Twilight: Civil, nautical, astronomical; southernmost / northernmost latitudes.
The extreme southernmost / northernmost latitudes in the Northern / Southern Hemispheres that Civil, Nautical, and Astronomical Twilight can last through local solar midnight or twilight all night, at the Northern / Southern Hemisphere's solstices, also the Arctic, and Antarctic latitudes for these dates and times; calculated using the PHP Science Labs Website, Obliquity of the Ecliptic and Nutation in Obliquity (using IAU 2000B nutation series); i.e true obliquity of the ecliptic, as used by the National Land Survey of Finland, Finnish Geodetic Institute, and the GIT Barents website:
2013 Northern Hemisphere, summer solstice:
Arctic / Antarctic Circle 66° 33’ 52.049” N / S
Civil twilight 60° 33’ 52.049” N
Nautical twilight 54° 33’ 52.049” N
Astronomical twilight 48° 33’ 52.049” N
2013 Southern Hemisphere, summer solstice:
Antarctic / Arctic Circle 66° 33’ 53.249” S / N
Civil twilight 60° 33’ 53.249” S
Nautical twilight 54° 33’ 53.249” S
Astronomical twilight 48° 33' 53.249” S
2014 Northern Hemisphere, summer solstice:
Arctic / Antarctic Circle 66° 33’ 54.232” N / S
Civil twilight 60° 33’ 54.232” N
Nautical twilight 54° 33’ 54.232” N
Astronomical twilight 48° 33’ 54.232” N
2014 Southern Hemisphere, summer solstice:
Antarctic / Arctic Circle 66° 33’ 55.178” S / N
Civil twilight 60° 33’ 55.178” S
Nautical twilight 54° 33’ 55.178” S
Astronomical twilight 48° 33’ 55.178” S
2015 Northern Hemisphere, summer solstice:
Arctic / Arctic Circle 66° 33’ 55.571” N / S
Civil twilight 60° 33’ 55.571” N
Nautical twilight 54° 33’ 55.571” N
Astronomical twilight 48° 33’ 55.571” N
2015 Southern Hemisphere, summer solstice:
Antarctic / Arctic Circle 66° 33’ 55.890” S / N
Civil twilight 60° 33’ 55.890” S
Nautical twilight 54° 33’ 55.890” S
Astronomical twilight 48° 33’ 55.890” S
2016 Northern Hemisphere, summer solstice: Circumference or length:
Arctic / Antarctic Circle 66° 33’ 55.941” N / S 15,982.926417462362 km or 9,931.330043460169 miles.
Civil twilight 60° 33’ 55.941” N 19,744.162762640396 km or 12,268.453955549836 miles.
Nautical twilight 54° 33’ 55.941” N 23,286.147101212778 km or 14,469.340986894522 miles.
Astronomical twilight 48° 33’ 55.941” N 26,570.194478309322 km or 16,509.953420964891miles.
2016 Southern Hemisphere, summer solstice: Circumference or length:
Antarctic / Arctic Circle 66° 33’ 55.524” S / N 15,983.000884214218 km or 9,931.376314954552 miles.
Civil twilight 60° 33’ 55.524” S 19,744.233388049778 km or 12,268.497840144666 miles.
Nautical twilight 54° 33’ 55.524” S 23,286.213111060426 km or 14,469.382003512255 miles.
Astronomical twilight 48° 33’ 55.524” S 26,570.255154469880 km or 16,509.991123383118 miles.
2017 Northern Hemisphere, summer solstice: Circumference or length:
Arctic / Antarctic Circle 66° 33’ 55.078” N / S 15,983.081 km or 9,931.426 international miles.
Civil twilight 60° 33’ 55.078” N 19,744.309 km or 12,268.545 international miles.
Nautical twilight 54° 33’ 55.078” N 23,286.284 km or 14,469.426 international miles.
Astronomical twilight 48° 33’ 55.078” N 26,570.320 km or 16,510.031 international miles.
2017 Southern Hemisphere, summer solstice: Circumference or length:
Antarctic / Arctic Circle 66° 33’ 54.374” S / N 15,983.206 km or 9,931.504 international miles.
Civil twilight 60° 33’ 54.374” S 19,744.428 km or 12,268.619 international miles.
Nautical twilight 54° 33’ 54.374” S 23,286.395 km or 14,469.495 international miles.
Astronomical twilight 48° 33’ 54.374” S 26,570.422 km or 16,510.095 international miles.
2018 Northern Hemisphere, summer solstice: Circumference or length:
Arctic / Antarctic Circle 66° 33’ 53.296” N / S 15,983.399 km or 9,931.624 international miles.
Civil Twilight 60° 33’ 53.296” N / S 19,744.611 km or 12,268.732 international miles.
Nautical Twilight 54° 33’ 53.296” N / S 23,286.566 km or 14,469.601 international miles.
