The late 1970s witnessed a construction boom and a significant influx of migrants, which saw Mumbai overtake Calcutta as India’s most populous city. The city’s secular fabric was torn in 1992, after large scale sectarian violence caused extensive loss of life and property. A few months later, on March 12, simultaneous bombings at several city landmarks by the Mumbai underworld killed around three hundred people. In 1995, the city was renamed Mumbai, by the right wing Shiv Sena party government of Maharashtra, in keeping with their policy of renaming colonial institutions after historic local appellations.

Geography

Mumbai is located on Salsette Island, which lies at the mouth of Ulhas River off the western coast of India, in the coastal region known as the Konkan. Much of Mumbai is at sea level, and the average elevation ranges from 10 to 15 metres. The northern part of Mumbai is hilly, and the highest point of the city is at 450 metres (1,450 feet)[1]. Mumbai spans a total area of 468 km² (169 mi²).

Three lakes are located within the metropolitan limits - the Tulsi Lake, Vihar Lake and Powai Lake. The first two are located within the Borivali National Park, and supply part of the city’s drinking water. Mumbai also has three small rivers within the city limits originating in the National Park. The coastline of the city is indented with numerous creeks and bays. The eastern seaboard of Salsette Island is covered with large mangrove swamps, rich in biodiversity.

Soil cover in the city region is predominantly sandy due to its proximity to the sea. In the suburbs, the soil cover is largely alluvial and loamy. The underlying rock of the region is composed of black Deccan basalt flows, and their acid and basic variants dating back to the late Cretaceous and early Eocene eras. Mumbai sits on a seismically active zone owing to the presence of three fault lines in the vicinity. The area is classified as a Zone III region, which means an earthquake of up to magnitude 6.5 on the Richter scale may be expected.

Mumbai is classified as a metropolis of India, under the jurisdiction of the BrihanMumbai Municipal Corporation. It consists of two distinct regions - the city and the suburbs, which also form two separate districts of Maharashtra. The city region is also commonly referred to as the Island City.

Climate

The climate of the city, being in the tropical zone, and near the Arabian Sea, may be broadly classified into two main seasons - the humid season and the dry season. The humid season, between March and October, is characterised by high humidity and temperatures of over 30 °C (86 °F). The monsoon rains lash the city during the monsoon season (June to September), and supply most of the city’s annual rainfall of 2,200 mm (85 in). The maximum annual rainfall ever recorded was 3,452 mm (135.89 in) in 1954[4]. The highest rainfall recorded in a single day was 944 mm (37.16 in) on 2005-07-26.

The dry season, between November and February, is characterised by moderate levels of humidity and warm to cool weather. Cold northerly winds are responsible for a mild chill during January and February. Annual temperatures range from a high of 38 °C (100 °F) to a low of 11 °C (52 °F). The record high is 43 °C (108 °F) and record low is 7.4 °C (45 °F) on 1962-01-22.