Tropic of Cancer Map
The Tropic of Cancer (23.4394° N) is the farthest north the Sun's direct rays ever reach. Trace it across three continents, meet the 17 countries it crosses, and learn why the Sahara and Arabian deserts lie exactly here.
The 17 countries on the Tropic of Cancer
West to east. (The line also passes through Western Sahara, a disputed territory.)
- 1Mexico — Crosses the Baja California peninsula and the mainland; Cabo San Lucas sits just south of the line.
- 2Bahamas — Passes through the Exuma island chain in the western Atlantic.
- 3Mauritania — Runs through the Sahara, one of the hottest stretches of the entire parallel.
- 4Mali — Crosses the northern Sahara regions of the country.
- 5Algeria — A long Saharan crossing — the tropic passes well south of Algiers.
- 6Niger — Through the Ténéré desert, among the most remote terrain on the line.
- 7Libya — Crosses the Libyan Sahara south of the coastal cities.
- 8Chad — Through the northern desert regions near the Tibesti mountains.
- 9Egypt — Passes just south of Aswan; ancient Egyptians noted the overhead Sun here at the solstice.
- 10Saudi Arabia — Crosses the central Arabian Peninsula, including near Riyadh.
- 11United Arab Emirates — A short crossing through the desert emirates south of Abu Dhabi.
- 12Oman — Through the interior desert and the edge of the Empty Quarter.
- 13India — Crosses eight states from Gujarat to West Bengal; Ujjain's ancient observatory tracked it.
- 14Bangladesh — A brief crossing in the west of the country.
- 15Myanmar — Through the central dry zone of the country.
- 16China — Crosses Yunnan, Guangxi and Guangdong; the Tropic of Cancer Tower marks it in Guangzhou.
- 17Taiwan — Passes through Chiayi county, marked by the Tropic of Cancer Monument.
The June solstice line
The Tropic of Cancer marks the farthest north the Sun's direct rays ever reach — on the June solstice (around June 21), the Sun stands directly overhead at noon everywhere along this parallel, and the Northern Hemisphere gets its longest day of the year. North of this line the Sun is never directly overhead; that is the astronomical definition of the temperate zone.
The name is a 2,000-year-old fossil: when it was named, the June-solstice Sun appeared in the constellation Cancer. Because of the slow wobble of Earth's axis (precession), the solstice Sun now stands in Taurus — but the name stuck. The latitude itself also drifts: it is currently about 23.44° and shrinking by roughly 0.47 arcseconds per year as Earth's axial tilt slowly decreases.
Look at a map and a pattern jumps out: the world's great northern deserts — the Sahara, the Arabian, the Thar — all cluster along this line. That is no coincidence. Air rising at the equator travels poleward, cools and sinks back down around 20–30° latitude, creating permanent high-pressure belts of dry, descending air. The Tropic of Cancer runs straight through the heart of that subtropical desert belt.
How to use this tool
Follow the orange line from Mexico across North Africa, Arabia, India and China to Taiwan.
All 17 crossings are listed west to east with a note on what the line passes near in each.
The sections explain the June solstice, the 2,000-year-old name, and the subtropical desert belt.
What people use this tool for
See the astronomical boundary of the tropics — north of here the Sun is never directly overhead.
Connect the Sahara, Arabian and Thar deserts to the sinking-air mechanism on one map.
Find where the Sun stands overhead at noon on June 21.
How it's calculated
The tropic's latitude equals Earth's current axial tilt (obliquity), about 23.4394°, which varies slowly over a 41,000-year cycle. The line is the parallel where the Sun reaches the zenith at local noon on the June solstice. Country crossings follow current international boundaries; the disputed Western Sahara is noted separately rather than counted.
Related tools and resources
Frequently asked questions
What is the Tropic of Cancer?
The parallel at about 23.44° N marking the northernmost latitude where the Sun can be directly overhead — reached on the June solstice.
Why is it called the Tropic of Cancer?
Two thousand years ago the June-solstice Sun appeared in the constellation Cancer. Precession has since moved it into Taurus, but the name stuck.
Is the latitude exactly 23.5°?
Not quite — it is currently about 23.4394° and drifts as Earth's axial tilt slowly changes, by roughly 15 metres per year.
Which countries does it cross?
Seventeen: Mexico, Bahamas, Mauritania, Mali, Algeria, Niger, Libya, Chad, Egypt, Saudi Arabia, UAE, Oman, India, Bangladesh, Myanmar, China and Taiwan.
Why are there so many deserts on this line?
Air rising at the equator sinks back down around 20–30° latitude, creating permanent high-pressure belts of dry descending air — the subtropical desert belt.
What is the difference between the Tropic of Cancer and the equator?
The equator (0°) gets the overhead Sun at the equinoxes; the Tropic of Cancer (23.44° N) gets it once a year, at the June solstice.