The river flows in the southeast 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 22 °C. The warmest month is October, when the average temperature is around 23 °C, and the coldest is February, at 21 °C.[4] The average annual rainfall is 2511 mm. The wettest month is January, with an average of 498 mm rainfall, and the driest is August, with 33 mm rainfall.[5]