Trang is located at 7 degrees 34 minutes N latitude and 99 degrees 37 minutes E longitude of the Andaman Sea, with a total land area of 5,215 km2, surrounded with mountains and waves, bordering on Amphor Thung Song, Nakhon Si Thammarat, and Amphor Klong Thom, Krabi, to the north, Amphor Thung Wha, Satun, Amphor Ratphum, Songkhlia, and Chong Malaka, the Indian Ocean to the south, Amphor Kuan Kanun, Amphor Kong Wha, Sub Amphor Tamod, Phatthalung, to the east, and Amphor Klong Thom, Amphor Koh Lanta, Krabi, and the Indian Ocean to the west. Such location truly makes Trang a beautiful rich City. Its overall geographical landscape, characterised by high and low formations, sloping down to the coast of the Andaman Sea, is indeed a unique natural charm. At present, Trang is broken down administratively into 8 Amphors (districts) as follows: Amphor Muang Trang, Amphor Kantang, Amphor Paliean, Amphor Yan Ta Khao, Amphor Sikao, Amphor Huay Yod, Amphor Wang Wiset, Amphor Nayong and 2 King Amphors (sub-districts): Hadsumran and Rasda.
Although it rains all year round in Trang because of high humidity influenced by the Northeast monsoon, October to January, and the Southwest monsoon, May to September, but at the end of November or early December, Trang will be blessed with a cool breeze from the Northeast monsoon with no rain. Such nice climate coincides with the King's birthday celebration to be organised at the City Hall. The ceremony is a significant event of every year, and the breeze is called "the King's birthday breeze". In February, the temperature will be as low as 15C, but will go up as high as 39C in April, but only for a short time. After that, the weather will return to normal, at 27.4C, which is the annual mean temperature of the city.
From the bird's eye view, Trang is surrounded by mountains on 3 sides, Khao Na Dang and Khao Noi Juji in the north, and Khao Bantad Mountain range in the south and the east which have long been, and will continue to be, fortifications for the city. The forest on Khao Bantad mountain range is still a virgin and rich forest, occupying an area of almost 20 percent of the city area. It is a large land forest and sources of 2 main rivers, the Trang River and the Paliean River. The Trang River originates from Khao Bantad mountain range in Nakhon Si Thammarat It is about 123 km. long, flowing through Trang into the Andaman Sea at Amphor Kantang. The Paliean River originates from Khao Bantad mountain range in Phatthalung. It is about 588 km. long, flowing through Amphor Yan Ta Khao and Amphor Paliean into the Andaman Sea at Amphor Paliean. These 2 main rivers of Trang contribute and distribute water to various areas all over the city all year round through their 14 tributaries and over 100 waterways. Trang has, therefore, never suffered from drought before. The area along the West Coast of the city is covered with mangrove forest, a major source of food chain for plants. The mangrove forest occupies an area of about 233,025 Rai. It is an extremely valuable ecological system, which still remains in its natural condition to date. Trang citizens are aware of the great value of the mangrove forest, and plan to conserve and revive it to its original or a better condition, for sustainable natural fertility.