Geography Thailand has a land area of 513.5115 sq km bordered by Malaysia, Myanmar, Laos and Cambodia. Population Total 63.079.765 - approximately 6.255.023 living in Bangkok. Climate Temperature varies from 38 C to 19 C. Average temperatures are about 29 C. Humidity from 60% to 85%. Language Thai is the national language. English is widely understood in bigger cities. Scuba Diving Dive tours Thailand. Scuba liveaboard Similan. Dive safari similans. Diving Khao Lak. Tauchen Phuket.