Jammu is the largest city in the Jammu Division and the winter capital of Jammu and Kashmir. It is situated on the banks of Tawi river.
Jammu is located at 32.73°N 74.87°E. It has an average elevation of 327 m (1,073 ft). Jammu city lies at uneven ridges of low heights at the Shivalik hills. It is surrounded by Shivalik range to the north, east and southeast while the Trikuta Range surrounds it in the north-west. It is approximately 600 kilometres (370 mi) from the national capital, New Delhi.
The city spreads around the Tawi river with the old city overlooking it from the north (right bank) while the new neighbourhoods spread around the southern side (left bank) of river. There are four bridges on the river. The fifth bridge on the Tawi river is under construction. The city is built on a series of ridges.The name Jammu is derived from its ruler who founded it. Raja Jambulochan founded this city and named it Jambupora which later changed to Jammu. Many historians and locals believe that Jammu was founded by Raja Jambu Lochan in the 14th century BC. During one of his hunting campaigns, he reached the Tawi River where he saw a goat and a lion drinking water at the same place. Having satisfied their thirst, the animals went their own ways. The Raja was amazed, abandoned the idea of hunting and returned to his companions. Recounting what he had seen, he exclaimed that this place, where a lion and a lamb could drink water side by side, was a place of peace and tranquility. The Raja commanded that a palace be built at this place and a city was founded around it. This city became known as Jambu-Nagar, which then later changed into Jammu.
Jammu has historically been the capital of Jammu Province and the winter capital of the erstwhile Jammu and Kashmir princely state (1846–1952).Jambu Lochan was the brother of Raja Bahu Lochan who constructed a fort, Bahu Fort, on the bank of river Tawi.The city name figures in the ancient book Mahabharata. Excavation near Akhnoor, 32 kilometres (20 mi) from Jammu city, provides evidence that Jammu was once part of the Harappan civilization. Remains from the Maurya, Kushan, Kushanshahs and Gupta periods have also been found in Jammu. After 480 CE, the area was dominated by the Hephthalites and ruled from Kapisa and Kabul. They were succeeded by the Kushano-Hephthalite dynasty from 565 to 670 CE, then by the Shahi from 670 CE to the early 11th century, when the Shahi were destroyed by the Ghaznavids. Jammu is also mentioned in accounts of the campaigns of Timur. The area witnessed changes of control following invasions by Mughals and Sikhs, before finally falling under the control of the British. The Dev Dynasty ruled it for about 984 years from 840 CE to 1816 CE. The city remained in scientific isolation and lagged behind other Indian cities. Then came the Dogra Rule that revived its ancient glory by building great temples, renovated old shrines, built educational institutes and many more. A 43 km long railway line connecting Jammu with Sialkot was laid in 1897 but it was abandoned after the Partition of India as the railway link to Sialkot was broken. Jammu had no rail services until 1971, when the Indian Railways laid the Pathankot - Jammu Tawi Broad Gauge line. The new Jammu Tawi station was opened in 1975. In 2000, much of the old railway station was demolished to make way for an art centre. After partition of India, Jammu continued to be the winter capital of state.
Jammu, like the rest of north-western India, features a humid subtropical climate with extreme summer highs reaching 46 °C (115 °F), and temperatures in the winter months occasionally falling below freezing. June is the hottest month with average highs of 40.6 °C (105.1 °F), while January is the coldest month with average lows reaching 7 °C (45 °F). Average yearly precipitation is about 42 inches (1,100 mm) with the bulk of the rainfall in the months from June to September, although the winters can also be rather wet. In winter dense smog causes much inconvenience and temperature even drops to 2 °C (36 °F). In summer, particularly in May and June, extremely intense sunlight or hot winds can raise the mercury to 46 °C (115 °F). Following the hot season, the monsoon lashes the city with heavy downpours along with thunderstorms: rainfall may total up to 669 mm (26.3 in) in the wettest months.