Geography of Wyoming

{{Further|Climate change in Wyoming}}

File:Köppen Climate Types Wyoming.png of Wyoming, using 1991-2020 climate normals.]]

File:Wyoming.JPG, leaving Utah]]

File:Autumn in the Bighorn Mountains.JPG

Wyoming's climate is generally semi-arid and continental (Köppen climate classification BSk), and is drier and windier in comparison to most of the United States with greater temperature extremes. Much of this is due to the topography of the state. Summers in Wyoming are warm with July high temperatures averaging between {{convert|80|and|90|°F|°C|abbr=on}} in most of the state. With increasing elevation, however, this average drops rapidly with locations above {{convert|9000|ft|m}} averaging around {{convert|70|°F|°C|abbr=on}}. Summer nights throughout the state are characterized by a rapid cooldown with even the hottest locations averaging in the {{convert|50|–|60|F|C}} range at night. In most of the state, most of the precipitation tends to fall in the late spring and early summer. Winters are cold, but are variable with periods of sometimes extreme cold interspersed between generally mild periods, with Chinook winds providing unusually warm temperatures in some locations.{{cite web |last=Burrows |first=Alvin T. |date=c. 1901 |title=The Chinook Winds |url=http://naldc-legacy.nal.usda.gov/naldc/download.xhtml?id=IND43621096&content=PDF |website=Yearbook of the Department of Agriculture |publisher=US Department of Agriculture |access-date=6 February 2016}}

Wyoming is a dry state with much of the land receiving less than {{convert|10|in|mm}} of rainfall per year. Precipitation depends on elevation with lower areas in the Big Horn Basin averaging {{convert|5|-|8|in|mm}}, making the area nearly a true desert. The lower areas in the North and on the eastern plains typically average around {{convert|10|-|12|in|mm}}, making the climate there semi-arid. Some mountain areas do receive a good amount of precipitation, {{convert|20|in|mm}} or more, much of it as snow, sometimes {{convert|200|in|cm}} or more annually. The state's highest recorded temperature is {{convert|114|F|C}} at Basin on July 12, 1900,{{Cite web|title=Record Highest Temperatures by State|url=https://www.infoplease.com/math-science/weather/record-highest-temperatures-by-state|access-date=2021-03-24|website=www.infoplease.com|language=en}}{{Cite web|title=Wyoming: Temperature Extremes|url=https://www.infoplease.com/math-science/weather/wyoming-temperature-extremes|access-date=2021-03-24|website=www.infoplease.com|language=en}} and the lowest recorded temperature is {{convert|-66|F|C}} at Riverside on February 9, 1933.

The number of thunderstorm days vary across the state with the southeastern plains of the state having the most days of thunderstorm activity. Thunderstorm activity in the state is highest during the late spring and early summer. The southeastern corner of the state is the most vulnerable part of the state to tornado activity. Moving away from that point and westwards, the incidence of tornadoes drops dramatically with the west part of the state showing little vulnerability. Tornadoes, where they occur, tend to be small and brief, unlike some of those that occur farther east. The most destructive tornado to occur in Wyoming happened on July 16, 1979, in Cheyenne and caused one death and 40 injuries.{{cite web|url=http://www.tornadohistoryproject.com|title=Tornado History Project: Maps and Statistics|website=Tornadohistoryproject.com|access-date=January 9, 2018|archive-url=https://web.archive.org/web/20180117024312/http://www.tornadohistoryproject.com/|archive-date=January 17, 2018|url-status=usurped}}[http://www.bangladeshtornadoes.org/071679/071679terrain.html]{{dead link|date=August 2017|bot=InternetArchiveBot|fix-attempted=yes}}

{{Cheyenne, Wyoming weatherbox}}

{{Weather box

|width=auto

|location = Basin, Wyoming (1991–2020 normals, extremes 1898–present)

