Divide India into climatic zones according to Koppen and Thornthwaite.

Introduction: India exhibits extraordinary bio-climatic diversity. Wladimir Köppen (empirical scheme based on monthly temperature, rainfall, and vegetation) and C.W. Thornthwaite (rational scheme based on precipitation effectiveness and thermal efficiency) formulated comprehensive climatic demarcations of India.

1. Climatic Classification of India by Wladimir Köppen:

• 1. Amw (Tropical Monsoon with Short Dry Season): Western Coastal Plains of India (Malabar/Konkan) and Tripura ($>200 ext{ cm}$ rainfall).
• 2. As (Tropical Wet with Summer Dry Season): Coromandel Coast of Tamil Nadu (receives winter rainfall from retreating NE monsoon).
• 3. Aw (Tropical Savanna Climate): Peninsular Plateau south of the Tropic of Cancer (excluding Coromandel/Western Ghats).
• 4. BShw (Semi-Arid Steppe Climate): Rain-shadow belt of Western Ghats (Karnataka, interior Maharashtra), parts of Gujarat, and south-west Punjab/Haryana.
• 5. BWhw (Hot Desert Climate): Extreme western Rajasthan (Thar Desert - $<20 ext{ cm}$ rain).
• 6. Cwg (Monsoon with Dry Winter - Gangetic Type): Northern Plains of India, Ganga-Brahmaputra basin, and Malwa/Bundelkhand.
• 7. Dfc (Cold Humid Winter with Short Summer): Arunachal Pradesh and eastern Himalayas.
• 8. E / ET (Tundra / Polar / Highland Climate): High Himalayan ranges of Jammu & Kashmir, Ladakh, Himachal, and Uttarakhand.

2. Climatic Classification of India by C.W. Thornthwaite:

• Based on Precipitation Effectiveness (P-E Index) and Thermal Efficiency (T-E Index):
  • A (Perhumid / Wet): Western Ghats and North-East hills ($P ext{-}E ge 128$).
  • B (Humid): Foothills of Himalayas, Bengal, and Assam ($P ext{-}E: 64 ext{–}127$).
  • C (Sub-humid): Indo-Gangetic Plains and Central Peninsular India ($P ext{-}E: 32 ext{–}63$).
  • D (Semi-Arid): Rain-shadow Deccan, Western Haryana, and Rajasthan fringes ($P ext{-}E: 16 ext{–}31$).
  • E (Arid): Thar Desert of Western Rajasthan ($P ext{-}E < 16$).

Conclusion: Köppen's scheme remains the most practically applied classification for agrarian and geographical mapping in India.