Latitudinal and longitudinal extent: where India lies on the globe

Detail

1. Key terms

• Latitude: how far a place is north or south of the Equator (0°), measured in degrees. Lines of latitude are called parallels because they run side by side and never meet.
• Longitude: how far a place is east or west of the Prime Meridian (0°, Greenwich, London). Lines of longitude are called meridians. They run from pole to pole and meet at both poles.
• Latitudinal extent: the spread of a country between its southernmost and northernmost parallels. Longitudinal extent: the spread between its westernmost and easternmost meridians.
• Mainland: the main, continuous landmass of a country. It does not include its islands.

2. Where India lies on the globe

• India lies wholly in the Northern Hemisphere (north of the Equator) and the Eastern Hemisphere (east of Greenwich).
• Mainland extent:

Extent	From	To	Spread
Latitudinal	8°4'N (Kanniyakumari)	37°6'N (northern tip of Jammu and Kashmir/Ladakh, as claimed by India)	about 29° (≈30°)
Longitudinal	68°7'E (Gujarat)	97°25'E (Arunachal Pradesh)	about 29°18' (≈30°)

• The mainland runs from Kashmir to Kanniyakumari (north to south) and from Arunachal Pradesh to Gujarat (east to west).
• Prelims trap: 8°4'N–37°6'N is the extent of the mainland only. The whole territory reaches further south, to 6°45'N at Indira Point.

3. Indira Point: southern limit of Indian territory

• Location: 6°45'N, at the southern tip of Great Nicobar Island, Andaman and Nicobar Islands (UT), in the Bay of Bengal. It is the southernmost point of India's territory [2].
• It sits beside the Great Channel, also called the Six Degree Channel. This is a busy international shipping lane [2].
• The Six Degree Channel is the strait that separates Great Nicobar (India) from Sumatra (Indonesia).

• Indira Point is about 150 km from Indonesian territory. This makes Indonesia India's nearest maritime neighbour in the south-east.

• 2004 tsunami: a magnitude 9.1 earthquake hit off Sumatra (Indonesia) on 26 December 2004 [3]. The tsunami it caused hit the Andaman and Nicobar Islands hard [3]. Part of Indira Point went under the sea.

• A tsunami is a series of very long sea waves. It is started by a sudden movement of the sea floor, usually an undersea earthquake.
• Cause → process → result: the sea floor near Sumatra moved → huge waves spread across the Bay of Bengal → the coast of Great Nicobar sank and was flooded → part of Indira Point was permanently lost to the sea.

4. Extreme points of India

Direction	Point	Where	Note
North	Indira Col	Siachen Glacier area, Ladakh	As claimed by India; it is a mountain pass (col) on the Karakoram ridge
South (whole territory)	Indira Point	Great Nicobar, Andaman and Nicobar Islands	6°45'N [2]
South (mainland)	Kanniyakumari (Cape Comorin)	Tamil Nadu	8°4'N; the Arabian Sea, Bay of Bengal and Indian Ocean meet here
East	Kibithu	Anjaw district, Arunachal Pradesh	Near the trijunction with China and Myanmar
West	Guhar Moti	Kachchh district, Gujarat	Near Sir Creek, close to the border with Pakistan

• Order to remember: north is in Ladakh, south is in Andaman and Nicobar (or Tamil Nadu for the mainland), east is in Arunachal Pradesh, west is in Gujarat.

5. Why the two "30 degrees" are not equal in kilometres

• The fact: both spreads are about 30°. But the north-south distance is 3,214 km, while the east-west distance is only 2,933 km.
• Why this happens:
• Parallels are evenly spaced. So 1° of latitude ≈ 111 km everywhere on Earth.
• Meridians come together as you go towards the poles, and they meet at the poles. So the distance covered by 1° of longitude shrinks as latitude increases. It is about 111 km at the Equator and 0 km at the poles.

• Rule of thumb: length of 1° of longitude ≈ 111 km × cos(latitude).

• Worked figures for India:

Latitude	Place (approx.)	1° of longitude ≈
0°	Equator	111 km
~8°N	Kanniyakumari	110 km
~23.5°N	Tropic of Cancer	102 km (111 × 0.917)
~37°N	Northern tip	89 km

• Result: India's east-west extent lies mostly between about 20°N and 28°N, where a degree of longitude is shorter than 111 km. So the east-west distance comes out smaller than the north-south distance, even though both spreads are about 30°.

6. Longitude and time

• The Earth turns through 360° in 24 hours, so 1° of longitude = 4 minutes of time.
• India's longitudinal spread is about 29°18'. That is about 2 hours of difference in local time between Arunachal Pradesh and Gujarat.

• In Parliament, it has been noted that the sun rises nearly two hours earlier in the east than at India's western tip [4].

• Indian Standard Time (IST) is fixed on the 82°30'E meridian, which passes through Mirzapur (Uttar Pradesh) [5]. IST is 5 hours 30 minutes ahead of GMT.

• The Legal Metrology (Indian Standard Time) Rules, 2026 were notified to make IST the single, legally binding time reference across India ("One Nation, One Time") [6].

