Of the cropped area, only are irrigated—nearly half by wells and tanks, and 40 percent by government canals. The district had a population of 4.2 million in 1991, of which 52 percent was rural. There were 1,530 villages in the district. Its average rainfall is , most of which falls during the monsoon months (July to October). The area adjacent to the Western Ghats gets more rain than areas further east. The Daund and Indapur talukas experience more-frequent droughts than Maval, on the district's western edge. Temperatures are moderate and rainfall is unpredictable, in tune with the Indian monsoon. Summers, from early March to July, are dry and hot. Temperatures range from , and may reach . Winter runs from November to February. Temperatures usually hover around , sometimes dipping to . June is the driest month, and the agricultural sector is considered vulnerable until 20 September. The Bhima River, the Krishna River's main tributary, rises in the Western Ghats and flows east. All the district's rivers (the Pushpavati, Krushnavati, Kukadi, Meena, Ghod, Bhama, Andhra, Indrayani, Pavna, Mula, Mutha, Ambi, Mose, Shivganga, Kanandi, Gunjavni, Velvandi, Nira, Karha and Velu) flow into the Bhima or its tributaries. Major dams are on the Kukadi, Pushpavati, Ghod, Bhima, Pavna, Bhama, Mula, Mutha (the Temghar and Khadakwasla Dams) and Mose. The district has two municipal corporations: the Pune Municipal Corporation (PMC) and Pimpri Chinchwad Municipal Corporation (PCMC). Pimpri Chinchwad is west of Pune on the Pune-Mumbai national highway, and its corporation covers Nigdi, Akurdi, Pimpri, Chinchwad and Bhosari. The region was zoned for industrial development by the state of Maharashtra in the early 1960s. Pune district is divided into 15 talukas (Junnar taluka, Ambegaon taluka, Khed taluka, Maval taluka, Mulshi taluka, Velhe taluka, Bhor taluka, Haveli taluka, Purandar taluka, Pimpri Chinchwad taluka, Pune City taluka, Indapur taluka, Daund taluka, Baramati taluka and Shirur taluka) and 13 panchayat samitis.