Introduction
City in Chūgoku, JapanIwakuni
Japanese: 岩国市CityView of Iwakuni from Iwakuni Castle (2010)
FlagEmblemInteractive map of IwakuniIwakuniLocation in JapanCoordinates: 34°9′59″N 132°13′8″E / 34.16639°N 132.21889°E / 34.16639; 132.21889CountryJapanRegionChūgoku (San'yō)PrefectureYamaguchiGovernment • MayorYoshihiko FukudaArea • Total873.72 km2 (337.35 sq mi)Population (June 1, 2023) • Total127,512 • Density156.95/km2 (406.5/sq mi)Time zoneUTC+09:00 (JST)City hall address1-14-51 Imazumachi, Iwakuni-shi, Yamaguchi-ken 740-8585ClimateCfaWebsiteOfficial websiteSymbolsFlowerCherry blossomTreeCinnamomum camphora
Iwakuni City Hall
Kintai Bridge
Iwakuni city center
Iwakuni (岩国市, Iwakuni-shi) is a city located in Yamaguchi Prefecture, Japan. As of 1 June 2023[update], the city had an estimated population of 127,512 in 65182 households and a population density of 157 people per km2. The total area of the city is 873.72 square kilometers (337.35 sq mi).
Geography
[edit]
Iwakuni is located in the southeastern Yamaguchi Prefecture, bordering Hiroshima Prefecture to the east and the Seto Inland Sea to the south. The Nishiki River flows through the center of the city.
Neighbouring municipalities[edit]
Hiroshima Prefecture
Hatsukaichi
Ōtake
Shimane Prefecture
Masuda
Yoshika
Yamaguchi Prefecture
Hikari
Shūnan
Tabuse
Waki
Yanai
Climate[edit]
Iwakuni has a humid subtropical climate (Köppen climate classification Cfa) with hot summers and cool winters. Precipitation is significant throughout the year, but is much higher from March to October, which encompasses the monsoon season from June to July, as well as peak typhoon season in September. The average annual temperature in Iwakuni is 15.1 °C (59.2 °F). The average annual rainfall is 1,781.4 mm (70.13 in) with July as the wettest month. The temperatures are highest on average in August, at around 26.9 °C (80.4 °F), and lowest in January, at around 4.2 °C (39.6 °F). The highest temperature ever recorded in Iwakuni was 39.0 °C (102.2 °F) on August 15, 2024; the coldest temperature ever recorded was −12.9 °C (8.8 °F) on February 19, 1977.
Climate data for Iwakuni (1991−2020 normals, extremes 1977−present)
Month
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Year
Record high °C (°F)
18.6(65.5)
21.4(70.5)
25.2(77.4)
29.7(85.5)
32.8(91.0)
35.5(95.9)
37.2(99.0)
37.8(100.0)
36.1(97.0)
32.4(90.3)
25.8(78.4)
21.3(70.3)
37.8(100.0)
Mean daily maximum °C (°F)
9.0(48.2)
9.9(49.8)
13.5(56.3)
19.0(66.2)
23.7(74.7)
26.4(79.5)
30.5(86.9)
31.9(89.4)
28.1(82.6)
22.6(72.7)
16.8(62.2)
11.4(52.5)
20.2(68.4)
Daily mean °C (°F)
4.2(39.6)
4.9(40.8)
8.2(46.8)
13.4(56.1)
18.1(64.6)
21.8(71.2)
25.9(78.6)
26.9(80.4)
23.1(73.6)
17.3(63.1)
11.4(52.5)
6.3(43.3)
15.1(59.2)
Mean daily minimum °C (°F)
0.1(32.2)
0.5(32.9)
3.1(37.6)
8.0(46.4)
12.9(55.2)
17.9(64.2)
22.3(72.1)
23.0(73.4)
19.0(66.2)
12.7(54.9)
6.9(44.4)
2.1(35.8)
10.7(51.3)
Record low °C (°F)
−7.1(19.2)
−8.3(17.1)
−5.0(23.0)
−1.1(30.0)
3.4(38.1)
9.3(48.7)
14.8(58.6)
15.8(60.4)
7.5(45.5)
2.0(35.6)
−1.1(30.0)
−5.2(22.6)
−8.3(17.1)
Average precipitation mm (inches)
54.3(2.14)
79.9(3.15)
145.6(5.73)
172.8(6.80)
187.5(7.38)
274.1(10.79)
292.1(11.50)
154.9(6.10)
182.4(7.18)
113.7(4.48)
77.5(3.05)
62.5(2.46)
1,781.4(70.13)
Average precipitation days (≥ 1.0 mm)
6.2
7.3
9.7
9.3
9.4
11.8
11.0
8.5
8.9
6.8
6.4
6.4
101.7
Mean monthly sunshine hours
153.7
150.3
181.3
204.4
220.8
151.8
176.2
217.8
167.0
