The river flows in the southwest area of Java with predominantly tropical monsoon climate (designated as Am in the Köppen-Geiger climate classification).[2] The annual average temperature in the area is 24 °C. The warmest month is January, when the average temperature is around 27 °C, and the coldest is July, at 23 °C.[3] The average annual rainfall is 2970 mm. The wettest month is January, with an average of 537 mm rainfall, and the driest is September, with 22 mm rainfall.[4]