Thailand

Thailand is a country in Southeast Asia.

It is warm all year long. It has green mountains and wide rice fields. A long, thin strip of land stretches far to the south. The capital city is called Bangkok.

Thailand is a country in Southeast Asia, about the same size as Spain or France. Its main part is in the north, and a long, narrow peninsula runs south to Malaysia. Its neighbors are Myanmar, Laos, Cambodia and Malaysia.

Thailand lies completely within the tropics, and it is warm all year, with average temperatures between 25 and 29 °C. It has forested hills in the north, rice fields on the central plains, a broad plateau in the northeast and sandy coasts in the south. Until 1939 the country was called Siam. Its capital is Bangkok, and about 65.8 million people were registered as living in Thailand at the end of 2025.

Thailand, about the size of Spain or France (about 513,000 km²), lies wholly within the tropics. Britannica divides it into five physiographic regions: the folded mountains of the north and west, the Khorat Plateau in the northeast, the Chao Phraya basin in the center, the maritime southeast and the long, slender peninsula in the southwest. The main body is bordered by Myanmar to the west, Laos to the north and east, Cambodia to the southeast and the Gulf of Thailand to the south.

Until the second half of the 20th century Thailand was mainly agricultural, but since the 1960s more and more people have moved to Bangkok and other cities. Thailand's Central Registration Office counted 65,809,011 people on December 31, 2025, including 64,820,708 Thai nationals, about 142,000 fewer than a year before; the World Bank's estimate for 2025 is higher, 71,619,863. Siam, as the country was officially called until 1939, was never brought under European colonial domination.

Bangkok is the biggest city in Thailand.

It has tall towers and busy roads. Long ago, the capital was Ayutthaya. Its old brick towers still stand. Chiang Mai is a city in the northern hills.

Bangkok became the capital in 1782, when King Rama I moved his court across the Chao Phraya River to what was then a small village. Today the greater Bangkok area is the country's leading urban center. Chiang Mai, in the north, and Nakhon Ratchasima, in the northeast, are other big cities.

UNESCO lists three ancient places as World Heritage Sites. Sukhothai was the capital of the first Kingdom of Siam in the 1200s and 1300s. Ayutthaya, founded around 1350, became the second capital; its ruins of brick towers and huge monasteries show how grand it once was. Ban Chiang, in the northeast, is considered the most important prehistoric settlement yet found in Southeast Asia.

Rama I, founder of the Chakkri dynasty, moved the capital across the Chao Phraya from Thon Buri to Bangkok, then a small village, in 1782. Britannica notes that the greater Bangkok metropolitan area remains the preeminent urban center, with other sizable cities such as Chiang Mai, Nakhon Ratchasima (Khorat), Khon Kaen, Udon Thani, Pattaya and Hat Yai.

UNESCO inscribed the Historic Town of Sukhothai in 1991: capital of the first Kingdom of Siam in the 13th and 14th centuries, whose monuments illustrate the beginnings of Thai architecture in what is called the Sukhothai style. Ayutthaya (1991), founded about 1350 as the second Siamese capital, was destroyed by the Burmese in the 18th century; its remains, with prang (reliquary towers) and gigantic monasteries, give an idea of its past splendor. Ban Chiang (1992), in the northeast, preserves the earliest evidence in the region of farming and of making and using metals.

Thailand has two big rivers.

The Chao Phraya flows through the middle. The Mekong flows along the edge. Rainy season comes in summer. The tallest mountain is called Doi Inthanon.

In the north, long mountain ridges run down toward Malaysia. The highest peak, Doi Inthanon, near Chiang Mai, is 2,565 meters tall. Rivers from the northern mountains, the Ping (with the Wang), the Yom and the Nan, join to form the Chao Phraya, Thailand's main river, which flows across the central plain to the Gulf of Thailand. In the east, the Mekong forms much of the border with Laos.

The weather follows the monsoon winds. From May, warm, wet winds from the Indian Ocean bring heavy rain, with the most in September. From November to February, cooler, drier winds blow from the northeast. March and April are hot and dry. Average temperatures stay between 25 and 29 °C through the year.

