Geography of St. Louis, Missouri

St. Louis is located at coor dms|38|38|53|N|90|12|44|W|region:GR (38.648056, -90.212222).GR|1

The city is built primarily on bluffs and terraces that rise 100-200 feet above the western banks of the Mississippi River, just south of the Missouri-Mississippi confluence. Much of the area is a fertile and gently rolling prairie that features low hills and broad, shallow valleys. Both the Mississippi River and the Missouri River have cut large valleys with wide flood plains.

Limestone and dolomite of the Mississippian epoch underlies the area and much of the city is a karst area, with numerous sinkholes and caves, although most of the caves have been sealed shut; many springs are visible along the riverfront. Significant deposits of coal, brick clay, and millerite ore were once mined in the city, and the predominant surface rock, the "St. Louis Limestone", is used as dimension stone and rubble for construction.

The "St. Louis Geologic fault" is exposed along the bluffs and was the source of several historic minor earthquakes; it is part of the "St. Louis Anticline" which has some petroleum and natural gas deposits outside of the city. St. Louis is also just north of the New Madrid Seismic Zone which in 1811-12 produced a series of earthquakes that are the largest known in the contiguous United States. Seismologists estimate 90% probability of a magnitude 6.0 earthquake by 2040 and 7-10% probability of a magnitude 8.0, [ [http://www.livescience.com/forcesofnature/050622_new_madrid.html New Data Confirms Strong Earthquake Risk to Central U.S. | LiveScience ] ] such tremors could create significant damage across a large region of the central U.S. including St. Louis.

Near the southern boundary of the City of St. Louis (separating it from St. Louis County) is the River des Peres, virtually the only river or stream within the city limits that is not entirely underground. Most of River des Peres was either channelized or put underground in the 1920s and early 1930s. The lower section of the river was the site of some of the worst flooding of the Great Flood of 1993.

Near the central, western boundary of the city is Forest Park, site of the 1904 World's fair, the Louisiana Purchase Exposition of 1904, and the 1904 Summer Olympics, the first Olympic Games held in North America. At the time, St. Louis was the fourth most populous city in the United States.

The Missouri River forms the northern border of St. Louis County, exclusive of a few areas where the river has changed its course. The Meramec River forms most of its southern border. To the east is the City and the Mississippi River.

According to the United States Census Bureau, the city has a total area of 171.3 km² (66.2 mi²). 160.4 km² (61.9 mi²) of it is land and 11.0 km² (4.2 mi² or 6.39%) of it is water.

Metropolitan statistical area

The St. Louis Metropolitan Statistical Area is the 18th largest in the United States, and has a total population of 2,764,054 as of 2004. This area includes St. Louis County (1,016,235), the independent City of St. Louis (350,705), the Missouri counties of Saint Charles (320,734), Jefferson (210,397), Franklin (98,234), Lincoln (45,618) and Warren (27,809), and the Illinois counties of Madison (264,350), Saint Clair (259,132), Clinton (36,065), Monroe (30,491) and Jersey (22,320).

Cityscape

The city is divided into 79 neighborhoods. The divisions have no legal standing, although some neighborhood associations administer grants or hold veto power over historic-district development. Nevertheless, the social and political influence of neighborhood identity is profound. Some hold avenues of massive stone edifices built as palaces for heads of state visiting the 1904 World's Fair. Others offer tidy working-class bungalows, loft districts, or areas hard-hit by social problems and unemployment. Many of them have retained - quite consciously and deliberately - a camaraderie that is missing from many American towns today.

Among the best-known, architecturally significant, or well-visited neighborhoods are Downtown, Midtown, Benton Park, Carondelet, the Central West End, Clayton/Tamm (Dogtown), Dutchtown South, Forest Park Southeast, Grand Center, The Hill, Lafayette Square, Shaw (home to the Missouri Botanical Garden and named after the Garden's founder, Henry Shaw), Southwest Garden, Soulard (home of the second-largest Mardi Gras festival in the nation), Tower Grove East, Tower Grove South, Hortense Place (home to many grand mansions) and Wydown/Skinker.

Climate

St. Louis has a continental temperate climate, and has neither large mountains nor large bodies of water to moderate its temperature. The weather can be highly variable and dynamic. The area is affected by both cold Canadian arctic air, and also hot, humid tropical air from the Gulf of Mexico. The city has four distinct seasons. The average annual temperature for the years 1971-2000, recorded at nearby Lambert-St. Louis International Airport, is 56.3 °F (13.5 °C), and average precipitation is 38.75 inches (980 mm). The normal high temperature in July is 90 °F (32 °C), and the normal low temperature in January is 21 °F (−6 °C), although these values are often exceeded.

