Mongolia has an extreme continental climate with very cold winters and hot summers. Mongolia lies at the heart of continental Asia, far from ocean and surrounded by high mountains that contribute to it’s dry climate. Mongolia is a remarkably sunny country, enjoying 257 sunny days a year, often with clear cloudless skies. So Mongolia is known as the “Land of Blue Skies”.
Winter is the coldest season; lasting from November to March. Winter average temperature over most of the country is below freezing from November through March. January is the coldest month of the year, with the average temperature at -35°C in the Mountain and -25°C in the Gobi. All rivers and freshwater lakes freeze over in the winter, and smaller streams commonly freeze to the bottom.
Summer continues from June to September. Summer extremes reach as high as 38°C in the southern Gobi region and 33° C in Ulaanbaatar. July is the warmest month, often plus 25°C. And with average temperature between 15 and 25°C in the mountain and in the Gobi 25-38°C.
Precipitation is highest in the mountain, which averages 20 to 35 centimeters per year, and lowest in the Gobi, which receives 10 to 20 centimeters. The extreme south is the Gobi, some regions of which receive no precipitation at all in most years. The name Gobi is a Mongol meaning desert, depression, salt marsh, or steppe, but which usually refers to a category of arid rangeland with insufficient vegetation to support marmots but with enough to support camels. Ulaanbaatar lies at 1,351 meters above sea level in the valley of the Tuul Gol, a river. Located in the relatively well-watered north, it receives an annual average of 31 centimeters of precipitation, almost all of which falls in July and in August.