Washington, D.C. is located in the Mid-Atlantic region of the United States at 38°53′42″N77°02′11″W / 38.89500°N 77.03639°W , the coordinates of the Zero Milestone, on The Ellipse. According to the United States Census Bureau, the city has a geographical area of 68.3 square miles (176.9 km2), 61.4 square miles (159.0 km2) of which is land, and the remaining 6.9 square miles (17.9 km2) (10.16%) of which is water. The Anacostia River and the smaller Rock Creek flow into the Potomac River in Washington.
Washington, D.C. is surrounded by Northern Virginia on its southwest side and Maryland on its southeast, northeast, and northwest sides; it interrupts those states' shared border, which is the south shore of the Potomac River both upstream and downstream from the city. The portion of the Potomac River that passes Washington, D.C. is virtually entirely within the city's border, as Washington, D.C. extends to the south bank. The city contains the remaining federal district, which was formerly part of those two adjacent states before they respectively ceded it for the national capital in the 1790s. The land ceded from Virginia was returned by Congress in 1847, so what remains of the modern District was all once part of Maryland.
The topography of Washington, D.C. is highly similar to the physical geography of much of Maryland. The city has three significant natural flowing bodies of water: the Potomac River and two tributaries, the Anacostia River and Rock Creek. The confluence of the Potomac and Anacostia forms the historic peninsula known as Arsenal Point. The District also includes the Washington Channel, which flows into the junction of the Anacostia and Potomac rivers. There are also three artificial reservoirs: Dalecarlia Reservoir, which crosses over the northwest border of the District from Maryland, McMillan Reservoir near Howard University, and Georgetown Reservoir upstream of Georgetown. A fourth, minor reservoir is at Fort Reno in Tenleytown.
Washington, D.C. is situated in a topographic bowl. The bottom of the bowl, where the White House and United States Capitol are located, is in the floodplain of the junction of the Anacostia and Potomac Rivers. Extending out from the floodplain is a series of rising river terraces. These high ridges nearly surround the city. The highest of these terraces is 200 feet above sea level and is fronted by an escarpment that is very prominent along the east side of the Anacostia River. Steep-sided ravines and small streams cut through the upper terrace east of the Anacostia River at frequent intervals. Examples of these stream valleys can be found at Forts Dupont and Stanton. [1]
Washington, D.C. is located on the fall line, the border of two considerably different geological terrains or provinces; the hard rock of the Piedmont Plateau to the north and west and the soft sediments of the Atlantic Coastal Plain to the east. The Piedmont Plateau is located north and west of the city. Deeply cut valleys and prominent ridges characterize this area. [1]
The highest point in Washington, D.C. is 410 feet (125 m) above sea level at Reno Reservoir in Tenleytown. [2] The lowest point is sea level, which occurs along all of the Anacostia shore and all of the Potomac shore except the uppermost 100 meters (the Little Falls-Chain Bridge area). The sea level in the Tidal Basin rose eleven feet during Hurricane Isabel on September 18, 2003. The geographic center of Washington, D.C. is on the site of the Organization of American States headquarters. [3] The U.S. Capitol marks the intersection of the city's four administrative quadrants.
Other prominent geographical features of Washington, D.C., include Theodore Roosevelt Island, Columbia Island, the Three Sisters, and Hains Point.
Some areas, especially around the National Mall and parts of Foggy Bottom, were marshes or parts of the river that have been filled in.
