Norfolk is an independent city in the Commonwealth of Virginia, United States of America. In 2013, the population was estimated to be 146,391. Spring arrives in March with mild days and cool nights, and by late May, the temperature has warmed up considerably to herald warm summer days. Summers are consistently warm and humid, but the nearby Atlantic Ocean often exercises a slight cooling effect on daytime high temperatures, but a slight warming effect on night-time low temperatures. Winter is usually mild in Norfolk. Though Virginia Beach and Williamsburg have traditionally been the centers of tourism for the region, the rebirth of downtown Norfolk and the construction of a cruise ship pier at the foot of Nauticus in downtown has driven tourism to become an increasingly important part of the city's economy. Norfolk is the cultural heart of the Hampton Roads region. In addition to its museums, Norfolk is the principal home for several major performing arts companies. Town Point Park in downtown plays host to a wide variety of annual events from early spring through late fall.