Editing Circle of latitude (section)

==Other notable parallels==
{{see also|Baseline (surveying)}}

A number of sub-national and international [[border]]s were intended to be defined by, or are approximated by, parallels. Parallels make convenient borders in the northern hemisphere because astronomic latitude can be roughly measured (to within a few tens of metres) by sighting the [[Polaris|North Star]].

{| class="wikitable"
|-
! Parallel !! Description
|- valign="center"
| [[81st parallel north|81°N]]
| rowspan="2" | In [[Svalbard]], [[Norway]], the northern and southern limits of the area comprised by the [[Svalbard Treaty]] of 9 February 1920.
|- valign="top"
| [[74th parallel north|74°N]]
|- valign="top"
| [[70th parallel north|70°N]]
| On [[Victoria Island (Canada)|Victoria Island]], Canada, two sections of the border between [[Northwest Territories]] and [[Nunavut]].
|- valign="top"
| [[60th parallel north|60°N]]
| In Canada, the southern border of [[Yukon]] with the northern border of [[British Columbia]]; the southern border of Northwest Territories with the northern borders of British Columbia, [[Alberta]] and [[Saskatchewan]]; and the southern border of mainland Nunavut with the northern border of [[Manitoba]], leading to the expression "north of sixty" for the territories.
|- valign="top"
| [[Parallel 54°40′ north|54°40′N]]
| The border between 19th century Russian territories to the north and conflicting American and British land claims in western North America. The conflicting claims led to the [[Oregon boundary dispute]] between Britain and the United States, giving rise to the slogan "Fifty-four forty or fight."
|- valign="top"
| [[52nd parallel north|52°N]]
| In Canada, part of the border between [[Newfoundland and Labrador]] and [[Quebec]].
|- valign="top"
| [[51st parallel north|51°N]]
| The southern limit of [[Russian America]] from 1799 to 1821.
|- valign="top"
|[[49th parallel north|49°N]]
| Much of [[Canada–United States border|the border]] between Canada and the United States, from British Columbia to Manitoba; "49th parallel" is a common expression for the border, though the majority of Canada's population actually lives south of the parallel.
|- valign="top"
|[[48th parallel north|48°N]]
| In Canada, part of the border between Quebec and [[New Brunswick]].
|- valign="top"
|[[46th parallel north|46°N]]
| In the United States, part of the border between [[Washington (state)|Washington]] and [[Oregon]].
|- valign="top"
| [[45th parallel north|45°N]]
| Approximates the portion of the [[Canada–United States border]] between [[Quebec]] (Canada) and [[New York (state)|New York]] and [[Vermont]] (US). Also approximates most of the border between [[Montana]] and [[Wyoming]].
|- valign="top"
| 43°30′N
| In the US, the border between [[Minnesota]] and [[Iowa]].
|- valign="top"
| [[43rd parallel north|43°N]]
| In the US, much of the border between [[South Dakota]] and [[Nebraska]].
|- valign="top"
| 42°30′N
| In the US, the border between [[Wisconsin]] and [[Illinois]].
|- valign="top"
| [[42nd parallel north|42°N]]
| Originally the northward limit of [[New Spain]].  In the US, the southern borders of [[Oregon]] and [[Idaho]] where they meet the northern borders of [[California]], [[Nevada]] and [[Utah]]. The parallel also defines much of the border between [[Pennsylvania]] and [[New York (state)|New York]].
|- valign="top"
| [[41st parallel north|41°N]]
| In the US, part of the border between Wyoming and Utah, the border between Wyoming and [[Colorado]], and part of the border between Nebraska and Colorado.
|- valign="top"
| [[40th parallel north|40°N]]
| In the US, the border between Nebraska and [[Kansas]]. The parallel was originally chosen for the [[Mason–Dixon line]], but the line was moved several miles south to avoid bisecting the city of [[Philadelphia]].
|- valign="top"
| [[38th parallel north|38°N]]
| The boundary between the [[Soviet Union|Soviet]] and [[United States of America|American]] occupation zones in Korea, and later between [[North Korea]] and [[South Korea]], from 1945 until the [[Korean War]] (1950–1953).
|- valign="top"
| [[37th parallel north|37°N]]
| In the US, the southern border of Utah with the northern border of [[Arizona]]. The southern border of Colorado with the northern borders of [[New Mexico]] and [[Oklahoma]]. The southern border of Kansas with the northern border of Oklahoma.
|- valign="top"
| [[Parallel 36°30′ north|36°30′N]]
| [[Image:Missouri Compromise Line.svg|thumb|100px]]The historic [[Missouri Compromise]] line (the historic division between slave and free states). In the US, defines part of the border between Oklahoma and [[Texas]], most of the border between [[Missouri]] and [[Arkansas]]. Geographically it is a Westward extension of the border between [[Virginia]] and [[North Carolina]] and part of the border between [[Kentucky]] and [[Tennessee]].
|- valign="top"
| [[36th parallel north|36°N]]
| In the US, a short section of the border between the [[Missouri Bootheel]] and Arkansas.
|- valign="top"
| [[35th parallel north|35°N]]