During the 18th century, significant portions of the region were forested, with species including rabbits, turkey, pheasants, woodcocks, turtles, and quail, as well as numerous bird species including mockingbirds, bluebirds, hummingbirds, and orioles. Other indigenous species include black snake, garter snake, rattlesnake, copperhead, bullfrog and other types of frogs, ground squirrels, flying squirrels, skunks, opossums, raccoons, foxes, beavers, deer, wolves, and bears. Snipes and various types of ducks inhabited swampy areas, as well as soruses. [4]
Native tree species include willow, birch, cedar, and oak. Other plant species found along the Potomac during the early 19th century include yellow jessamine, prickly pear cactus, white horehound, sweet fennel, wild cherries, and wild strawberries. [4] The large percentage of parkland contributes to a high urban tree canopy coverage of 35%. [5]
In 1965, President Lyndon Johnson called the Potomac River a "national disgrace" and used the river to illustrate the need for the Clean Water Restoration Act of 1966. [6] The river is now home to a vibrant warm-water fishery and naturally reproducing bald eagles have returned to its banks. [7] Despite its intensely urbanized landscape, the District of Columbia is a center for research on urban wildlife management, invasive species management, urban stream restoration, and the aquatic ecology of urban streams. [8] The National Park Service's Center For Urban Ecology is a regional source of expertise and applied science for the region. [9]
Earthquake activity in the District of Columbia is low. No earthquakes have been centered within the District, nor are there any faults. However, it has felt earthquakes centered in Virginia, Maryland, and other surrounding states and large earthquakes in Canada and New England.
The District felt the 1811–1812 New Madrid earthquakes, and according to old records, residents were "badly frightened". In March 1828, President John Quincy Adams felt a "violent" earthquake in the White House and wrote it in his journal. The 1886 Charleston earthquake (magnitude 6.6 to 7.3) was felt in DC. The strongest earthquake in Virginia happened in 1897 and was felt in the District. An earthquake in 1925 in Canada, estimated about magnitude 7, was felt over 2 million square miles (5.18 million km2). Another 6.2 earthquake in 1935 caused damage in New York and shook residents from Maine to Wisconsin. [10]
The 2011 Virginia earthquake was felt in Washington and caused damage to landmarks and monuments such as the Washington Monument and the Washington National Cathedral.
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Washington, D.C., is located in the humid subtropical climate zone (Köppen climate classification: Cfa), exhibiting four distinct seasons. [11] Its climate is typical of the mid-Atlantic states. The District is located in USDA plant hardiness zone 8a near downtown, and zone 7b elsewhere in the city, indicating a temperate climate. [12] As implied in the previous sentence, the downtown area exhibits an urban heat island (UHI) build-up that can especially exacerbate the sultriness of summer nights.
The highest recorded temperature was 106 °F (41 °C) on July 20, 1930, and August 6, 1918, while the lowest recorded temperature was −15 °F (−26 °C) on February 11, 1899, right before the Great Blizzard of 1899. [19] [22] The extreme low daily high temperature was 4 °F (−16 °C), occurring one day before the all-time minimum, while the extreme high daily low temperature was 84 °F (29 °C) on July 23–24, 2011 and July 16, 1983. [13] Monthly mean temperatures have ranged from 23.7 °F (−4.6 °C) in January 1918 to 84.5 °F (29.2 °C) in July 2011, while the corresponding range for the annual mean is 52.2 °F (11.2 °C) in 1904 to 61.5 °F (16.4 °C) in 2012. [lower-alpha 1]
Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
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Record high °F (°C) | 80 (27) | 84 (29) | 93 (34) | 95 (35) | 99 (37) | 104 (40) | 106 (41) | 106 (41) | 104 (40) | 98 (37) | 86 (30) | 79 (26) | 106 (41) |
