The climate varies by altitude from hot in the low coastal areas to temperate in the higher elevations. There is a small area with a cold climate as part of the Tacan� Volcano. Precipitation also varies by altitude. The climate of the city area is hot and humid most of the year. The area is one of the rainiest in the world with annual rainfall of about 3,900mm drained by a number of rivers and streams that flow from the Sierra Madre de Chiapas over the coastal plain to the Pacific Ocean. The main rivers are the Huehuet�n, the Coat�n and the Cuilco. There are eighty two communities considered to be at high risk to natural disasters due to flooding of rivers and insufficient roadways to evacuate. Fifty two of these located on riverbanks of three rivers: Coat�n, Texcuyuapan and Cahoac�n. Much of the flood control of the area was damaged or destroyed by Hurricane Stan in 2005
