Fort Worth is located in northern Texas, on the Clear Fork of the Trinity River. Fort Worth has a continental climate, with hot summers and moderately cold winters. The city is a major road, rail, and air junction, as well as a manufacturing and processing center with a diversified economy. Its economy relied on military bases, particularly Carswell Air Force Base. Although aerospace and automobiles remain an important part of its economy, Fort Worth has become more integrated into the economy of the Dallas-Fort Worth Consolidated Metropolitan Statistical Area, also known as the Metroplex. A 2006 real estate survey has estimated the population of Fort Worth, Texas at 653,320.