7. Tropic of Cancer: the line that divides India in two

• Definition: the Tropic of Cancer (23°30'N) is the northernmost parallel where the noon sun can be directly overhead. This happens around 21 June, the summer solstice (the day the sun reaches its farthest point north).
• It passes through roughly the middle of India. It crosses 8 states, from west to east:

#	State	Nearby map cue
1	Gujarat	Gandhinagar lies just north of it
2	Rajasthan	Southern part (near Banswara)
3	Madhya Pradesh	Bhopal lies just north of it
4	Chhattisgarh	Northern part
5	Jharkhand	Ranchi lies just south of it
6	West Bengal	Near Krishnanagar
7	Tripura	Agartala lies just north of it
8	Mizoram	Aizawl lies just north of it

• Mnemonic (west to east): Good Rain Makes Crops Jump With True Magic (Gujarat, Rajasthan, MP, Chhattisgarh, Jharkhand, West Bengal, Tripura, Mizoram).
• States it does NOT cross (common trap): Odisha, Bihar, Uttar Pradesh, Maharashtra, Assam, Meghalaya, Manipur.

8. Effect of the Tropic of Cancer on landforms, climate, soils and vegetation

• South of 23°30'N lies in the tropical zone (the belt between the two tropics, where the noon sun is overhead at least once a year).
• North of 23°30'N lies in the sub-tropical or warm temperate zone.
• Cause → result chain:
• The angle of the sun changes with latitude. In the south, the noon sun is high all year, so it is hot throughout and the yearly temperature range is small.
• The north gets slanting sun in winter. This gives cold winters, a large yearly temperature range and even snow in the Himalaya.

• Result: big differences in climate, soils (for example, deeply weathered laterite soils in the hot, wet south), natural vegetation (tropical evergreen forests in the south compared with temperate and alpine forests in the north) and landforms.

• Distance from the sea adds to this. Coastal and peninsular areas have a mild maritime climate. The interior of the north has a harsh continental climate (very hot summers and cold winters, because land heats and cools fast).

9. India's frame in numbers (supporting data)

• Land border: 15,106.7 km in total. Bangladesh 4,096.7 km, China 3,488 km, Pakistan 3,323 km, Nepal 1,751 km, Myanmar 1,643 km, Bhutan 699 km, Afghanistan 106 km (MHA data) [7].
• Coastline: the old figure of 7,516.6 km has been reassessed to 11,098.81 km by the National Hydrographic Office (NHO) with the Survey of India. The new figure uses GIS software and high-resolution High-Water Line data (NCERT: 7,516.6 km including islands) [8][9].
• The increase comes from mapping the coast's many small bends at a finer scale. The coast itself has not grown.

Prelims Hooks

• 8°4'N–37°6'N and 68°7'E–97°25'E is the mainland extent. The whole territory reaches 6°45'N at Indira Point.
• Indira Point: Great Nicobar (Andaman and Nicobar Islands). It is on the Six Degree Channel, faces Sumatra (Indonesia) and was partly submerged in the 2004 tsunami.
• Extreme points: north, Indira Col (Ladakh); east, Kibithu (Anjaw, Arunachal Pradesh); west, Guhar Moti (Kachchh, Gujarat); south mainland, Kanniyakumari (Tamil Nadu).
• N-S distance 3,214 km is greater than E-W distance 2,933 km, although both spreads are about 30°. The reason is that meridians converge towards the poles.
• 1° of latitude ≈ 111 km everywhere. 1° of longitude ≈ 102 km at 23.5°N.
• Tropic of Cancer crosses 8 states, west to east: Gujarat, Rajasthan, MP, Chhattisgarh, Jharkhand, West Bengal, Tripura, Mizoram. It does not cross Odisha or Bihar.
• State capitals close to the Tropic of Cancer: Gandhinagar, Bhopal, Ranchi, Agartala, Aizawl.
• About 30° of longitude × 4 minutes ≈ 2 hours of local time difference. IST is based on 82°30'E (Mirzapur, Uttar Pradesh) [5].
• Coastline reassessed: 7,516.6 km → 11,098.81 km (NHO and Survey of India) [8].

Mains Points

• Latitude shapes diversity: the Tropic of Cancer splits India into a tropical south and a sub-tropical/warm-temperate north. Together with the Himalaya and distance from the sea, this explains India's range of climates, soils, forests and crops (GS-I).
• Longitudinal spread and time: about 2 hours of solar time separate Arunachal Pradesh from Gujarat [4]. This creates the debate over a separate time zone for the North-East (early sunrise, lost daylight hours, energy use). The IST Rules, 2026 take the single-time-zone, "One Nation, One Time" approach [6] (GS-I/GS-III).
• Strategic southern tip: Indira Point overlooks the Six Degree Channel, a major international shipping lane [2]. This makes Great Nicobar important for maritime security and port development. Its exposure to tsunamis (2004) shows the disaster risk on this frontier [3] (GS-III).
• Finer mapping changes national figures: the coastline reassessment (7,516.6 → 11,098.81 km) [8] matters for coastal zone management, maritime boundaries and disaster planning. It shows the value of modern geospatial survey (GS-I maps, GS-III).