Climates of India
1. Difference between Weather and Climate
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Weather → Daily atmospheric condition of a place (temperature, rainfall, humidity, wind, pressure).
Example: Today it is raining in Delhi. -
Climate → Average weather condition of a place over a long period (usually 30–40 years).
Example: Rajasthan has hot and dry climate.
2. Seasons in India
India traditionally recognizes six seasons (based on the Hindu calendar):
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Vasanta (Spring) – Feb–March → pleasant weather.
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Grishma (Summer) – April–May → very hot.
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Varsha (Rainy/Monsoon) – June–Sept → heavy rains.
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Sharad (Autumn) – Oct–Nov → clear skies, pleasant.
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Hemanta (Pre-winter) – Dec–Jan → cool.
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Shishir (Winter) – Dec–Feb → cold and dry.
(NCERT simplifies these into 4 major: Summer, Rainy, Autumn, Winter – but India’s monsoon season is unique and very important.)
3. Types of Climate in India
India’s diverse geography creates different climate zones:
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Alpine Climate – Himalayas (cold, snow, short summers).
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Subtropical Climate – Northern Plains (hot summers, cold winters).
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Arid Climate – Thar Desert (scanty rainfall, very hot).
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Semi-Arid Climate – Central Deccan Plateau (moderate rainfall, dry).
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Tropical Wet Climate – Western Coast and North-East (heavy rainfall, hot and humid).
4. Factors Affecting India’s Climate
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Latitude – Nearer to equator → hotter; farther → cooler.
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Eg: Chennai is hotter than Kashmir.
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Altitude (Height above sea level) – Higher → cooler.
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Eg: Shimla is cooler than Delhi though on same latitude.
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Distance from the Sea – Coastal areas have moderate climate, inland areas have extreme climate.
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Eg: Mumbai (mild), Nagpur (extreme).
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Relief / Topography – Physical features like mountains, valleys affect rainfall and temperature.
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Eg: Himalayas block cold winds from Central Asia and bring monsoon rainfall.
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Winds –
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Winds from land → sea are dry (winter monsoon).
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Winds from sea → land bring rain (summer monsoon).
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5. Local Climate Variations (Microclimates)
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Microclimate = Local climate different from surroundings.
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Eg: Shady areas cooler than open fields.
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Urban Heat Island Effect → Cities are hotter than nearby villages due to concrete, pollution, vehicles.
6. Monsoon in India
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Word ‘Monsoon’ → from Arabic Mausam meaning “season.”
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Summer Monsoon (SW Monsoon)
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June–Sept.
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Winds blow from sea to land.
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Heavy rainfall in West Coast, North-East, Ganga plains.
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Winter Monsoon (NE Monsoon)
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Oct–Feb.
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Winds blow from land to sea.
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Generally dry, but Tamil Nadu coast receives rainfall.
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Rainfall extremes:
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Mawsynram (Meghalaya) – ~11,000 mm → wettest place in the world.
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Thar Desert (Rajasthan) – very little rainfall.
7. Natural Disasters Linked to Climate
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Floods – Due to heavy rainfall; common in Assam, Bihar.
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Droughts – Due to monsoon failure; common in Rajasthan, Maharashtra.
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Cyclones – Powerful storms in Bay of Bengal/Arabian Sea; Eg: Cyclone Amphan (2020).
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Glacial Bursts – Sudden melting of glaciers; Eg: Uttarakhand (2013).
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Forest Fires – In dry hilly regions like Uttarakhand.
8. Climate and Human Life
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Agriculture: Monsoon determines crop cycles (rice, wheat, pulses).
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Economy: Drought → crop loss; good monsoon → prosperity.
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Culture: Festivals are linked to seasons (Baisakhi, Pongal, Onam, Diwali).
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Tourism: Hill stations in summer, beaches in winter.
9. Climate Change
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Definition: Long-term change in temperature and rainfall patterns.
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Causes:
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Greenhouse gases (CO₂, methane).
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Deforestation.
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Industrial pollution, vehicles.
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Effects in India:
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Rising temperatures.
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Erratic monsoon (floods/droughts).
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Melting Himalayan glaciers.
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Rising sea level in coastal states.
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10. Measures to Reduce Climate Problems
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Plant more trees (afforestation).
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Reduce use of coal and petrol, use solar/wind energy.
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Conserve water through rainwater harvesting.
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Disaster preparedness with early warning systems.
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Public awareness campaigns for eco-friendly lifestyle.