The modern name of the city came through the Sogdian Tarmi? dating back to Old Iraniantara-mai?a, which means "a place of transition" (tara-crossing, crossing; mai?a-place). In ancient times there was an important crossing on the Amu Darya river.
Some link the name of the city to Greek thermos "hot", tracing its name back to Alexander the Great. Others suggest that it came from Sanskrit taramato, meaning "on the river bank".
In ancient times
The date of the founding of the city of Old Termez, located a few kilometers west of the modern city, is not known. In April 2002 there was a celebration of the 2,500th anniversary of the city of Termez. 
The city was known to Achaemenids in the 6th century BC. In 329 BC Alexander the Great conquered Termez. Later Demetrius, the founder of Greco-Bactrian kingdom named it Demetris. As part of the Kushan Empire (1st to 3rd century BC) The city was called Ta-li-mi (in the Chinese Tu-mi, Tami. During this period, the city became an important center of Buddhism.
Walls of Old Termez.
In the 5th and 6th centuries the city was ruled by Hephthalites and Sassanids.
In the 7th century the city was ruled by the native Termez shah dynasty. It was a vassal of Gokturks.
From the 9th to the 12th centuries Termez was a big city and a cultural centre and was popular for shopping and crafts. At this time the length of the fortifications of the city was 16 kilometres (10 miles) long with nine gates. During this period Termez was a part of the Ghaznavids, Seljuk and Karakhanids. In 1206 the town became part of the state Khorezmshahs.
In 1220 after a two-day siege, the city was destroyed by the troops of Genghis Khan.
Ibn Battuta noted the city had "fine buildings and bazaars, traversed by canals, and with many gardens."
In the second half of the 13th century Termez was restored to the east, on the right bank of Surxondaryo River, as part of the Timurid empire, then Shaybanids. By the second half of the 18th century the city was abandoned. The only inhabited villages were Salavat and Pattakesar (Pattagissar) in the vicinity of the ancient city.
In the Russian Empire and the Soviet Union
Elephant among Lotus Flowers, Old Termez, 2nd-3rd cent CE.
In 1992 the Pedagogical Institute was upgraded to Termez State University.
The military airfield in Termez is used by the air forces of Germany for transiting goods to Afghanistan.
In July 2009 It was decided to establish a "Termez regional railway junction" which will be one of the main places in the planned transit of non-lethal NATO supplies to Afghanistan. The transit will be through Russia, Kazakhstan and Uzbekistan bypassing Turkmenistan through the railway in 2009 Tashguzar-Boysun-Kumkurgan. 
In June 2015, the Prime Minister of Pakistan Nawaz Sharif announced the construction of the Gwadar-Termez Highway, which would connect Uzbekistan via a road network to the Arabian sea at Gwadar Port in Pakistan.
Culture and Historical Sites
Termez Archaeological Museum opened in 2002 to commemorate the 2,500th anniversary of Termez. It exhibits archaeological finds and other historic artefacts from sites across Surxondaryo Region. The modern building has a turquoise domed roof and an attractively tiled facade. It is one of the largest and best museums in Uzbekistan. There are around 27,000 items in the collection.
Much of the museum's collection focuses on Termez's Buddhist history, in particular the Graeco-Bactrian and Kushan eras. There are scale models of archeological sites including Kampir Tepe, Fayaz Tepe, and Khalchayan; and magnificent wall paintings and sculptures, as well as coins, ceramics, and even ancient chess sets.
Kyr Kyz (The 40 Girls Fortress) takes its name from a Central Asian legend about a princess and her 40 companions who defended their land against invaders. Although this monument is called a fortress, archeologists believe it was actually either a caravanserai or a summer palace. It was built during the 9th century in the Samanid period. Although it is now in ruins, it is still possible to see the 54m long mud brick walls, which in places are two storeys high. One section has been restored so you are able to compare the old and the new.
The Al Hakim At-Termizi architectural complex dates from the 10th to 15th centuries. It is centred on the mud brick mausoleum of Al Hakim At-Termizi, a Sufi saint, jurist, and writer who died in Termez in 859. The site was expanded and improved at the instigation of Timur's son, Shah Rukh, in the 15th century.
The Sultan Saodat architectural ensemble developed in stages between the 10th and 17th centuries. It was the family necropolis of the Termez Sayyids, a politically and religiously influential local dynasty which claimed descent from Ali. There are approximately 120 graves in the complex, as well as a number of religious buildings. The mortar holding the mud bricks together is an unusual mixture of clay, egg yolk, camels' blood, and milk. There are pre-Islamic decorative symbols on some of the buildings, including a Zorastrian star motif which represents infinity and fertility.
The Kokil Dara Khanagha was built by Abdullah Khan II of Bukhara in the 16th century. The building was created as a resting place for itinerant Sufidervishes and other holy men. It has cultural links with various buildings in Afghanistan, including the styling of the vaulted ceiling. There is no central courtyard as this order of Sufis didn't whirl, but instead focused on quiet, solitary meditation.
Kara Tepe is a rock cut Buddhist temple complex founded in the 2nd century AD on the hills outside Termez. It is right on the Uzbek-Afghan border, and so a permit is required to visit. The site includes cave cells (which were used as burial sites once the temple was abandoned in the 4th century), a series of brick buildings, and small stupas. It is similar in design to other Buddhist temples built in Gandhara.
The Zurmala Tower is one of the oldest surviving buildings in Uzbekistan, dating from the 1st to 2nd centuries AD. Its brick structure is 16m high and is the only remaining part of a vast Buddhist stupa which would have been originally clad in stone and richly decorated.
Kampir Tepe was a substantial city built on the Amu Darya river by Alexander the Great. Known as Alexandria on the Oxus, the city had an important harbour with a lighthouse, as well as a citadel, temples, and a gateway that is a replica of one found in Pamphylia in Turkey. The site is still being excavated by archeologists but is open to the public.
Source 1: Centre of Hydrometeorological Service of Uzbekistan
Source 2: Pogoda.ru.net (mean temperatures/humidity/snow days 1981-2010, record low and record high temperatures),Deutscher Wetterdienst (sun 1961-1990)
Notable people of ancient Termez
Its most famous native son is Al-Tirmidhi, born in its suburb Bugh and buried 60 kilometers north of Termez, on the outskirts of Sherobod, Uzbekistan. He is one of the six canonical hadith collectors of Sunni Islam. He is locally known as Abu Isa At Termezi.
Hakim-at-Termizi, one of the famous Sufi theologians, is buried in old Termez which is in the suburbs of modern Termez. He is also known as Termez Ota (a patron saint of Termez).