Located close to the confluence of the Mississippi and Missouri rivers, St. Louis is the second-largest city in Missouri, USA. The bi-state metropolitan area, including Illinois, was projected to have a population of approximately 2.8 million in 2020, making it the largest in Missouri and the second-largest in Illinois. The city itself had a population of 301,578.
In the metropolitan area, St. Louis currently houses 11% of the population in the twenty-first century. Although there was a slight increase in the early 2000s, the city saw a population decline between 2000 and 2010. The city still attracts the largest Bosnian community outside of Bosnia and Herzegovina, as well as Latin Americans primarily from Mexico and Vietnamese immigrants. The St. Louis metropolitan area, located to the south, may experience a hot-summer humid continental climate (Dfa), indicating the influence of the urban heat island in the region. St. Louis' urban area has a humid subtropical climate with hot, humid summers and cold winters that can vary from cool to freezing, influenced by both the hot, humid tropical air from the Gulf of Mexico and the cold Northern air.