Alberta is a province in Canada. It is a part of Western Canada and is one of the three prairie provinces. Alberta is bordered by British Columbia to its west, Saskatchewan to its east, the Northwest Territories to its north, and the U.S. state of Montana to its south. Alberta and Saskatchewan are the only two landlocked Canadian provinces. The eastern part of the province is occupied by the Great Plains, while the western part borders the Rocky Mountains. The province has a predominantly continental climate, but seasonal temperatures tend to swing rapidly because it is so arid. Those swings are less pronounced in western Alberta because of its occasional Chinook winds. Alberta is the fourth largest province by area, at 661,848 square kilometres, and the fourth most populous, with 4,262,635 residents. Alberta's capital is Edmonton; its largest city is Calgary. The two cities are Alberta's largest census metropolitan areas. More than half of Albertans live in Edmonton or Calgary, which encourages a continuing rivalry between the two cities. English is the province's official language. In 2016, 76.0% of Albertans were anglophone, 1.8% were francophone and 22.2% were allophone.