Connecticut is bordered on the south by
Long Island Sound, on the west by
New York, on the north by
Massachusetts, and on the east by
Rhode Island. The state capital and fourth largest city is
Hartford, and other major cities and towns (by population) include
Bristol. Connecticut is slightly larger than the country of
Montenegro. There are 169
incorporated towns in Connecticut.
The highest peak in Connecticut is
Bear Mountain in
Salisbury in the northwest corner of the state. The highest point is just east of where Connecticut,
Massachusetts, and New York meet (42° 3' N; 73° 29' W), on the southern slope of
Mount Frissell, whose peak lies nearby in Massachusetts.
 At the opposite extreme, many of the coastal towns have areas that are less than 20 feet (6 m) above sea level.
Connecticut has a long maritime history and a reputation based on that history—yet the state has no direct oceanfront (technically speaking). The coast of Connecticut sits on
Long Island Sound, which is an
estuary. The state's access to the open Atlantic Ocean is both to the west (toward New York City) and to the east (toward the "race" near Rhode Island). This situation provides many safe harbors from ocean storms, and many transatlantic ships seek anchor inside Long Island Sound when
tropical cyclones pass off the upper East Coast.
Connecticut River cuts through the center of the state, flowing into Long Island Sound. The most populous metropolitan region centered within the state lies in the
Connecticut River Valley. Despite Connecticut's relatively small size, it features wide regional variations in its landscape; for example, in the northwestern
Litchfield Hills, it features rolling mountains and horse farms, whereas in areas to the east of New Haven along the coast, the landscape features coastal
beaches, and large scale maritime activities.
Connecticut's rural areas and small towns in the northeast and northwest corners of the state contrast sharply with its industrial cities such as Stamford, Bridgeport, and New Haven, located along the coastal highways from the New York border to New London, then northward up the Connecticut River to Hartford. Many towns in northeastern and northwestern Connecticut center around a
green, such as the Litchfield Green, Lebanon Green (the largest in the state), and Wethersfield Green (the oldest in the state). Near the green typically stand historical visual symbols of
New England towns, such as a white
colonial meeting house, a colonial
colonial houses, and so on, establishing a scenic historical appearance maintained for both
historic preservation and tourism. Many of the areas in southern and coastal Connecticut have been built up and rebuilt over the years, and look less visually like traditional New England.
The northern boundary of the state with Massachusetts is marked by the Southwick Jog or Granby Notch, an approximately 2.5 miles (4.0 km) square detour into Connecticut. The origin of this anomaly is clearly established in a long line of disputes and temporary agreements which were finally concluded in 1804, when southern
Southwick's residents sought to leave Massachusetts, and the town was split in half.
The southwestern border of Connecticut where it abuts New York State is marked by a
Fairfield County, containing the towns of
Darien, and parts of
Wilton. This irregularity in the boundary is the result of
territorial disputes in the late 17th century, culminating with New York giving up its claim to the area, whose residents considered themselves part of Connecticut, in exchange for an equivalent area extending northwards from
Ridgefield to the Massachusetts border, as well as undisputed claim to
Rye, New York.
Areas maintained by the
National Park Service include
Appalachian National Scenic Trail,
Quinebaug and Shetucket Rivers Valley National Heritage Corridor, and
Weir Farm National Historic Site.
Köppen climate types in Connecticut
Much of Connecticut has a
humid continental climate, with cold winters with moderate snowfall and mild, humid summers. Coastal Connecticut has a milder
Temperate climate (called humid subtropical in some climate classifications) climate with hot, humid summers and warmer winters with a mix of rain and infrequent snow. Most of Connecticut sees a fairly even precipitation pattern with rainfall/snowfall spread throughout the 12 months. Connecticut averages 56% of possible sunshine, averaging 2,400 hours of
Early spring (April) can range from slightly cool to warm, while mid and late spring (late April/May) is warm. By June, the building
Bermuda High creates a southerly flow of warm and humid tropical air, bringing hot weather conditions throughout the state, with average highs in New London of 81 °F (27 °C) and 85 °F (29 °C) in Windsor Locks at the peak of summer in late July. Although summers are sunny in Connecticut, quick moving summer thunderstorms can bring brief downpours with thunder and lightning. Occasionally these thunderstorms can be severe, and the state usually averages one tornado per year.
 During hurricane season, the remains of tropical cyclones occasionally affect the region, though a direct hit is rare.
Fall type weather (cooler days and nights, fewer air masses thundershowers) starts in October and normally lasts to the first days of December. Daily high temperatures in October and November range from the 50's to 60's F with nights in the 40's and upper 30's F (November). Colorful foliage begins across northern parts of the state in late September and moves south and east reaching southeast Connecticut by early November. Far southern and coastal areas however have more oak and hickory trees (and fewer maples), and are often less colorful than areas to the north. By early December average overnight lows are below freezing across the entire state.
Winters (December through mid March) are generally cold from south to north in Connecticut. The coldest month (January) has average high temperatures ranging from 38 °F (3 °C) in the coastal lowlands to 33 °F (1 °C) in the inland and northern portions on the state. The average yearly snowfall ranges from about 60 inches (1,500 mm) in the higher elevations of the northern portion of the state to only 20–25 inches (510–640 mm) along the southeast coast of Connecticut (Branford to Groton). Generally, any locale north or west of
Interstate 84 receives the most snow, during a storm, and throughout the season. Most of Connecticut has less than 60 days of snow cover. Snow usually falls from late November to late March in the northern part of the state, and from early December to mid March in the southern and coastal parts of the state.
Connecticut's warmest temperature is 106 °F (41 °C) which occurred in
Danbury on July 15, 1995; the coldest temperature is −32 °F (−36 °C) which occurred in the Northwest Hills
Falls Village on February 16, 1943, and
Coventry on January 22, 1961.
|Monthly Normal High and Low Temperatures for Various Connecticut Cities
Forests consist of a mix of
Northeastern coastal forests of Oak in southern areas of the state, to the upland
New England-Acadian forests in the northwestern parts of the state. Mountain Laurel (
Kalmia latifolia) is the state flower, and is native to low ridges in several parts of Connecticut. Rosebay Rhododendron (
Rhododendron maximum) is also native to eastern uplands of Connecticut and
Pachaug State Forest is home to the Rhododendron Sanctuary Trail. Atlantic white cedar (
Chamaecyparis thyoides), is found in wetlands in the southern parts of the state. Connecticut has one native cactus (
Opuntia humifusa), found in sandy coastal areas and low hillsides. Several types of beach grasses and wildflowers are also native to Connecticut.
 Connecticut spans
USDA Plant Hardiness Zones 5b to 7a. Coastal Connecticut is the broad transition zone where more southern and subtropical plants are cultivated. In some coastal communities,
Magnolia grandiflora (southern magnolia),
Crape Myrtles, scrub palms (
Sabal minor), and other broadleaved evergreens are cultivated in small numbers.