Ulaanbator - Geography and Climate

Geography and Climate

Ulan Bator is located at about 1,350 metres (4,430 ft) above mean sea level, slightly east of the centre of Mongolia on the Tuul River, a subtributary of the Selenge, in a valley at the foot of the mountain Bogd Khan Uul. Bogd Khan Uul is a broad, heavily forested mountain rising 2,250 metres (7,380 ft) to the south of Ulan Bator. It forms the boundary between the steppe zone to the south and the forest-steppe zone to the north. It is also one of the oldest reserves in the world, being protected by law since the 18th century. The forests of the mountains surrounding Ulan Bator are composed of evergreen pines, deciduous larches and birches while the riverine forest of the Tuul River is composed of broad-leaved, deciduous poplars, elms and willows.

Owing to its high elevation, its relatively high latitude, its location hundreds of kilometres from any coast, and the effects of the Siberian anticyclone, Ulan Bator is the coldest national capital in the world, with a monsoon-influenced, cold semi-arid climate (Köppen BSk, USDA Plant Hardiness Zone 3b) that closely borders a subarctic climate. The city features brief, warm summers and long, bitterly cold and dry winters. The coldest January temperatures, usually at the time just before sunrise, are between −36 °C (−33 °F) and −40 °C (−40 °F) with no wind, due to temperature inversion. Most of the annual precipitation of 216 millimetres (8.50 in) falls from June to September. The highest recorded precipitation in the city was 659 mm (26 in) at the Khureltogoot Astronomical Observatory on Mount Bogd Khan Uul. Ulan Bator has an average annual temperature of −2.4 °C (27.7 °F). The city lies in the zone of discontinuous permafrost, which means that building is difficult in sheltered aspects that preclude thawing in the summer, but easier on more exposed ones where soils fully thaw. Suburban residents live in traditional yurts that do not protrude into the soil. Extreme temperatures in the city range from −49 °C (−56 °F) to 38.6 °C (101.5 °F).