Banja Luka or Banjaluka, in cyrillic letters spelt Бања Лука, is the capital and the largest city in the Republika Srpska entity and the second largest city in Bosnia and Herzegovina after Sarajevo. It has traditionally been the centre of the Bosanska Krajina, a region located in the northwest of the country on the Vrbas river.
Banja Luka covers some 96.2 kilometres (37.1 miles) of land in northwestern Bosnia on the Vrbas River. Banja Luka's downtown is at 163 metres above sea level, surrounded by hills.
The source of the Vrbas River is about 90 km (56 ml) to the south. The tributary rivers of Suturlija, Crkvena, and Vrbanja flow into the Vrbas at Banja Luka. Banja Luka also has a number of springs close by.
The area immediately around Banja Luka is woodland, although there are mountains a little further from the city. The city itself is built in the Banja Luka valley, which is located at the transition between high and low mountain areas. The most notable of the mountains are Manjača (1214 meters), Čemernica (1,338 meters), and Tisovac. These are all part of the Dinaric Alps mountain range.
Banja Luka has a continental climate, with harsh winters and warm summers. The warmest month of the year is July, with an average temperature of 21.3 °C (70 °F). The coldest month of the year is January, when temperatures average near freezing at 0.8 °C (33 °F).
Annual precipitation for Banja Luka is about 988 mm. Banja Luka has an average of 143 rainy days a year. Due to the city's high latitude, it snows in Banja Luka almost every year as well. Strong winds come from the north and northeast.