Mean maximum °F (°C) | 66.7 (19.3) | 68.1 (20.1) | 77.3 (25.2) | 86.4 (30.2) | 91.0 (32.8) | 95.7 (35.4) | 98.1 (36.7) | 96.5 (35.8) | 91.9 (33.3) | 84.5 (29.2) | 74.8 (23.8) | 67.1 (19.5) | 99.1 (37.3) |
Mean daily maximum °F (°C) | 44.8 (7.1) | 48.3 (9.1) | 56.5 (13.6) | 68.0 (20.0) | 76.5 (24.7) | 85.1 (29.5) | 89.6 (32.0) | 87.8 (31.0) | 80.7 (27.1) | 69.4 (20.8) | 58.2 (14.6) | 48.8 (9.3) | 67.8 (19.9) |
Daily mean °F (°C) | 37.5 (3.1) | 40.0 (4.4) | 47.6 (8.7) | 58.2 (14.6) | 67.2 (19.6) | 76.3 (24.6) | 81.0 (27.2) | 79.4 (26.3) | 72.4 (22.4) | 60.8 (16.0) | 49.9 (9.9) | 41.7 (5.4) | 59.3 (15.2) |
Mean daily minimum °F (°C) | 30.1 (−1.1) | 31.8 (−0.1) | 38.6 (3.7) | 48.4 (9.1) | 58.0 (14.4) | 67.5 (19.7) | 72.4 (22.4) | 71.0 (21.7) | 64.1 (17.8) | 52.2 (11.2) | 41.6 (5.3) | 34.5 (1.4) | 50.9 (10.5) |
Mean minimum °F (°C) | 14.3 (−9.8) | 16.9 (−8.4) | 23.4 (−4.8) | 34.9 (1.6) | 45.5 (7.5) | 55.7 (13.2) | 63.8 (17.7) | 62.1 (16.7) | 51.3 (10.7) | 38.7 (3.7) | 28.8 (−1.8) | 21.3 (−5.9) | 12.3 (−10.9) |
Record low °F (°C) | −14 (−26) | −15 (−26) | 4 (−16) | 15 (−9) | 33 (1) | 43 (6) | 52 (11) | 49 (9) | 36 (2) | 26 (−3) | 11 (−12) | −13 (−25) | −15 (−26) |
Average precipitation inches (mm) | 2.86 (73) | 2.62 (67) | 3.50 (89) | 3.21 (82) | 3.94 (100) | 4.20 (107) | 4.33 (110) | 3.25 (83) | 3.93 (100) | 3.66 (93) | 2.91 (74) | 3.41 (87) | 41.82 (1,062) |
Average snowfall inches (cm) | 4.9 (12) | 5.0 (13) | 2.0 (5.1) | 0.0 (0.0) | 0.0 (0.0) | 0.0 (0.0) | 0.0 (0.0) | 0.0 (0.0) | 0.0 (0.0) | 0.0 (0.0) | 0.1 (0.25) | 1.7 (4.3) | 13.7 (35) |
Average precipitation days (≥ 0.01 in) | 9.7 | 9.3 | 11.0 | 10.8 | 11.6 | 10.6 | 10.5 | 8.7 | 8.7 | 8.3 | 8.4 | 10.1 | 117.7 |
Average snowy days (≥ 0.1 in) | 2.8 | 2.7 | 1.1 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.1 | 1.3 | 8.0 |
Average relative humidity (%) | 62.1 | 60.5 | 58.6 | 58.0 | 64.5 | 65.8 | 66.9 | 69.3 | 69.7 | 67.4 | 64.7 | 64.1 | 64.3 |
Average dew point °F (°C) | 21.7 (−5.7) | 23.5 (−4.7) | 31.3 (−0.4) | 39.7 (4.3) | 52.3 (11.3) | 61.5 (16.4) | 66.0 (18.9) | 65.8 (18.8) | 59.5 (15.3) | 47.5 (8.6) | 37.0 (2.8) | 27.1 (−2.7) | 44.4 (6.9) |
Mean monthly sunshine hours | 144.6 | 151.8 | 204.0 | 228.2 | 260.5 | 283.2 | 280.5 | 263.1 | 225.0 | 203.6 | 150.2 | 133.0 | 2,527.7 |
Percent possible sunshine | 48 | 50 | 55 | 57 | 59 | 64 | 62 | 62 | 60 | 59 | 50 | 45 | 57 |
Average ultraviolet index | 2 | 3 | 5 | 7 | 8 | 9 | 9 | 8 | 7 | 4 | 3 | 2 | 6 |
Source 1: NOAA (relative humidity, dew point and sun 1961−1990) [13] [24] [25] [26] | |||||||||||||
Source 2: Weather Atlas (UV) [27] |
Climate data for Washington, D.C. (Reagan National, 1945-07-01–present) | |||||||||||||
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Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
Record high °F (°C) | 79 (26) | 82 (28) | 89 (32) | 95 (35) | 99 (37) | 104 (40) | 105 (41) | 105 (41) | 101 (38) | 98 (37) | 86 (30) | 79 (26) | 105 (41) |
Record low °F (°C) | −5 (−21) | 4 (−16) | 14 (−10) | 24 (−4) | 34 (1) | 47 (8) | 54 (12) | 49 (9) | 39 (4) | 29 (−2) | 16 (−9) | 3 (−16) | −5 (−21) |
Source: NOAA [13] |
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Washington, D.C. was created to serve as the national capital from its inception. The Residence Act of 1790 required that the capital's territory would be located along the Potomac River within an area that Maryland and Virginia would cede to the federal government. However, it permitted the nation's first president, George Washington, to select the territory's precise location. President Washington then chose for the territory a square whose sides were 10 miles (16 km) in length and whose corners were directly north, east, south, and west of its center. The area of the square contained the existing towns of Georgetown and Alexandria, as well as two small villages, Hamburgh in the Foggy Bottom area and Carrollsburg near the confluence of the Potomac and Anacostia rivers. [28] [29]