Astronomical Twilight 48° 33’ 53.296” N / S 26,570.579 km or 16,510.192 international miles.
2018 Southern Hemisphere, summer solstice: Circumference or length:
Antarctic / Arctic Circle 66° 33’ 52.385” S / N 15,983.561 km or 9,931.724 international miles.
Civil twilight 60° 33’ 52.385” S 19,744.765 km or 12,268.828 international miles.
Nautical twilight 54° 33’ 52.385” S 23,286.710 km or 14,469.691 international miles.
Astronomical twilight 48° 33’ 52.385” S 26,570.712 km or 16,510.275 international miles.
2019 Northern Hemisphere, summer solstice:
Arctic / Antarctic Circle 66° 33’ 51.083” N / S
Civil twilight 60° 33’ 51.083” N
Nautical twilight 54° 33’ 51.083” N
Astronomical twilight 48° 33’ 51.083” N
2019 Southern Hemisphere, summer solstice:
Antarctic / Arctic Circle 66° 33’ 49.748” S / N
Civil twilight 60° 33’ 49.748” S
Nautical twilight 54° 33’ 49.748” S
Astronomical twilight 48° 33’ 49.748” S
2020 Northern Hemisphere, summer solstice:
Arctic / Antarctic Circle 66° 33’ 48.571” N / S
Civil twilight 60° 33’ 48.571” N
Nautical twilight 54° 33’ 48.571” N
Astronomical twilight 48° 33’ 48.571” N
2020 Southern Hemisphere, summer solstice:
Antarctic / Arctic Circle 66° 33’ 47.077” S / N
Civil twilight 60° 33’ 47.077” S
Nautical twilight 54° 33’ 47.077” S
Astronomical twilight 48° 33’ 47.077” S
Distances personally calculated, using Charles Karney's Online rhumb line calculations using the RhumbSolve utility: "RhumbSolve is accurate to about 15 nanometers (for the WGS84 ellipsoid)" or 0.000015 of a millimetre/millimeter or 0.00000059 of an inch. In emails to me from Charles Karney: "The accuracy of 15 nanometers that I quote is for paths up to half-way round the earth." "The accuracy for the Airy" [1830] "ellipsoid will be (very nearly) the same as for the WGS84 ellipsoid because the parameters are roughly the same." On RhumbSolve online: "RhumbSolve performs rhumb line calculations". "The path with a constant heading between two points on the ellipsoid at (lat1, lon1) and (lat2, lon2) is called the rhumb line (or loxodrome)". "NOTE: the rhumb line is not the shortest path between two points; that is the geodesic and it is calculated by GeodSolve."
See also: http://www.gandraxa.com/length_of_day.xml
2013 Northern Hemisphere, summer solstice:
Arctic / Antarctic Circle 66° 33’ 52.049” N / S
Civil twilight 60° 33’ 52.049” N
Nautical twilight 54° 33’ 52.049” N
Astronomical twilight 48° 33’ 52.049” N
2013 Southern Hemisphere, summer solstice:
Antarctic / Arctic Circle 66° 33’ 53.249” S / N
Civil twilight 60° 33’ 53.249” S
Nautical twilight 54° 33’ 53.249” S
Astronomical twilight 48° 33' 53.249” S
2014 Northern Hemisphere, summer solstice:
Arctic / Antarctic Circle 66° 33’ 54.232” N / S
Civil twilight 60° 33’ 54.232” N
Nautical twilight 54° 33’ 54.232” N
Astronomical twilight 48° 33’ 54.232” N
2014 Southern Hemisphere, summer solstice:
Antarctic / Arctic Circle 66° 33’ 55.178” S / N
Civil twilight 60° 33’ 55.178” S
Nautical twilight 54° 33’ 55.178” S
Astronomical twilight 48° 33’ 55.178” S
2015 Northern Hemisphere, summer solstice:
Arctic / Arctic Circle 66° 33’ 55.571” N / S
Civil twilight 60° 33’ 55.571” N
Nautical twilight 54° 33’ 55.571” N
Astronomical twilight 48° 33’ 55.571” N
2015 Southern Hemisphere, summer solstice:
Antarctic / Arctic Circle 66° 33’ 55.890” S / N
Civil twilight 60° 33’ 55.890” S
Nautical twilight 54° 33’ 55.890” S
Astronomical twilight 48° 33’ 55.890” S
2016 Northern Hemisphere, summer solstice: Circumference or length:
Arctic / Antarctic Circle 66° 33’ 55.941” N / S 15,982.926417462362 km or 9,931.330043460169 miles.
Civil twilight 60° 33’ 55.941” N 19,744.162762640396 km or 12,268.453955549836 miles.
Nautical twilight 54° 33’ 55.941” N 23,286.147101212778 km or 14,469.340986894522 miles.
