Roseville is the largest city in the Sacramento metropolitan area in Placer County, California, United States. The population of the town is estimated to be over 139,000. Interstate 80 runs through Roseville and State Route 65 passes through most of the city's northern side. The total area of this town is 42,26 square miles. Roseville has a Mediterranean hot-summer climate characterized by cold, humid, typically snowless winters, and long, dry summers.