The Residence Act had granted the president the authority to locate the federal capital's territory only as far south and east as the mouth of the Anacostia River in Maryland. However, President Washington wanted to expand the territory's area southward so that its boundaries could encompass the town of Alexandria. In 1791, Congress amended the Residence Act to approve President Washington's selected site, which included the portion of the territory that Virginia would cede. [30]
The location of the capital had many natural advantages: the Potomac was navigable up to the territory, allowing for boat traffic; the established ports at Alexandria and Georgetown could provide an important economic base for a major city; and the territory's inland location was close to the Northwest Territory. [30] During 1791–1792, Andrew Ellicott and several assistants, including Benjamin Banneker, surveyed the boundary between the federal territory and the states of Virginia and Maryland, placing marker stones at every mile point. Many of the stones are still standing. [31]
A new federal city, named in 1791 as the City of Washington in the Territory of Columbia, was then laid out in a largely undeveloped area at the center of the 100 square-mile federal territory. This city, which Pierre (Peter) L'Enfant designed, was bounded to the north by Boundary Street (now Florida Avenue) at the base of the escarpment of the Atlantic Seaboard Fall Line, to the southeast by the Anacostia River, to the southwest by the Potomac River and to the west by Rock Creek. [32] [33] Although L'Enfant designed the city's original layout in 1791, surveyor Andrew Ellicott revised it in 1792 (see Streets and highways of Washington, D.C.). [32] The remainder of the territory was designated as Washington County (on the Maryland side of the Potomac) and Alexandria County (on the Virginia side).
The land from Virginia was eventually returned to the state in 1846, effective 1847. This land in Virginia makes up the modern area of Arlington County and the old part of Alexandria, Virginia, both of which are Washington, D.C. suburbs. Arlington National Cemetery and The Pentagon are both located in Arlington, though the Pentagon has a Washington DC mailing address. Between 1790 and 1846, Alexandria was referred to as Alexandria, D.C.
Georgetown was originally part of Maryland and was the only significant population in the area that would become part of Washington, D.C. when the federal city was first created but which remained an independent city then referred to as Georgetown, D.C., until 1871 when it was merged with Washington City and Washington County, completing the process of Washington and the District of Columbia occupying the same geographic borders.
The monumental core of the city includes the National Mall and many key federal buildings, monuments, and museums, including the Lincoln Memorial, Washington Monument, and the National Air and Space Museum. Its layout is based on that proposed by the McMillan Commission report in 1901.
To preserve the grandeur of the National Mall, the White House, the Capitol, and various other key locations, the entire city is subject to strict building height limits. This limitation was placed in effect just before the 20th century when government officials realized that structural steel "skyscrapers" could overwhelm the city. In 1899, Congress enacted a height limit for the District prohibiting private buildings from rising more than 130 feet. Contrary to popular belief, no law has ever restricted buildings to the height of the United States Capitol or Washington Monument. [34] [35]
A revised height law in 1910 did away with that fixed maximum. The newer legislation, still in effect today, states that no new building may be more than 20 feet taller than the width of the street in front of it. [36] The current law is codified as D.C. CODE ANN. § 6-601.05. Thus, Washington has a relatively modest skyline in comparison to the majority of American cities. However, the District is ringed by high-rise buildings in many nearby suburbs like Arlington, Silver Spring, and Bethesda.
