is a Japanese city located in Nanyo, the region occupying the southern half of Ehime Prefecture. , the city had an estimated population of 40,723 in 19688 households and a population density of 94 persons per km².The total area of the city is . Geography Ōzu is located of the middle and lower reaches of the Hiji River, and in particular the basin at the confluence the Hiji River and the Yaochi River in the island Shikoku. It extends from a coastline on the Gulf of Iyo in the Seto Inland Sea to some points over 1000 meters above sea level at the headwaters of the Kawabe River, a tributary of the Hiji River. Neighbouring municipalities Ehime Prefecture Yawatahama Seiyo Iyo Uchiko Matsuyama Climate Ōzu has a Humid subtropical climate (Köppen Cfa) characterized by warm summers and cool winters with light snowfall. The average annual temperature in Ōzu is 15.2 °C. The average annual rainfall is 1644 mm with September as the wettest month. The temperatures are highest on average in January, at around 26.1 °C, and lowest in January, at around 4.6 °C. Demographics Per Japanese census data, the population of Ōzu has decreased steadily since the 1960s. History The area of Ōzu was part of ancient Iyo Province. During the Sengoku period, it was part of the holdings of Tōdō Takatora, who constructed Ōzu Castle on top of a previous fortification dating to the Kamakura period. In 1608, he was transferred and replaced by the Wakizaka clan, followed in 1617 by the Katō clan, who ruled the 66,000 koku Ōzu Domain under the Tokugawa shogunate. Ōzu developed in the Edo period as a castle town. The town of Ōzu was established within Kita District, Ehime with the establishment of the modern municipalities system on December 15, 1889. During the Meiji and Taishō periods (late 19th century, early 20th century), Ōzu saw great economic expansion due to thriving silk and Japanese wax candle (和蠟燭, warōsoku) industries. A robust timber trade also occurred during this time, with Hiji River serving as a transportation artery. However, transformations brought by the arrival of railways and motorways disrupted the balance of the local economic cycle. On September 1, 1954, town of Ōzu merged with the villages of Hirano (平野村), Awazu (粟津村), Miyoshi (三善村), Kamisukai (上須戒村), Minamikume (南久米村), Sugeta (菅田村), Niiya (新谷村), Yanagisawa (柳沢村) and Ōkawa (大川村) to form the city of Ōzu .