Saudi Arabia is located in the Middle East between the Red Sea and Persian Gulf. It has a typical desert climate that is very hot during the day and cold at night. Nearly 95% of the country is covered by desert. Saudi Arabia has a population of over 20 million people, most of whom are Arab and nearly all (99%) are Muslim. The culture revolves around Islam, and the official language is Arabic. Saudi Arabia has an oil-based economy and possesses over 25% of the world's proven petroleum reserves, making it the largest exporter of oil.