Wanderlust World Wanderlust World The **Tropic of Cancer (23°26′N)** is the northernmost latitude where the sun reaches zenith (90° altitude) at solar noon — on the summer solstice (~June 21). Locations **on** the Tropic get it once/year; locations **between** the Equator and the Tropic get it **twice/year** (when sun's declination matches their latitude on its way north and south).
Ahmedabad: 23°01′N — just 25′ south of the Tropic. The sun's declination crosses 23°01′N **twice**: ~May 20 (northbound) and ~July 23 (southbound). On those dates, solar noon = zenith. Correction: The source claiming winter solstice is wrong — the sun is at 23°26′S then, far from Ahmedabad.
Kolkata: 22°34′N — 52′ south of the Tropic. The sun's maximum declination is 23°26′N. Kolkata's latitude is **never reached** by the subsolar point. Maximum noon altitude = 89°08′ (summer solstice). **Not overhead.**
Delhi: 28°41′N — far north of the Tropic. Sun's declination never exceeds 23°26′N. Maximum noon altitude = 90° – (28°41′ – 23°26′) = **84°45′**. Never overhead.
Cities **between Equator and Tropic of Cancer**: Thiruvananthapuram (8°31′N), Chennai (13°05′N), Mumbai (19°04′N), Hyderabad (17°23′N), Bengaluru (12°58′N), Visakhapatnam (17°42′N), Bhubaneswar (20°18′N) — **all get zenith sun twice/year**.
| City | Latitude | Zenith Sun? | Frequency |
|---|---|---|---|
| Ahmedabad | 23°01′N | Yes (barely) | Twice (May 20, Jul 23) |
| Kolkata | 22°34′N | **No** | Never |
| Delhi | 28°41′N | No | Never |
| Mumbai | 19°04′N | Yes | Twice |
| Chennai | 13°05′N | Yes | Twice |
Many Indian textbooks oversimplify: "Tropic of Cancer passes through India → places near it get overhead sun." They don't distinguish "on the line" (once) vs. "south of the line" (twice) vs. "north of the line" (never). Kolkata is south but *too far south* — the sun never reaches its latitude at zenith.