Niihama is positioned in the north-center area of the island of
Shikoku, in the eastern part of Ehime Prefecture. Niihama is enveloped by mountains to the south and east, hills to the west, and the
Seto Inland Sea to the north. The Kokuryo River flows from the mountains to the Seto Inland Sea and divides the city into an areas east of the river (
kawahigashi) and west of the river (
kawanishi). Being surrounded by mountains, Niihama feels geographically isolated from its closest neighbors,
Saijō to the west and
Shikokuchūō to the east. The border with
Kōchi Prefecture lies in the mountains far south of the center of town. The island of
Ōshima, northeast of the main part of the city, also is part of Niihama. The largely mountainous village of
Besshi joined the city of Niihama in 2003 greatly increasing the size of the city.
Neighbouring municipalities Ehime Prefecture •
Saijō •
Shikokuchūō Kōchi Prefecture •
Ino •
Ōkawa Climate Niihama has a
humid subtropical climate (Köppen
Cfa) characterized by warm summers and cool winters with light snowfall. The average annual temperature in Niihama is 13.2 °C. The average annual rainfall is 1839 mm with September as the wettest month. The temperatures are highest on average in August, at around 24.4 °C, and lowest in January, at around 2.0 °C. }} ==Demographics==