Kentucky officially the Commonwealth of Kentucky, is a state in the Southeastern region of the United States, bordered by Illinois, Indiana, and Ohio to the north; West Virginia and Virginia to the east; Tennessee to the south; and Missouri to the west. The bluegrass region in the central part of the commonwealth contains the commonwealth's capital, Frankfort, as well as its two largest cities, Louisville and Lexington. Together they comprise more than 20% of the commonwealth's population. Kentucky is the 37th most extensive and the 26th most populous of the 50 United States.
Kentucky is situated in the Upland South. A significant portion of eastern Kentucky is part of Appalachia.
Kentucky borders seven states, from the Midwest and the Southeast. West Virginia lies to the northeast, Virginia to the east, Tennessee to the south, Missouri to the west, Illinois to the northwest, and Indiana and Ohio to the north. Only Missouri and Tennessee, both of which border eight states, touch more.
Kentucky's northern border is formed by the Ohio River and its western border by the Mississippi River; however, the official border is based on the courses of the rivers as they existed when Kentucky became a state in 1792. For instance, northbound travelers on U.S. 41 from Henderson, after crossing the Ohio River, will be in Kentucky for about two miles (3.2 km). Ellis Park, a thoroughbred racetrack, is located in this small piece of Kentucky. Waterworks Road is part of the only land border between Indiana and Kentucky.
Kentucky has a non-contiguous part known as Kentucky Bend, at the far west corner of the state. It exists as an exclave surrounded completely by Missouri and Tennessee, and is included in the boundaries of Fulton County. Road access to this small part of Kentucky on the Mississippi River (populated by 18 people as of 2010) requires a trip through Tennessee.
The epicenter of the 1811–12 New Madrid earthquakes was near this area, causing the Mississippi River to flow backwards in some places. Though the series of quakes changed the area geologically and affected the small number of inhabitants of the area at the time, the Kentucky Bend is the result of a surveying error, not the New Madrid earthquake.
Kentucky can be divided into five primary regions: the Cumberland Plateau in the east, which contains much of the historic coal mines; the north-central Bluegrass region, where the major cities and the capital are located; the south-central and western Pennyroyal Plateau (also known as the Pennyrile or Mississippi Plateau); the Western Coal Fields; and the far-west Jackson Purchase.
The Bluegrass region is commonly divided into two regions, the Inner Bluegrass encircling 90 miles (140 km) around Lexington, and the Outer Bluegrass that contains most of the northern portion of the state, above the Knobs. Much of the outer Bluegrass is in the Eden Shale Hills area, made up of short, steep, and very narrow hills.
Located within the southeastern interior portion of North America, Kentucky has a climate that is best described as a humid subtropical climate (Köppen: Cfa), only small higher areas of the southeast of the state has an oceanic climate (Cfb) influenced by the Appalachians. Temperatures in Kentucky usually range from daytime summer highs of 87 °F (31 °C) to the winter low of 23 °F (−5 °C). The average precipitation is 46 inches (1,200 mm) a year. Kentucky has four distinct seasons, with substantial variations in the severity of summer and winter. The highest recorded temperature was 114 °F (46 °C) at Greensburg on July 28, 1930, while the lowest recorded temperature was −37 °F (−38 °C) at Shelbyville on January 19, 1994. The state rarely experiences the extreme cold of far northern states, nor the high heat of the states in the Deep South. Temperatures seldom drop below 0 degrees or rise above 100 degrees. Rain and snowfall totals about 45 inches per year.
Climate varies markedly within the state. The northern parts tend to be about five degrees cooler than those in western parts of the state. Somerset in the south-central part receives ten more inches of rain per year than, for instance, Covington to the north. Average temperatures for the entire Commonwealth range from the low 30s in January to the high 70s in mid-July. The annual average temperature varies from 55 to 60 °F (13 to 16 °C): of 55 °F (13 °C) in the far north as an average annual temperature and of 60 °F (16 °C) in the extreme southwest.
In general, Kentucky has relatively hot, humid, rainy summers, and moderately cold and rainy winters. Mean maximum temperatures in July vary from 83 to 90 °F (28 to 32 °C); the mean minimum July temperatures are 61 to 69 °F (16 to 21 °C). In January the mean maximum temperatures range from 36 to 44 °F (2 to 7 °C); the mean minimum temperatures range from 19 to 26 °F (−7 to −3 °C). Temperature means vary with northern and far-eastern mountain-regions averaging five degrees cooler year-round, compared to the relatively warmer areas of the southern and western regions of the state. Precipitation also varies north to south with the north averaging of 38 to 40 inches (970 to 1,020 mm), and the south averaging of 50 inches (1,300 mm). Days per year below the freezing point vary from about sixty days in the southwest to more than a hundred days in the far-north and far-east.
