🇲🇳Mongolia

Mongolia extends 41°35′–52°09′N as a vast (approximately 1,564,116 km²) doubly-landlocked Central Asian nation bordering Russia to the north and China to the south, holding the distinction of the world's most sparsely populated sovereign state with one of the most extreme continental climates on Earth — Ulaanbaatar stands as the world's coldest national capital.

The topography encompasses the Altai Mountains in the west with Khüiten Peak at 4,374 m (the country's highest point on the Russian-Chinese border, supporting substantial glaciation), the Khangai Mountains in the centre, the Khentii Mountains in the northeast forming the source of the Onon and Kherlen rivers, the immense Gobi Desert sprawling across the south, and vast central steppe.

This extraordinary geography produces an exceptional climate spectrum — humid continental (Dwb) in the wetter north, subarctic (Dwc) at higher elevations and forested taiga zones, cold semi-arid (BSk) and cold desert (BWk) across the steppe and Gobi covering roughly 75% of the country, and alpine tundra (ET) on the high Altai with the only Central Asian glaciers outside the Tian Shan and Pamir ranges.

Ulaanbaatar at 1,310 m averages −20°C in January and 18°C in July with only 290 mm annual rainfall — one of the world's coldest national capitals, experiencing diurnal winter temperature swings exceeding 30°C. Mörön in the north records −24°C in January and 17°C in July with 230 mm. Choibalsan in the east registers −22°C in January and 21°C in July with 230 mm. Khovd in the west averages −24°C in January and 19°C in July with 130 mm.

Dalanzadgad on the Gobi margin records −15°C in January and 22°C in July with 130 mm. Sainshand in the deep Gobi averages −16°C in January and 24°C in July with only 90 mm. Khüiten Peak averages −20°C with permanent ice. The all-time temperature range spans approximately −55.3°C at Tuvshruulekh in December 1959 to 44.0°C at Erdenedalai in July 1999.

Major events include the severe 1999–2002 dzud — a multi-year compound disaster of drought and extreme winter killing tens of millions of livestock and severe nomadic livelihoods — the severe 2009–10 dzud, the severe February 2018 cold-snap, the severe 2023–24 dzud (the worst on record, killing over 7 million livestock), recurrent severe steppe-fires and Gobi dust storms transported as far as Korea and Japan, and accelerating Altai glacier retreat with approximately 30% area loss since 1990.

Our archive covers 1 Mongolian cities with daily ERA5 reanalysis data going back to 1940. The warmest July averages occur in Ulan Bator, around 22.8°C, while Ulan Bator records the coldest January nights near −27.5°C. Comparing the last decade against the 1940–1970 baseline, mean temperatures across these cities have risen by about 1.5°C.