which are known as tropical wet and dry because of the distinctly marked seasonal differences. Cambodia has a temperature range from and experiences tropical monsoons. Southwest monsoons blow inland bringing moisture-laden winds from the Gulf of Thailand and Indian Ocean from May to October. The northeast monsoon ushers in the dry season, which lasts from November to April. The country experiences the heaviest precipitation from September to October with the driest period occurring from January to February. According to the International Development Research Center and The United Nations, Cambodia is considered Southeast Asia's most vulnerable country to the effects of climate change, alongside the Philippines. Nearly all provinces in Cambodia are affected by climate change. Rural coastal populations are particularly at risk. Shortages of clean water, extreme flooding, mudslides, higher sea levels and potentially destructive storms are of particular concern, according to the Cambodia Climate Change Alliance. Climate change has also had a major impact on water levels, ecology and productivity of the Tonlé Sap in recent years, affecting the food security and agriculture of a large proportion of Cambodia's population. Cambodia has two distinct seasons. The rainy season, which runs from May to October, can see temperatures drop to and is generally accompanied with high humidity. The dry season lasts from November to April when temperatures can rise up to around April. Disastrous flooding occurred in 2001 and again in 2002, with some degree of flooding almost every year. Severe flooding also affected 17 provinces in Cambodia during the 2020 Pacific typhoon season. Biodiversity and conservation Cambodia's biodiversity is largely founded on its seasonal tropical forests, containing some 180 recorded tree species, and riparian ecosystems. There are 212 mammal species, 536 bird species, 240 reptile species, 850 freshwater fish species (Tonle Sap Lake area), and 435 marine fish species recorded by science. Much of this biodiversity is contained around the Tonle Sap Lake and the surrounding biosphere. The Tonle Sap Biosphere Reserve is a reserve surrounding the Tonle Sap lake. It encompasses the lake and nine provinces: Kampong Thom, Siem Reap, Battambang, Pursat, Kampong Chhnang, Banteay Meanchey, Pailin, Oddar Meanchey and Preah Vihear. In 1997, it was successfully nominated as a UNESCO Biosphere Reserve. Other key habitats include the evergreen and dry Dipterocarp forests of Mondolkiri province, protected by Keo Seima Wildlife Sanctuary, Phnom Prich Wildlife Sanctuary, and Srepok Wildlife Sanctuary, as well as Ratanakiri province, and the Cardamom