Lusi River is a river in northern Central Java, Indonesia, about 400 km east of the capital Jakarta.

[1][2] It is a tributary of the Serang River, meeting after passing the city of Purwodadi.

[3] Lusi River is one of the longest in Central Java, with a length of 208.5 km and the basin size of 3656.78 km².

[4] The river flows in the central area of Java with predominantly tropical monsoon climate (designated as Am in the Köppen-Geiger climate classification).

The warmest month is October, when the average temperature is around 28 °C, and the coldest is January, at 24 °C.