179.8
159.4
156.5
2,127.2
Source: Japan Meteorological Agency
Climate data for Kuga, Iwakuni (1991−2020 normals, extremes 1977−present)
Month
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Year
Record high °C (°F)
18.8(65.8)
21.8(71.2)
24.3(75.7)
29.2(84.6)
32.4(90.3)
35.2(95.4)
38.1(100.6)
38.1(100.6)
36.2(97.2)
31.5(88.7)
26.8(80.2)
20.5(68.9)
38.1(100.6)
Mean daily maximum °C (°F)
9.3(48.7)
10.5(50.9)
14.2(57.6)
19.8(67.6)
24.5(76.1)
27.0(80.6)
30.8(87.4)
32.2(90.0)
28.5(83.3)
23.1(73.6)
17.2(63.0)
11.6(52.9)
20.7(69.3)
Daily mean °C (°F)
3.6(38.5)
4.6(40.3)
8.1(46.6)
13.3(55.9)
18.1(64.6)
21.9(71.4)
25.8(78.4)
26.8(80.2)
23.1(73.6)
17.1(62.8)
11.0(51.8)
5.6(42.1)
14.9(58.9)
Mean daily minimum °C (°F)
−1.2(29.8)
−0.6(30.9)
2.3(36.1)
7.1(44.8)
12.3(54.1)
17.7(63.9)
22.1(71.8)
22.8(73.0)
18.8(65.8)
12.1(53.8)
5.7(42.3)
0.6(33.1)
10.0(49.9)
Record low °C (°F)
−8.9(16.0)
−11.5(11.3)
−6.4(20.5)
−3.0(26.6)
1.7(35.1)
7.9(46.2)
14.6(58.3)
15.5(59.9)
7.2(45.0)
0.0(32.0)
−2.6(27.3)
−7.2(19.0)
−11.5(11.3)
Average precipitation mm (inches)
62.0(2.44)
90.7(3.57)
158.9(6.26)
186.8(7.35)
211.0(8.31)
292.2(11.50)
333.6(13.13)
166.4(6.55)
183.6(7.23)
110.3(4.34)
82.9(3.26)
66.0(2.60)
1,944.3(76.55)
Average precipitation days (≥ 1.0 mm)
6.6
8.0
10.0
9.8
9.4
12.0
11.3
8.9
9.1
6.6
7.1
6.7
105.5
Mean monthly sunshine hours
147.0
144.0
176.6
190.9
201.6
139.4
156.7
194.7
162.9
178.1
154.9
149.0
1,989.1
Source: Japan Meteorological Agency
Climate data for Hirose, Iwakuni (1991−2020 normals, extremes 1976−present)
Month
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Year
Record high °C (°F)
17.6(63.7)
21.4(70.5)
27.1(80.8)
30.3(86.5)
34.4(93.9)
36.2(97.2)
38.3(100.9)
39.0(102.2)
36.8(98.2)
32.0(89.6)
29.1(84.4)
20.5(68.9)
39.0(102.2)
Mean daily maximum °C (°F)
8.4(47.1)
9.9(49.8)
14.0(57.2)
19.8(67.6)
24.6(76.3)
27.1(80.8)
30.7(87.3)
32.1(89.8)
28.1(82.6)
22.6(72.7)
16.6(61.9)
10.7(51.3)
20.4(68.7)
Daily mean °C (°F)
2.8(37.0)
3.8(38.8)
7.3(45.1)
12.7(54.9)
17.5(63.5)
21.4(70.5)
25.3(77.5)
26.1(79.0)
22.1(71.8)
16.0(60.8)
10.0(50.0)
4.8(40.6)
14.2(57.5)
Mean daily minimum °C (°F)
−1.0(30.2)
−0.7(30.7)
2.0(35.6)
6.6(43.9)
11.6(52.9)
17.0(62.6)
21.5(70.7)
22.1(71.8)
18.0(64.4)
11.5(52.7)
5.6(42.1)
1.0(33.8)
9.6(49.3)
Record low °C (°F)
−10.3(13.5)
−12.9(8.8)
−6.3(20.7)
−3.0(26.6)
0.1(32.2)
5.4(41.7)
12.9(55.2)
13.7(56.7)
4.9(40.8)
0.2(32.4)
−2.8(27.0)
−8.4(16.9)
−12.9(8.8)
Average precipitation mm (inches)
85.8(3.38)
108.1(4.26)
181.9(7.16)
210.6(8.29)
246.8(9.72)
311.3(12.26)
370.3(14.58)
207.7(8.18)
213.4(8.40)
126.7(4.99)
97.0(3.82)
89.9(3.54)
2,263.4(89.11)
Average precipitation days (≥ 1.0 mm)
10.6
10.9
11.7
10.2
9.4
12.6
12.6
10.7
10.1
7.2
8.3
10.5
124.8
Mean monthly sunshine hours
106.9
119.9
162.7
182.7
207.5
144.7
146.0
180.0
151.3
165.1
129.0
106.3
1,802
Source: Japan Meteorological Agency
Demographics[edit]
As of August 1, 2016, the city has an estimated population of 137,128 (which the city has decreased in population by 50,000 over the last 25 years) and a population density of 156.95 of persons per km2. The total area is 873.72 km2.
Historical populationYearPop.±% 1950 149,965—     1955 162,518+8.4% 1960 165,498+1.8% 1965 162,015−2.1% 1970 157,338−2.9% 1975 161,103+2.4% 1980 163,692+1.6% 1985 161,682−1.2% 1990 158,293−2.1% 1995 156,347−1.2% 2000 153,985−1.5% 2005 149,702−2.8% 2010 143,888−3.9% 2015 136,757−5.0% 2020 129,125−5.6%Iwakuni population statistics
