Singapore is a very small, heavily urbanised, island city-state in Southeast Asia, located at the end of the Malayan Peninsula between Malaysia and Indonesia. Singapore has a total land area of . The Singapore area comprises mainland and other islands. The mainland of Singapore measures from east to west and from north to south with of coastline. These figures are based on High Water Mark cadastral survey boundaries. It has an exclusive economic zone of . Singapore is separated from Indonesia by the Singapore Strait and from Malaysia by the Straits of Johor. Topography Singapore's main territory is a diamond-shaped island, although its territory includes surrounding smaller islands. The farthest outlying island is Pedra Branca. Of Singapore's dozens of smaller islands, Jurong Island, Pulau Tekong, Pulau Ubin and Sentosa are the larger ones. Most of Singapore is no more than 15 metres above sea level. The highest point of Singapore is Bukit Timah Hill, with a height from ground of 165 m (538 ft) and made up of igneous rock, granite. Hills and valleys of sedimentary rock dominate the northwest, while the eastern region consists of sandy and flatter land. Singapore has no natural lakes, but reservoirs and water catchment areas have been constructed to store fresh water for Singapore's water supply. Singapore has reclaimed land with earth obtained from its own hills, the seabed, and neighbouring countries. As a result, Singapore's land area has grown from 581.5 km² in the 1960s to 725.7 km² today, and will increase slightly more due to construction of sea polder and barrage to deal with the ever rising sea level. Climate Singapore is one-and-a-half degrees north of the equator, lying entirely between the 1st and 2nd parallels. Singapore's climate is classified as tropical rainforest climate (Köppen climate classification Af), with no true distinct seasons. Owing to its geographical location and maritime exposure, its climate is characterized by uniform temperature and pressure, high humidity and abundant rainfall. Therefore, it is almost always warm and wet. The average annual rainfall is around . The highest 24-hour rainfall figures ever recorded in history were (2 December 1978) at Paya Lebar, (1969) and (19 December 2006). The temperature hovers around a diurnal range of a minimum of and a maximum of . May is the hottest month of the year in Singapore, followed by June. This is due to light winds and strong sunshine during those months.