|single line = Yes

|collapsed = Yes

|Jan record high F = 64

|Feb record high F = 73

|Mar record high F = 82

|Apr record high F = 90

|May record high F = 99

|Jun record high F = 110

|Jul record high F = 112

|Aug record high F = 115

|Sep record high F = 102

|Oct record high F = 91

|Nov record high F = 77

|Dec record high F = 67

|year record high F =

|Jan avg record high F = 47.9

|Feb avg record high F = 55.1

|Mar avg record high F = 72.3

|Apr avg record high F = 81.9

|May avg record high F = 89.0

|Jun avg record high F = 97.4

|Jul avg record high F = 101.9

|Aug avg record high F = 99.8

|Sep avg record high F = 94.7

|Oct avg record high F = 82.9

|Nov avg record high F = 64.2

|Dec avg record high F = 51.3

|year avg record high F = 102.4

|Jan high F = 32.4

|Feb high F = 39.1

|Mar high F = 54.1

|Apr high F = 63.0

|May high F = 72.8

|Jun high F = 83.7

|Jul high F = 92.7

|Aug high F = 91.0

|Sep high F = 79.3

|Oct high F = 62.9

|Nov high F = 46.4

|Dec high F = 33.8

|year high F =

|Jan mean F = 20.6

|Feb mean F = 26.8

|Mar mean F = 40.7

|Apr mean F = 49.8

|May mean F = 59.8

|Jun mean F = 69.2.

|Jul mean F = 76.5

|Aug mean F = 74.1

|Sep mean F = 63.4

|Oct mean F = 49.2

|Nov mean F = 34.6

|Dec mean F = 22.6

|year mean F =

|Jan low F = 8.8

|Feb low F = 14.6

|Mar low F = 27.4

|Apr low F = 36.5

|May low F = 46.8

|Jun low F = 54.7

|Jul low F = 60.3

|Aug low F = 57.2

|Sep low F = 47.5

|Oct low F = 35.5

|Nov low F = 22.8

|Dec low F = 11.4

|year low F =

|Jan avg record low F = -16.3

|Feb avg record low F = -10.3

|Mar avg record low F = 5.1

|Apr avg record low F = 19.2

|May avg record low F = 28.8

|Jun avg record low F = 40.4

|Jul avg record low F = 48.6

|Aug avg record low F = 43.9

|Sep avg record low F = 32.0

|Oct avg record low F = 17.1

|Nov avg record low F = -0.6

|Dec avg record low F = -9.7

|year avg record low F = -22.3

|Jan record low F = -43

|Feb record low F = -51

|Mar record low F = -31

|Apr record low F = -4

|May record low F = 18

|Jun record low F = 30

|Jul record low F = 36

|Aug record low F = 34

|Sep record low F = 14

|Oct record low F = -7

|Nov record low F = -28

|Dec record low F = -43

|year record low F =

|precipitation colour = green

|Jan precipitation inch = 0.24

|Feb precipitation inch = 0.32

|Mar precipitation inch = 0.31

|Apr precipitation inch = 0.75

|May precipitation inch = 1.37

|Jun precipitation inch = 1.04

|Jul precipitation inch = 0.41

|Aug precipitation inch = 0.32

|Sep precipitation inch = 0.95

|Oct precipitation inch = 0.79

|Nov precipitation inch = 0.36

|Dec precipitation inch = 0.30

|year precipitation inch =

|unit precipitation days = 0.01 in

|Jan precipitation days = 3.4

|Feb precipitation days = 3.6

|Mar precipitation days = 3.1

|Apr precipitation days = 5.1

|May precipitation days = 7.1

|Jun precipitation days = 6.0

|Jul precipitation days = 3.2

|Aug precipitation days = 3.6

|Sep precipitation days = 4.7

|Oct precipitation days = 4.0

|Nov precipitation days = 3.3

|Dec precipitation days = 3.3

|year precipitation days = 50.4

|Jan snow inch = 3.4

|Feb snow inch = 4.1

|Mar snow inch = 2.3

|Apr snow inch = 1.5

|May snow inch = 0.1

|Jun snow inch = 0.0

|Jul snow inch = 0.0

|Aug snow inch = 0.0

|Sep snow inch = 0.2

|Oct snow inch = 1.5

|Nov snow inch = 3.0

|Dec snow inch = 4.0

|year snow inch =

|unit snow days = 0.1 in

|Jan snow days = 2.5

|Feb snow days = 2.6

|Mar snow days = 1.4

|Apr snow days = 0.7

|May snow days = 0.1

|Jun snow days = 0.0

|Jul snow days = 0.0

|Aug snow days = 0.0

|Sep snow days = 0.1

|Oct snow days = 0.7

|Nov snow days = 1.7

|Dec snow days = 2.3

|year snow days =

|source 1 = NOAA{{cite web

| url = https://www.weather.gov/wrh/climate?wfo=riw

| title = NOWData - NOAA Online Weather Data

| publisher = National Oceanic and Atmospheric Administration

}}{{cite web

| url = https://www.ncei.noaa.gov/access/services/data/v1?dataset=normals-monthly-1991-2020&startDate=0001-01-01&endDate=9996-12-31&stations=USC00480540&format=pdf

