- Latitude – Southern India is warmer as it lies in the tropical zone; northern India lies in the temperate zone.
- Altitude – Temperature decreases with height; hills are cooler than plains.
- Distance from Sea – Coastal areas have moderate climate; interior areas have extreme climate.
- Himalayas – Block cold winds and cause rainfall by stopping monsoon winds.
- Monsoon & El Niño – Monsoon controls rainfall; El Niño weakens monsoon, La Niña strengthens it.
Key Points
Key Points: Factors Affecting India's Climate
Key Points: Seasons in India > Hot Dry Summer
- Hot dry summer season lasts from March to May due to the sun’s vertical rays moving towards the Tropic of Cancer.
- High temperatures occur in interior India, while coastal and hilly areas are cooler.
- Low pressure develops over north and northwest India; seas have high pressure.
- Local winds like Loo and Kalbaisakhi blow during this season.
- Pre-monsoon showers (Mango/Blossom showers) help crops like tea, coffee, rice, and mango.
Key Points: Seasons in India > The South-West Monsoon Season
- South-West Monsoon season lasts from June to September and is the main rainy season of India.
- It is caused by differential heating of land and sea, creating low pressure over north-west India and high pressure over surrounding seas.
- South-East Trade Winds, after crossing the Equator, are deflected by the Coriolis force and blow as South-West Monsoon winds.
- These winds divide into two branches due to India’s peninsular shape: Arabian Sea branch and Bay of Bengal branch.
- The monsoon brings heavy, uneven rainfall, with orographic rain on windward slopes, while Tamil Nadu and western Rajasthan receive little rainfall.
Key Points: Seasons in India > Retreating Monsoon
- Retreating Monsoon season occurs during October and November due to the weakening of the low-pressure trough over the Ganga plains.
- The retreat of monsoon is caused by the southward movement of the sun, leading to high pressure replacing low pressure over northern India.
- Clear skies, high humidity, and high temperature cause uncomfortable weather called ‘October Heat’.
- Cyclonic depressions form over the Bay of Bengal and Andaman Sea, bringing heavy rainfall to Tamil Nadu, Odisha, and coastal Karnataka.
- Interior Deccan remains dry due to the rain-shadow effect of the Eastern Ghats, while the Coromandel Coast receives most of its rainfall.
Concepts [10]
- Introduction to Climate
- Unity and Diversity in the Monsoon Climate
- Factors Affecting India's Climate
- Indian Monsoonal Regime
- The Rhythm of Seasons
- The Cold Weather Season
- Seasons in India > Hot Dry Summer
- Seasons in India > The South-West Monsoon Season
- Seasons in India > Retreating Monsoon
- Traditional Indian Seasons
