The city of Islamabad expanses an area of 906 square kilometres (350 sq mi).
A further 2,717 square kilometres (1,049 sq mi) area is known as the Specified Area, with the Margala Hills in the north and northeast.
The wettest month is July, with heavy rainfalls and evening thunderstorms with the possibility of cloudburst and flooding. Islamabad's micro-climate is regulated by three artificial reservoirs: Rawal, Simli, and Khanpur Dam.
The latter is located on the Haro River near the town of Khanpur, about 40 kilometres (25 mi) from Islamabad.
In the city, temperatures stay mild, with snowfall over the higher elevations points on nearby hill stations, notably Murree and Nathia Gali.
The city has the highest cost of living in Pakistan, and its population is dominated by middle and upper middle class citizens.Simli Dam is 30 kilometres (19 mi) north of Islamabad.