The river flows in the eastern area of Java with predominantly tropical monsoon climate (designated as Am in the Köppen-Geiger climate classification).[3] The annual average temperature in the area is 26 °C. The warmest month is October, when the average temperature is around 29 °C, and the coldest is January, at 23 °C.[4] The average annual rainfall is 2982 mm. The wettest month is March, with an average of 496 mm rainfall, and the driest is August, with 28 mm rainfall.[5]