| title = Summary of Monthly Normals 1991-2020

| publisher = National Oceanic and Atmospheric Administration

| accessdate = October 19, 2021

}} }}

As specified in the designating legislation for the Territory of Wyoming, Wyoming's borders are lines of latitude 41°N and 45°N, and longitude 104°3'W and 111°3'W (27 and 34 west of the Washington Meridian)—a geodesic quadrangle{{cite web|author=Willam J. Gribb |author2=Lawrence M. Ostrech |title=Databases and Algorithms to Determine the Boundary of Wyoming |publisher=University of Wyoming, Department of Geography |url=http://gis.esri.com/library/userconf/proc04/docs/pap1718.pdf |access-date=December 14, 2008 |url-status=dead |archive-url=https://web.archive.org/web/20081217015637/http://gis.esri.com/library/userconf/proc04/docs/pap1718.pdf |archive-date=December 17, 2008 |df=mdy-all }} (except the north and south borders are circles of latitude which are not geodesics). Wyoming is one of only three states (the others being Colorado and Utah) to have borders defined by only "straight" lines. Due to surveying inaccuracies during the 19th century, Wyoming's legal border deviates from the true latitude and longitude lines by up to {{convert|1/2|mi|km|spell=in}} in some spots, especially in the mountainous region along the 45th parallel.{{cite web |url=http://www.maa.org/mathtourist/mathtourist_08_30_07.html |title=Rectangular States and Kinky Borders |author=Ivars Peterson |access-date=December 14, 2008 |url-status=dead |archive-url=https://web.archive.org/web/20080705160310/http://www.maa.org/mathtourist/mathtourist_08_30_07.html |archive-date=July 5, 2008}} Wyoming is bordered on the north by Montana, on the east by South Dakota and Nebraska, on the south by Colorado, on the southwest by Utah, and on the west by Idaho. It is the tenth largest state in the United States in total area, containing {{convert|97814|sqmi|km2}} and is made up of 23 counties. From the north border to the south border it is {{convert|276|mi|km}}; and from the east to the west border is {{convert|365|mi|km}} at its south end and {{convert|342|mi|km}} at the north end.

File:Barns grand tetons.jpg]]

File:Cattle Drive near Pinedale, WY (14963962303).jpg valley]]

The Great Plains meet the Rocky Mountains in Wyoming. The state is a great plateau broken by many mountain ranges. Surface elevations range from the summit of Gannett Peak in the Wind River Mountain Range, at {{convert|13804|ft|m}}, to the Belle Fourche River valley in the state's northeast corner, at {{convert|3125|ft|m}}. In the northwest are the Absaroka, Owl Creek, Gros Ventre, Wind River, and the Teton ranges. In the north central are the Big Horn Mountains; in the northeast, the Black Hills; and in the southern region the Laramie, Snowy, and Sierra Madre ranges.

The Snowy Range in the south central part of the state is an extension of the Colorado Rockies both in geology and in appearance. The Wind River Range in the west central part of the state is remote and includes more than 40 mountain peaks in excess of {{convert|13000|ft|m|abbr=on}} tall in addition to Gannett Peak, the highest peak in the state. The Big Horn Mountains in the north central portion are somewhat isolated from the bulk of the Rocky Mountains.

The Teton Range in the northwest extends for {{convert|50|mi|km}}, part of which is included in Grand Teton National Park. The park includes the Grand Teton, the second highest peak in the state.

The Continental Divide spans north–south across the central portion of the state. Rivers east of the divide drain into the Missouri River Basin and eventually the Gulf of Mexico. They are the North Platte, Wind, Big Horn and the Yellowstone rivers. The Snake River in northwest Wyoming eventually drains into the Columbia River and the Pacific Ocean, as does the Green River through the Colorado River Basin.

The Continental Divide forks in the south central part of the state in an area known as the Great Divide Basin where water that precipitates onto or flows into it cannot reach an ocean—it all sinks into the soil and eventually evaporates.

Several rivers begin in or flow through the state, including the Yellowstone River, Bighorn River, Green River, and the Snake River.