| In the US, the southern border of Tennessee, which meets [[Mississippi]], [[Alabama]] and [[Georgia (U.S. state)|Georgia]]. Also, part of the border between North Carolina and Georgia.
|- valign="top"
| [[33rd parallel north|33°N]]
| In the US, the southern border of Arkansas, which meets the northern border of [[Louisiana]], is approximated by the parallel. Historically, it defined the southern border of the [[Louisiana Territory]].
|- valign="top"
| [[32nd parallel north|32°N]]
| In the US, part of the border between New Mexico and Texas.
|- valign="top"
| 31°20′N
| Part of the border between the US and [[Mexico]] ([[Sonora]] and [[Chihuahua (state)|Chihuahua]]); the southern border of Arizona and the [[New Mexico Bootheel]].
|- valign="top"
| [[31st parallel north|31°N]]
| Part of the border between [[Iran]] and [[Iraq]]. In the US, part of the border between [[Mississippi]] and [[Louisiana]], and part of the border between [[Alabama]] and [[Florida]].
|- valign="top"
| [[28th parallel north|28°N]]
| In Mexico, the border between [[Baja California]] and [[Baja California Sur]].
|- valign="top"
| [[26th parallel north|26°N]]
| Part of the border between [[Western Sahara]] (claimed by [[Morocco]]) and [[Mauritania]].
|- valign="top"
| [[25th parallel north|25°N]]
| Part of the border between Mauritania and [[Mali]].
|- valign="top"
| [[22nd parallel north|22°N]]
| Much of the border between [[Egypt]] and [[Sudan]], partly disputed (see also [[Hala'ib Triangle]]).
|- valign="top"
| [[20th parallel north|20°N]]
| A short section of the border between [[Libya]] and Sudan, and within Sudan, the northern border of the [[Darfur]] region.
|- valign="top"
| [[17th parallel north|17°N]]
| The division between Republic of Vietnam ([[South Vietnam]]) and Democratic Republic of Vietnam ([[North Vietnam]]) during the [[Vietnam War]].
|- valign="top"
| [[15th parallel north|15°N]]
| ''de facto'' maritime border between [[Honduras]] and [[Nicaragua]].<ref>{{cite web|url=http://www.icj-cij.org/docket/files/120/13746.pdf|title=Maritime Delimitation between Nicaragua and Honduras in the Caribbean Sea (Nicaragua v. Honduras)|access-date=2014-05-13|archive-url=https://web.archive.org/web/20150924042116/http://www.icj-cij.org/docket/files/120/13746.pdf|archive-date=2015-09-24|url-status=dead}}</ref>
|- valign="top"
| 13°05′N
| Part of the border between [[Chad]] and [[Cameroon]], over a stretch of 41.6&nbsp;km, partly in [[Lake Chad]]
|- valign="top"
| [[10th parallel north|10°N]]
| Part of the border between [[Guinea]] and [[Sierra Leone]].
|- valign="top"
| [[8th parallel north|8°N]]
| Part of the border between [[Somalia]] and [[Ethiopia]].
|- valign="top"
| [[1st parallel north|1°N]]
| Part of the border between [[Equatorial Guinea]] and [[Gabon]].
|- valign="top"
| [[1st parallel south|1°S]]
| Most of the border between [[Uganda]] and [[Tanzania]], and a very short section of the border between [[Kenya]] and Tanzania in [[Lake Victoria]].
|- valign="top"
| [[7th parallel south|7°S]]
| A short section of the border between [[Democratic Republic of the Congo]] and [[Angola]].
|- valign="top"
| [[8th parallel south|8°S]]
| Two short sections of the border between Democratic Republic of the Congo and Angola.
|- valign="top"
| [[10th parallel south|10°S]]
| A short section of the border between [[Brazil]] and [[Peru]].
|- valign="top"
| [[13th parallel south|13°S]]
| Part of the border between Angola and [[Zambia]].
|- valign="top"
| [[16th parallel south|16°S]]
| Part of the border between [[Mozambique]] and [[Zimbabwe]].
|- valign="top"
| [[22nd parallel south|22°S]]
| A short section of the border between [[Namibia]] and [[Botswana]], and parts of the border between [[Bolivia]] and [[Argentina]].
|- valign="top"
| [[26th parallel south|26°S]]
| In [[Australia]], the border between [[South Australia]] and the [[Northern Territory]], and part of the border between South Australia and [[Queensland]].
|- valign="top"
| [[28th parallel south|28°S]]
| In Argentina, the border between [[Chaco Province]] and [[Santa Fe Province]].
|- valign="top"
| [[29th parallel south|29°S]]
| In Australia, much of the border between Queensland and [[New South Wales]].
|- valign="top"
| [[35th parallel south|35°S]]
| In Argentina, part of the border between [[Córdoba Province, Argentina|Córdoba Province]] and [[La Pampa Province]].
|- valign="top"
| [[36th parallel south|36°S]]
| In Argentina, part of the border between [[Mendoza Province]] and La Pampa Province, and part of the border between [[San Luis Province]] and La Pampa Province.
|- valign="top"
| [[42nd parallel south|42°S]]
| In Argentina, the border between [[Río Negro Province]] and [[Chubut Province]].
|- valign="top"
| [[46th parallel south|46°S]]
| In Argentina, the border between Chubut Province and [[Santa Cruz Province (Argentina)|Santa Cruz Province]].
|- valign="top"
| [[52nd parallel south|52°S]]
| Part of the border between Argentina and [[Chile]].
|- valign="top"
| [[60th parallel south|60°S]]
| The northern boundary of [[Antarctica]] for the purposes of the [[Antarctic Treaty System]] (see [http://sd-www.jhuapl.edu/FlareGenesis/Antarctica/1999/pictures/antarctica_pol_map.jpg map]). The northern boundary of the [[Southern Ocean]].
|}