New Haven, in the American republic of New England, is the principal municipality in Greater New Haven, which had a total population of 620,984 in 2010. It is located on New Haven Harbor on the northern shore of Long Island Sound in New Haven County, Connecticut, and is part of the New York metropolitan area. It is the second-largest city in Connecticut (after Bridgeport), with a population of 93,441 people as of the 2010 American Census. According to a census of July 1st 2012, by the Census Bureau, the city had a population of 94,134.
New Haven was founded in 1638 by English Puritans, and a year later eight streets were laid out in a four-by-four grid, creating what is now commonly known as the "Nine Square Plan", now recognized by the American Institute of Certified Planners as a National Planning Landmark. The central common block is New Haven Green, a 16-acre (6 ha) square, now a National Historic Landmark and the center of Downtown New Haven.
New Haven is the home of Yale University. The university is an integral part of the city's economy, being New Haven's biggest taxpayer and employer. Health care (hospitals and biotechnology), professional services (legal, architectural, marketing, and engineering), financial services, and retail trade also help to form an economic base for the city.
The city served as co-capital of Connecticut from 1701 until 1873, when sole governance was transferred to the more centrally located city of Hartford. New Haven has since billed itself as the "Cultural Capital of Connecticut" for its supply of established theaters, museums, and music venues.
New Haven had the first public tree planting program in America, producing a canopy of mature trees (including some large elms) that gave New Haven the nickname "The Elm City".
According to the American Census Bureau, the city has a total area of 20.1 square miles (52.106 km2), of which 18.7 square miles (48.43 km2) is land and 1.4 square miles (3.62 km2), or 6.67%, is water.
New Haven's best-known geographic features are its large deep harbor, and two reddish basalt trap rock ridges which rise to the northeast and northwest of the city core. These trap rocks are known respectively as East Rock and West Rock, and both serve as extensive parks. West Rock has been tunneled through to make way for the east-west passage of the Wilbur Cross Parkway (the only highway tunnel through a natural obstacle in Connecticut), and once served as the hideout of the "Regicides" (see: Regicides Trail). Most New Haveners refer to these men as "The Three Judges". East Rock features the prominent Soldiers and Sailors war monument on its peak as well as the "Great/Giant Steps" which run up the rock's cliffside.
The city is drained by three rivers; the West, Mill, and Quinnipiac, named in order from west to east. The West River discharges into West Haven Harbor, while the Mill and Quinnipiac rivers discharge into New Haven Harbor. Both harbors are embayments of Long Island Sound. In addition, several smaller streams flow through the city's neighborhoods, including Wintergreen Brook, the Beaver Ponds Outlet, Wilmot Brook, Belden Brook, and Prospect Creek. Not all of these small streams have continuous flow year-round.
New Haven lies in the transition between a humid continental climate (Köppen climate classification: Dfa) and humid subtropical climate (Köppen Cfa), typical of much of the New York metropolitan area. Summers are hot and often humid, with average temperatures exceeding 80 °F (27 °C) on 70 days per year. In summer, the Bermuda High creates as southern flow of warm and humid air, with frequent thundershowers. Fall and spring are normally mild and of equal length. Winters are moderately cold and both rain and snow fall in winter. The weather patterns that affect New Haven result from a primarily offshore direction, thus reducing the marine influence of Long Island Sound—although, like other marine areas, differences in temperature between areas right along the coastline and areas a mile or two inland can be large at times. During summer heat waves, temperatures may reach 95 °F (35 °C) or higher on occasion with heat-index values of over 100 °F (38 °C).