Surat has a tropical savanna climate , moderated strongly by the Sea to the Gulf of Camboy. The summer begins in early March and lasts until June. April and May are the hottest months, the average maximum temperature being 37 °C (99 °F). Monsoon begins in late June and the city receives about 1,200 millimetres (47 in) of rain by the end of September, with the average maximum being 32 °C (90 °F) during those months. October and November see the retreat of the monsoon and a return of high temperatures until late November. Winter starts in December and ends in late February, with average mean temperatures of around 23 °C (73 °F), and negligible rain.
Since the 20th century, Surat has experienced some 20 floods. In 1968, most parts of the city were flooded and in 1994 a flood caused a country-wide plague outbreak, Surat being the epicenter. In 1998, 30 per cent of Surat had gone under water due to flooding in Tapti river following release of water from Ukai dam located 90 km from Surat and in Aug 2006 flood more than 95 per cent of the city was under Tapti river waters, killing more than 120 people, stranding tens of thousands in their homes without food or electricity and closing businesses and schools for weeks.