FACTORS BEHIND INDIA’S CLIMATE
- Latitude: Northern part of India lies in sub-tropical and temperate climate zone (being away from the equator, experiences extreme climate with high daily and annual range of temperature.) and the part lying south of the Tropic of Cancer experiences high temperatures throughout the year with small daily and annual range.
- Himalayan Mountains function as shield to protect the subcontinent from the cold northern winds. The Himalayas also trap the monsoon winds, forcing them to shed their moisture within the subcontinent.
- Distribution of Land and Water: Differential heating of land and sea creates different air pressure zones in different seasons in and around the Indian subcontinent. Difference in air pressure causes reversal in the direction of monsoon winds.
- Distance from the Sea: Areas in interior of India are far away from the moderating influence of the sea. Such areas have extremes of climate.
- Altitude: Due to thin air, places in the mountains are cooler than places on the plains.
- Relief: Windward sides of Western Ghats and Assam receive high rainfall during June-September whereas the southern plateau remains dry due to its leeward situation along the Western Ghats.
Inter regional variations in India’s climate:
Spatial variation: Southern India has relatively moderate climate as compared to Northern India. On one hand the peaks of Himalayas experience one of the coldest climates (region is also known as third pole) and on the other, Islands of Andaman and Nicobar experiences Hot humid climate throughout the year. Rajasthan experience less then 50cm of average annual rainfall and thus has Arid and semi-arid conditions but Meghalaya (Cherrapunji and Mawsynram) are the wettest places of the world experiencing more than 1000 cm of rainfall. Similarly, While in the summer the mercury occasionally touches 55°C in the western Rajasthan, it drops down to as low as minus 45°C in winter around Leh.
Temporal variation: Ganga delta and coastal plains of Orissa are hit by heavy rain-bearing storms almost every third or fifth day in July and August while the Coromandal coast, a thousand km to the south, goes generally dry during these months. Most parts of the country get rainfall during June-September, but on the coastal areas of Tamil Nadu, it rains in the beginning of the winter season.
In general, Indian climate is monsoonal in nature. Primarily there are four seasons in India.
- Summer season
- Southwest Monsoon season
- Retreating monsoon season
- Winter season