Astronomical twilight 48° 33’ 55.941” N 26,570.194478309322 km or 16,509.953420964891miles.
2016 Southern Hemisphere, summer solstice: Circumference or length:
Antarctic / Arctic Circle 66° 33’ 55.524” S / N 15,983.000884214218 km or 9,931.376314954552 miles.
Civil twilight 60° 33’ 55.524” S 19,744.233388049778 km or 12,268.497840144666 miles.
Nautical twilight 54° 33’ 55.524” S 23,286.213111060426 km or 14,469.382003512255 miles.
Astronomical twilight 48° 33’ 55.524” S 26,570.255154469880 km or 16,509.991123383118 miles.
2017 Northern Hemisphere, summer solstice: Circumference or length:
Arctic / Antarctic Circle 66° 33’ 55.078” N / S 15,983.081 km or 9,931.426 international miles.
Civil twilight 60° 33’ 55.078” N 19,744.309 km or 12,268.545 international miles.
Nautical twilight 54° 33’ 55.078” N 23,286.284 km or 14,469.426 international miles.
Astronomical twilight 48° 33’ 55.078” N 26,570.320 km or 16,510.031 international miles.
2017 Southern Hemisphere, summer solstice: Circumference or length:
Antarctic / Arctic Circle 66° 33’ 54.374” S / N 15,983.206 km or 9,931.504 international miles.
Civil twilight 60° 33’ 54.374” S 19,744.428 km or 12,268.619 international miles.
Nautical twilight 54° 33’ 54.374” S 23,286.395 km or 14,469.495 international miles.
Astronomical twilight 48° 33’ 54.374” S 26,570.422 km or 16,510.095 international miles.
2018 Northern Hemisphere, summer solstice: Circumference or length:
Arctic / Antarctic Circle 66° 33’ 53.296” N / S 15,983.399 km or 9,931.624 international miles.
Civil Twilight 60° 33’ 53.296” N / S 19,744.611 km or 12,268.732 international miles.
Nautical Twilight 54° 33’ 53.296” N / S 23,286.566 km or 14,469.601 international miles.
Astronomical Twilight 48° 33’ 53.296” N / S 26,570.579 km or 16,510.192 international miles.
2018 Southern Hemisphere, summer solstice: Circumference or length:
Antarctic / Arctic Circle 66° 33’ 52.385” S / N 15,983.561 km or 9,931.724 international miles.
Civil twilight 60° 33’ 52.385” S 19,744.765 km or 12,268.828 international miles.
Nautical twilight 54° 33’ 52.385” S 23,286.710 km or 14,469.691 international miles.
Astronomical twilight 48° 33’ 52.385” S 26,570.712 km or 16,510.275 international miles.
2019 Northern Hemisphere, summer solstice:
Arctic / Antarctic Circle 66° 33’ 51.083” N / S
Civil twilight 60° 33’ 51.083” N
Nautical twilight 54° 33’ 51.083” N
Astronomical twilight 48° 33’ 51.083” N
2019 Southern Hemisphere, summer solstice:
Antarctic / Arctic Circle 66° 33’ 49.748” S / N
Civil twilight 60° 33’ 49.748” S
Nautical twilight 54° 33’ 49.748” S
Astronomical twilight 48° 33’ 49.748” S
2020 Northern Hemisphere, summer solstice:
Arctic / Antarctic Circle 66° 33’ 48.571” N / S
Civil twilight 60° 33’ 48.571” N
Nautical twilight 54° 33’ 48.571” N
Astronomical twilight 48° 33’ 48.571” N
2020 Southern Hemisphere, summer solstice:
Antarctic / Arctic Circle 66° 33’ 47.077” S / N
Civil twilight 60° 33’ 47.077” S
Nautical twilight 54° 33’ 47.077” S
Astronomical twilight 48° 33’ 47.077” S
Distances personally calculated, using Charles Karney's Online rhumb line calculations using the RhumbSolve utility: "RhumbSolve is accurate to about 15 nanometers (for the WGS84 ellipsoid)" or 0.000015 of a millimetre/millimeter or 0.00000059 of an inch. In emails to me from Charles Karney: "The accuracy of 15 nanometers that I quote is for paths up to half-way round the earth." "The accuracy for the Airy" [1830] "ellipsoid will be (very nearly) the same as for the WGS84 ellipsoid because the parameters are roughly the same." On RhumbSolve online: "RhumbSolve performs rhumb line calculations". "The path with a constant heading between two points on the ellipsoid at (lat1, lon1) and (lat2, lon2) is called the rhumb line (or loxodrome)". "NOTE: the rhumb line is not the shortest path between two points; that is the geodesic and it is calculated by GeodSolve."
See also: http://www.gandraxa.com/length_of_day.xml