Washington, D.C. is divided into eight wards and 37 Advisory Neighborhood Commissions (ANCs) within these wards. The total number of named neighborhoods is 127. The ANCs serve to advise the Washington, D.C. city council on neighborhood matters. The council is required by law to give their opinions great weight, though what that means is up to the Council to decide. Since 2000, the demographics of many neighborhoods have changed markedly.
The District of Columbia is bordered by various cities, towns, villages, and unincorporated CDPs in Maryland and Virginia. Following is a list of those adjacent communities.
In addition to the places named above, there are other small unincorporated parts of Prince George's County, Maryland, which also border Washington, D.C.
The Potomac River is a major river in the Mid-Atlantic region of the United States that flows from the Potomac Highlands in West Virginia to the Chesapeake Bay in Maryland. It is 405 miles (652 km) long, with a drainage area of 14,700 square miles (38,000 km2), and is the fourth-largest river along the East Coast of the United States. More than 6 million people live within its watershed.
Arlington County, or simply Arlington, is a county in the U.S. state of Virginia. The county is located in Northern Virginia on the southwestern bank of the Potomac River directly across from Washington, D.C., the national capital.
Washington, D.C., formally the District of Columbia and commonly known as Washington or D.C., is the capital city and federal district of the United States. The city is on the Potomac River, across from Virginia, and shares land borders with Maryland to its north and east. It was named for George Washington, the first president of the United States. The district is named for Columbia, the female personification of the nation.
Georgetown is a historic neighborhood and commercial district in Northwest Washington, D.C., situated along the Potomac River. Founded in 1751 as part of the colonial-era Province of Maryland, Georgetown predated the establishment of Washington, D.C. by 40 years. Georgetown was an independent municipality until 1871 when the United States Congress created a new consolidated government for the entire District of Columbia. A separate act, passed in 1895, repealed Georgetown's remaining local ordinances and renamed Georgetown's streets to conform with those in Washington, D.C.
The Potomac Heritage Trail, also known as the Potomac Heritage National Scenic Trail or the PHT, is a designated National Scenic Trail corridor spanning parts of the mid-Atlantic region of the United States that will connect various trails and historic sites in Virginia, Maryland, Pennsylvania, and the District of Columbia. The trail network includes 710 miles (1,140 km) of existing and planned sections, tracing the natural, historical, and cultural features of the Potomac River corridor, the upper Ohio River watershed in Pennsylvania and western Maryland, and a portion of the Rappahannock River watershed in Virginia. The trail is managed by the National Park Service and is one of three National Trails that are official NPS units.
Theodore Roosevelt Island is an 88.5-acre (358,000 m2) island and national memorial located in the Potomac River in Washington, D.C. During the Civil War, it was used as a training camp for the United States Colored Troops. The island was given to the federal government by the Theodore Roosevelt Association in memory of the 26th president, Theodore Roosevelt. Until then, the island had been known as My Lord's Island, Barbadoes Island, Mason's Island, Analostan Island, and Anacostine Island.
The Residence Act of 1790, officially titled An Act for establishing the temporary and permanent seat of the Government of the United States, is a United States federal statute adopted during the second session of the 1st United States Congress and signed into law by President George Washington on July 16, 1790. The Act provides for a national capital and permanent seat of government to be established at a site along the Potomac River and empowered President Washington to appoint commissioners to oversee the project. It also set a deadline of December 1800 for the capital to be ready, and designated Philadelphia as the nation's temporary capital while the new seat of government was being built. At the time, the federal government operated out of New York City.
The County of Washington was one of five original political entities within the District of Columbia, the capital of the United States. Formed by the Organic Act of 1801 from parts of Montgomery and Prince George's County, Maryland, Washington County referred to all of the District of Columbia "on the east side of the Potomac, together with the islands therein." The bed of the Potomac River was also considered to be part of Washington County.