The northern mountains continue the uplift that formed the Himalayas, with long granitic ridges where molten rock forced its way through older sediments; peaks average about 1,600 m, and Doi Inthanon, near Chiang Mai, is the highest (2,565 m, the height the Tourism Authority of Thailand gives; Britannica gives 2,585 m). The Khorat Plateau, a tilted tableland bounded by the Mekong, slopes from about 200 m in the northwest to 90 m in the southeast. The Ping (with its tributary the Wang), Yom and Nan merge to form the Chao Phraya, whose delta was once part of the Gulf of Thailand and has been filled by sediment; its wet-season flooding supports rice farming.

The climate is tropical monsoon: the southwest monsoon from May brings heavy rain peaking in September, the northeast monsoon from November to February brings cooler, drier air, and March and April are hot and dry. Temperatures average 25–29 °C, with occasional frost on northern heights in December. Rain shadows matter: Ranong on the west coast of the peninsula receives about 4,000 mm a year, Hua Hin on the east coast less than 1,000 mm.

Elephants and tigers live in Thailand's big forests.

Gibbons live in the forests too. King cobras live in the wild. Lotus flowers grow in the ponds.

Thailand's forests along the border with Myanmar are home to elephants and tigers. In the Dong Phayayen-Khao Yai forests in the northeast, UNESCO counts more than 800 kinds of animals, including 112 kinds of mammals, two of them gibbons, and 392 kinds of birds. King cobras are still common in the wild, and crocodiles live in the south.

In the mid-1900s forests covered more than half of Thailand, but today they cover less than a third. Rhinoceroses, tapirs and herds of wild elephants that used to live in many parts of the country have nearly disappeared. People once used elephants to move heavy loads; after logging was banned in 1989, many tame elephants began working with tourists instead.

UNESCO's Thungyai-Huai Kha Khaeng Wildlife Sanctuaries (1991), more than 600,000 ha along the Myanmar border, hold examples of almost all the forest types of continental Southeast Asia and 77 percent of the region's large mammals (especially elephants and tigers), 50 percent of its large birds and 33 percent of its land vertebrates. The Dong Phayayen-Khao Yai Forest Complex (2005), 230 km from Khao Yai to the Cambodian border, has more than 800 animal species, including 112 mammals (two of them gibbons), 392 birds and 200 reptiles and amphibians, among them 19 vulnerable, four endangered and one critically endangered species.

Britannica records that forest cover fell from more than half of the land in the mid-20th century to less than one-third, and that rhinoceroses, tapirs, wild elephant herds, gibbons and some monkeys and birds have suffered from deforestation and the trade in exotic animals. King cobras and several venomous water snakes remain common in the wild, crocodiles survive in the south, and domesticated elephants moved into tourism after the 1989 logging ban.

About 66 million people live in Thailand.

Most people speak Thai. Rice is a very important food. People in the north often eat sticky rice. Fish sauce goes into many dishes.

About 65.8 million people were registered in Thailand at the end of 2025. Nearly everyone can speak and write Standard Thai, which is taught in schools, but many families speak other languages at home. Nearly one in four people, mostly in the northeast, speaks dialects related to the Lao language of Laos. Malay is spoken in the far south, and hill peoples such as the Karen and Hmong live in the north and west.

Rice is at the heart of Thai cooking, and fish sauce is used in many dishes the way soy sauce is used in Chinese cooking. Noodles came from Chinese cooking. In the north and northeast, people prefer sticky glutinous rice. Most Thai people are Buddhists, and almost every settlement has a temple-monastery, where monks live and communal rituals take place.

The civil register counted 65,809,011 people at the end of 2025. Standard Thai, based on the speech of central Thailand, is the national language, learned through schools and the media; nearly one-fourth of the population, mostly on the Khorat Plateau, speaks dialects related to Lao, Khmer is spoken in the northeast and east, a Malay dialect in the far southern provinces, and Teochew, Hokkien, Hainanese and Cantonese among descendants of Chinese migrants. Highland peoples include the Karen, Lahu, Lisu, Hmong and Iu-Mien. The vast majority follow Theravada Buddhism, which came from Sri Lanka, and a small but significant Muslim minority lives mainly in the south and around Bangkok.

Rice is fundamental to Thai cuisine; fish sauce is a basic ingredient, and noodles were adopted from Chinese cooking. The peoples of Lan Na in the north and Isan in the northeast prefer glutinous rice to fragrant long-grain rice, and Lao dishes have become popular nationwide since the 1980s. Britannica notes that since the 1970s Thai cuisine has spread throughout the world.