Tsu has a humid subtropical climate (Köppen Cfa) characterized by warm summers and cool winters with light to no snowfall.

During the Edo period, it became a popular stopping point for travelers to Ise Grand Shrine, about 40 km to the southeast.

The city borders gradually expanded, with Tsu annexing the neighboring villages of Tatebe and Tosa in 1909, Shinmachi in 1934, Fujimi in 1936, Takachaya in 1939 and Anto, Kanbe and Kushigata in 1943.

In 1953, Tsu annexed the neighboring villages of Kumozu in 1953, Isshinden, Shiratsuka, Kurima, and Katada in 1954 and Toyosato in 1973.

Tsu has a mayor-council form of government with a directly elected mayor and a unicameral city council of 34 members.

In terms of national politics, the city is part of Mie 1st district of the lower house of the Diet of Japan.