The history of Washington, D.C., is tied to its role as the capital of the United States. The site of the District of Columbia along the Potomac River was first selected by President George Washington. The city came under attack during the War of 1812 in an episode known as the Burning of Washington. Upon the government's return to the capital, it had to manage the reconstruction of numerous public buildings, including the White House and the United States Capitol. The McMillan Plan of 1901 helped restore and beautify the downtown core area, including establishing the National Mall, along with numerous monuments and museums.
District of Columbia retrocession is the act of returning some or all of the land that had been ceded to the federal government of the United States for the purpose of creating its federal district for the new national capital, which was moved from Philadelphia to what was then called the City of Washington in 1800. The land was originally ceded to the federal government by Virginia and Maryland in 1790. After moving through various stages of federal and state approval, the Virginia portion was returned in March 1847.
Dalecarlia Reservoir is the primary storage basin for drinking water in Washington, D.C., and Arlington County, Virginia. The reservoir is fed by an underground aqueduct in turn fed by low dams which divert portions of the Potomac River near Great Falls and Little Falls. The reservoir is located between Spring Valley and the Palisades, two neighborhoods in Northwest Washington, D.C., and Brookmont, a neighborhood in Montgomery County, Maryland.
Streetcars in Washington, D.C. transported people across the city and region from 1862 until 1962.
South Capitol Street is a major street dividing the southeast and southwest quadrants of Washington, D.C., in the United States. It runs south from the United States Capitol to the D.C.–Maryland line, intersecting with Southern Avenue. After it enters Maryland, the street becomes Indian Head Highway at the Eastover Shopping Center, a terminal or transfer point of many bus routes.
Old Town Alexandria is one of the original settlements of the city of Alexandria, Virginia, and is located about a half hour by car from Washington, D.C., of which it used to make up the southern part. It was the oldest district of D.C. until it was ceded back to Virginia in 1846. Old Town is situated in the eastern and southeastern area of Alexandria along the Potomac River and is laid out on a grid plan of substantially square blocks.
The District of Columbia Organic Act of 1871 is an Act of Congress that repealed the individual charters of the cities of Washington and Georgetown and established a new territorial government for the whole District of Columbia. Though Congress repealed the territorial government in 1874, the legislation was the first to create a single municipal government for the federal district. Direct rule by Congress continued until the 1973 passage of the District of Columbia Home Rule Act, a century later.
The U.S. state of Maryland has a varied geography. It has an area of 12,406.68 square miles (32,133.2 km2) and is comparable in overall area with Belgium [11,787 square miles (30,530 km2)]. It is the 42nd largest and 9th smallest state and is closest in size to the state of Hawaii, the next smallest state. The next largest state, its neighbor West Virginia, is almost twice the size of Maryland. Maryland borders Pennsylvania to the north, Delaware to the northeast, the Atlantic Ocean to the east, and to the west and south by West Virginia and Virginia.
The Nacotchtank, also Anacostine, were an Algonquian Indigenous people of the Northeastern Woodlands.
The Alexandria Extension is a short rail line in Washington, D.C. and Prince George's County, Maryland. Its northern portion connects the Capital Subdivision to the RF&P Subdivision, allowing freight trains to avoid Downtown Washington. Its southern portion, the Shepherd Industrial Spur, extends south to Shepherds Landing, directly across the Potomac River from Alexandria, Virginia; service on this portion ended in 2001.
The District of Columbia was created in 1801 as the federal district of the United States, with territory previously held by the states of Maryland and Virginia ceded to the federal government of the United States for the purpose of creating its federal district, which would encompass the new national capital of the United States, the City of Washington. The district came into existence, with its own judges and marshals, through the District of Columbia Organic Act of 1801; previously it was the Territory of Columbia. According to specific language in the U.S. Constitution, it was 100 square miles (259 km2).
For reference, here are the 30-year climatology benchmarks for Reagan National Airport for April, along with our projections for the coming month:...Average snowfall: Trace; Forecast: 0 to trace