Introduction
City in Chūgoku, JapanKasaoka
笠岡市CityView of Kasaoka City
FlagEmblemInteractive map of KasaokaKasaokaLocation in JapanCoordinates: 34°30′14″N 133°30′36″E / 34.50389°N 133.51000°E / 34.50389; 133.51000CountryJapanRegionChūgoku (San'yō)PrefectureOkayamaGovernment • MayorNorimoto Mishima (current)Area • Total136.24 km2 (52.60 sq mi)Population (March 1, 2023) • Total45,404 • Density333.26/km2 (863.15/sq mi)Time zoneUTC+09:00 (JST)City hall address1-1 Chūō, Kasaoka-shi, Okayama-ken 714-8601ClimateCfaSymbolsFlowerChrysanthemumTreeGinkgo biloba
Kasaoka City Hall
Kasaoka Islands
Aerial view of Kasaoka city center
Kasaoka City Horseshoe Crab Museum
Kasaoka (笠岡市, Kasaoka-shi) is a city located in Okayama Prefecture, Japan. As of 1 March 2023[update], the city had an estimated population of 45,404 in 21,987 households and a population density of 330 inhabitants per square kilometre (850/sq mi). The total area of the city is 136.24 square kilometres (52.60 sq mi). The municipal district also includes 31 outlying islands including seven inhabited islands in the Kasaoka Islands archipelago in the Seto Inland Sea.
Geography
[edit]
Kasaoka is in the far southwestern corner of Okayama Prefecture, bordered by the Seto Inland Sea to the south and Hiroshima Prefecture to the west. It is mostly hilly and mountainous in the north, and consists of flat reclaimed land in the south. Urbanization is very diffuse, with the main urban concentration at the former port town of Kasaoka, with numerous hamlets scattered widely in narrow valley-shaped plains mostly in the central and northern areas. The tidal flats in the south are noted for endangered horseshoe crabs and the sea area between Kōnoshima and Nishi-Oshima has been designated as a national Natural Monument.
Adjoining municipalities[edit]
Hiroshima Prefecture
Fukuyama
Okayama Prefecture
Asakuchi
Ibara
Satoshō
Yakage
Climate[edit]
Kasaoka has a humid subtropical climate (Köppen climate classification Cfa). The average annual temperature in Kasaoka is 15.7 °C (60.3 °F). The average annual rainfall is 1,055.1 mm (41.54 in) with July as the wettest month. The temperatures are highest on average in August, at around 28.0 °C (82.4 °F), and lowest in January, at around 4.5 °C (40.1 °F). The highest temperature ever recorded in Kasaoka was 38.0 °C (100.4 °F) on 5 August 2021; the coldest temperature ever recorded was −7.3 °C (18.9 °F) on 27 February 1981.
Climate data for Kasaoka (1991−2020 normals, extremes 1979−present)
Month
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Year
Record high °C (°F)
16.5(61.7)
21.7(71.1)
25.0(77.0)
28.5(83.3)
32.2(90.0)
34.7(94.5)
38.0(100.4)
38.0(100.4)
37.6(99.7)
31.9(89.4)
26.7(80.1)
20.0(68.0)
38.0(100.4)
Mean daily maximum °C (°F)
9.4(48.9)
10.2(50.4)
13.5(56.3)
19.0(66.2)
23.9(75.0)
27.1(80.8)
31.1(88.0)
32.8(91.0)
28.7(83.7)
23.1(73.6)
17.2(63.0)
11.8(53.2)
20.7(69.2)
Daily mean °C (°F)
4.5(40.1)
5.1(41.2)
8.3(46.9)
13.6(56.5)
18.6(65.5)
22.6(72.7)
26.7(80.1)
28.0(82.4)
24.1(75.4)
18.0(64.4)
12.0(53.6)
6.7(44.1)
15.7(60.2)
Mean daily minimum °C (°F)
0.0(32.0)
0.3(32.5)
3.1(37.6)
8.2(46.8)
13.5(56.3)
18.7(65.7)
23.2(73.8)
24.2(75.6)
20.1(68.2)
13.5(56.3)
7.3(45.1)
2.2(36.0)
11.2(52.2)
Record low °C (°F)
−6.7(19.9)
−7.3(18.9)
−4.2(24.4)
−1.7(28.9)
3.6(38.5)
10.4(50.7)
15.8(60.4)
16.7(62.1)
9.1(48.4)
2.5(36.5)
−1.3(29.7)
−4.3(24.3)
−7.3(18.9)
Average precipitation mm (inches)
33.0(1.30)
41.6(1.64)
76.6(3.02)
81.2(3.20)
102.7(4.04)
160.7(6.33)
172.9(6.81)
80.0(3.15)
129.2(5.09)
87.5(3.44)
50.2(1.98)
39.6(1.56)
1,055.1(41.54)
Average precipitation days (≥ 1.0 mm)
4.7
6.5
8.7
8.5
8.7
10.5
9.4
6.9
8.3
6.9
5.8
5.6
90.5
Mean monthly sunshine hours
150.1
146.3
181.8
196.9
212.0
162.3
194.1
224.5
167.8
172.1
152.5
150.1
2,110.5
Source: Japan Meteorological Agency
Demographics[edit]
Per Japanese census data, the population of Kasaoka in 2020 is 46,088 people. Kasaoka has been conducting censuses since 1950.
Historical populationYearPop.±% 1950 75,372—     1955 73,552−2.4% 1960 68,987−6.2% 1965 63,778−7.6% 1970 62,405−2.2% 1975 63,413+1.6% 1980 61,917−2.4% 1985 60,598−2.1% 1990 59,619−1.6% 1995 60,478+1.4% 2000 59,300−1.9% 2005 57,272−3.4% 2010 54,256−5.3% 2015 50,568−6.8% 2020 46,088−8.9%Kasaoka population statistics