was changed from "Saeki" to "Saiki" to reflect the local dialect, with the kanji of the name remaining the same. In February 1934, the Saeki Naval Air Corps of the Imperial Japanese Navy was established in Saiki to conduct air patrols to ensure the safety of the Bungo Channel, where warships sailing from Kure Naval District located in the Seto Inland Sea exited to the Pacific Ocean. In 1937, Saiki annexed the villages of Tsuruoka and Kamikata. On April 29, 1941 - Saiki Town merged with the villages of Yahata, Oirishima, and Nishikamiura to form the city of Saiki City. Due to its military significance, the city was bombed six times during World War II. In 1955, Saiki annexed the villages of Aoyama, Shimogata and Kidachi. On Saiki merged with the neighboring towns of f Kamae, Kamiura, Tsurumi, Ume and Yayoi, and the villages Honjō, Naokawa and Yonōzu (all from Minamiamabe District) to create the new and expanded Saiki City. Minamiamabe District was dissolved as a result of this merger.

## Government

Saiki has a mayor-council form of government with a directly elected mayor and a unicameral city council of 25 members. Saiki contributes three members to the Ōita Prefectural Assembly. In terms of national politics, the city is part of the Ōita 2nd district of the lower house of the Diet of Japan.

## Economy

Saiki is a port city and a major regional commercial center.

## Education

Saiki has 21 public elementary schools and 12 public junior high schools operated by the city government. The city has two public high schools operated by the Ōita Prefectural Board of Education and one private high school. The prefecture operates one special education school for the handicapped.

## Transportation
### Railways

JR Kyushu - Nippō Main Line
* Azamui - Kariu - Kaizaki - Saiki - Kamioka - Naomi - Naokawa - Shigeoka - Sōtarō

### Highways

* Higashikyushu Expressway
* National Route 10
* National Route 217
* National Route 326
* National Route 388

## Sister cities

* Handan, China, friendship city since April 1994
* Gladstone, Queensland, Australia, sister city since September 1996
* Honolulu, Hawaii, United States, friendship city since December 2003

## Local attractions

* Saiki Castle - A castle ruin, a National Historic Site and one of the Continued Top 100 Japanese Castles.
* Saiki Chuo Hospital Stadium - During the 2002 World Cup, Saiki was the base camp for the Tunisia national football team.
* Fukashima (深島) is one of Japan's cat islands.

## Noted people from Saiki

* Nobuko Iwaki, politician
* Masatsugu Ono, author
* Riki Takeuchi, actor