Much of Wyoming is covered with large basins containing different eco-regions, from shrublands to smaller patches of desert.{{cite web|url=http://www.landscope.org/explore/natural_geographies/ecoregions/Wyoming%20Basins/|publisher=Landscope|date=June 26, 2012|access-date=March 11, 2021|archive-url=https://web.archive.org/web/20200226072841/http://www.landscope.org/explore/natural_geographies/ecoregions/Wyoming%20Basins/|archive-date=February 26, 2020|url-status=live| title= Wyoming Basins Ecoregion }} Regions of the state classified as basins contain everything from large geologic formations to sand dunes and vast unpopulated spaces.{{cite web|url=https://hort.purdue.edu/newcrop/cropmap/ecoreg/descript.html#18|website=hort.purdue.edu|publisher=Purdue University|date=April 1, 2000|access-date=March 9, 2021|archive-url=https://web.archive.org/web/20210211032359/https://hort.purdue.edu/newcrop/cropmap/ecoreg/descript.html|archive-date=February 11, 2021|url-status=live| title=Level III Ecoregions of the Continental United States}} Basin landscapes are typically at lower elevations and include rolling hills, valleys, mesas, terraces and other rugged terrain, but also include natural springs as well as rivers and artificial reservoirs.{{cite web|url=ftp://newftp.epa.gov/EPADataCommons/ORD/Ecoregions/wy/wy_front.pdf|publisher=EPA|date=Jan 1, 2004|access-date=March 9, 2021|archive-url=https://web.archive.org/web/20220509200703/ftp://newftp.epa.gov/EPADataCommons/ORD/Ecoregions/wy/wy_front.pdf|archive-date=2022-05-09|url-status=dead|title=Wyoming Eco-Regions}} They have common plant species such as various subspecies of sagebrush, juniper and grasses such as wheatgrass, but basins are known for their diversity of plant and animal species.

{{Main list|List of islands of Wyoming}}

Wyoming has 32 named islands; the majority are in Jackson Lake and Yellowstone Lake, within Yellowstone National Park in the northwest portion of the state. The Green River in the southwest also contains a number of islands.

{{Main list|List of counties in Wyoming}}

The state of Wyoming has 23 counties. Thirteen were there when Wyoming became a state in 1890 and ten more have been created since then.{{cite web |url=http://wyoming.gov/general/history.asp |title=General Facts About Wyoming |access-date=2007-07-20 |work=State of Wyoming |archive-url = https://web.archive.org/web/20070512143401/http://wyoming.gov/general/history.asp |archive-date = 2007-05-12}}

Wyoming license plates have a number on the left that indicates the county where the vehicle is registered, ranked by an earlier census.{{cite web|url=http://eadiv.state.wy.us/demog_data/cntycity_hist.htm|publisher=U.S. Census, State of Wyoming|title=Historical decennial census population for Wyoming counties, cities, and towns|access-date=September 24, 2012|archive-url=https://web.archive.org/web/20170708181724/http://eadiv.state.wy.us/demog_data/cntycity_hist.htm|archive-date=July 8, 2017|url-status=live}} Specifically, the numbers are representative of the property values of the counties in 1930.{{cite web|url=http://www.tetonat.com/2010/07/08/interesting-wyoming-license-plate-fact/|title=TetonAT.com—Interesting Wyoming License Plate Fact|website=Tetonat.com|access-date=September 4, 2017|archive-url=https://web.archive.org/web/20170904203501/http://www.tetonat.com/2010/07/08/interesting-wyoming-license-plate-fact/|archive-date=September 4, 2017|url-status=live}} The county license plate numbers are:

File:CheyenneWyoming.jpg]]

File:Casperskyline.jpg]]

File:RockSpringsWY.jpg]]

File:EvanstonWyoming.jpg]]

File:DowntownRawlins.jpg]]

File:Grand Targhee Ski Resort, February 2021.jpg and Jackson Hole.]]

The State of Wyoming has 99 incorporated municipalities.

In 2005, 50.6% of Wyomingites lived in one of the 13 most populous Wyoming municipalities.

The United States Census Bureau has defined two Metropolitan Statistical Areas (MSA) and seven Micropolitan Statistical Areas (MiSA) for the State of Wyoming. In 2008, 30.4% of Wyomingites lived in either of the Metropolitan Statistical Areas, and 73% lived in either a Metropolitan Statistical Area or a Micropolitan Statistical Area.

• Rocky Mountains
• Geography of Montana
• Continental Divide

{{notelist}}

{{reflist}}

Category:Geography of Wyoming