Temperatures of 100 °F (38 °C) or more occur no more than five days per year, while temperatures of 0 °F (-17.8 °C) or below occur less than 2 or 3 days per year on average (in the city proper). There is a distinct urban heat island effect and St. Louis also affects weather downstream. The official all-time record low is -22 °F (-30.0 °C) and the record high is 117 °F (47.2 °C). Hundreds were killed by extreme heat and humidity in 1995 and 1999. Emergency heating and cooling shelters are set up during extreme events, particularly when thunderstorms or ice storms knock out electricity, as happened in July 2006 and the winter of 2006-2007, respectively.

Winter is the driest season, averaging about 6 inches of total precipitation. Springtime, March through May, is typically the wettest season, with just under 10.5 inches. Dry spells of one or two weeks duration are common during the growing seasons. Minor urban flooding is a fairly common occurrence in the warm season, prolonged significant river flooding occasionally occurs, a notable example being the Great Flood of 1993.

A period of unseasonably warm weather late in autumn known as Indian summer is common – roses will still be in bloom as late as November or early December in some years. Weather conditions are highly variable - it is often said that if you don't like the weather in St. Louis, just wait 15 minutes.

Thunderstorms can be expected on 40 to 50 days per year. Seasonally, thunderstorms are most active from early spring through summer, though thunderstorms, including very destructive events, have occurred all throughout the year. A few of them will be severe with locally destructive winds and large hail, and occasionally accompanied by tornadoes (see St. Louis tornado history). Tornadoes are most common from March through June, though destructive tornadoes have occurred at multiple times all throughout the year. The two costliest and third deadliest tornadoes and the costliest hailstorm in history occurred in St. Louis. Other occasional weather hazards include blizzards and ice storms.

: External link: [http://www.weather.gov/climate/local_data.php?wfo=lsx National Weathsr Service information]

Flora and fauna

Before the founding of the city, the area was prairie and open forest maintained by burning by Native Americans. Trees are mainly oak, maple, and hickory, similar to the forests of the nearby Ozarks; common understory trees include Eastern Redbud, Serviceberry, and Flowering Dogwood. Riparian areas are forested with mainly American sycamore. Most of the residential area of the city is planted with large native shade trees. The largest native forest area is found in Forest Park. In Autumn, the changing color of the trees is notable. Most species here are typical of the Eastern Woodland, although numerous decorative non-native species are found; the most notable invasive species is Japanese honeysuckle, which is actively removed from some parks.

Large mammals found in the city include urbanized coyotes and occasionally a stray whitetail deer. Eastern Gray Squirrel, Cottontail rabbit, and other rodents are abundant, as well as the nocturnal and rarely seen Opossum. Large bird species are abundant in parks and include Canada goose, Mallard duck, as well as shorebirds, including the Great Egret and Great Blue Heron. Gulls are common along the Mississippi River; these species typically follow barge traffic. Winter populations of Bald Eagles are found by the Mississippi River around the Chain of Rocks Bridge. The city is on the Mississippi Flyway, used by migrating birds, and has a large variety of small bird species, common to the eastern U.S. The Eurasian Tree Sparrow, an introduced species, is limited in North America to the counties surrounding St. Louis. Tower Grove Park is a well-known birdwatching area in the city.

Frogs are commonly found in the springtime, especially after extensive wet periods. Common species include the American toad and species of chorus frogs, commonly called "spring peepers" that are found in nearly every pond. Some years have outbreaks of cicadas or ladybugs. Mosquitos and houseflies are common insect nuisances; because of this, windows are nearly universally fitted with screens, and "screened-in" porches are common in homes of the area. Populations of honey bees have sharply declined in recent years, and numerous species of pollinator insects have filled their ecological niche.

Adjacent communities

The following communities border the city of St. Louis directly:

*Cahokia, Illinois
*East Carondelet, Illinois
*East St. Louis, Illinois
*Madison, Illinois
*Sauget, Illinois
*Bellefontaine Neighbors, Missouri
*Clayton, Missouri
*Glasgow Village, Missouri
*Hillsdale, Missouri
*Jennings, Missouri

*Lemay, Missouri
*Mackenzie, Missouri
*Maplewood, Missouri
*Pine Lawn, Missouri
*Richmond Heights, Missouri
*Riverview, Missouri
*Shrewsbury, Missouri
*Spanish Lake, Missouri
*University City, Missouri
*Wellston, Missouri

In addition to the above named places, there are unincorporated parts of Madison County, Illinois, St. Clair County, Illinois, and St. Louis County, Missouri which border St. Louis. The Illinois communities of Brooklyn and Venice lie across the Mississippi River, but do not border St. Louis because the river itself is not part of their territory.

References