Regional Variations in Climatic conditions of India

Regional Variations in Climatic conditions of India

Although there is an overall unity in the usual pattern of monsoon, there are some regional variations in the climatic conditions of India. The important elements of this variation are precipitation, duration of different seasons and temperature. For instance, during summer the temperature around Pahalgam of Jammu and Kashmir is around 20 degrees, whereas on the same day it is 50 degrees in Rajasthan. Similarly, in winters, the temperature is as low as minus 45 degrees in dras and as high as 20 degrees in Thiruvananthapuram. 

Temperature

Summer temperature in certain regions of the Rajasthan desert might reach 50°C, whereas Pahalgam in Jammu and Kashmir may hover around 20°C. Generally, coastal locations have fewer temperature contrasts. Seasonal differences are particularly pronounced in the country’s interior.

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Precipitation  

Precipitation occurs mostly in the form of snowfall in the Himalayan peaks, but it showers across the remaining area of the nation. Annual precipitation varies significantly between Meghalaya and Ladakh and western Rajasthan, ranging from over 400 cm in Meghalaya to less than 10 cm in Ladakh and western Rajasthan. From June through September, the majority of the nation receives rainfall.

Climatic Controls

Latitude, altitude, pressure and wind system, distance from the sea (continentally), ocean currents, and relief characteristics are the six primary climatic controls.

• Due to the curvature of the Earth, the quantity of solar energy received changes with latitude and altitude, usually lowering air pressure from the Equator to the Poles
• As one ascends from the Earth’s surface to greater altitudes, the atmosphere gets less dense and the temperature decreases. As a result, the hills are cooler in the summer
• Pressure and wind systems are affected by the area’s height and latitude, which has an effect on the temperature and rainfall pattern
• As the distance from the sea rises, the water’s moderating impact diminishes, and humans begin to encounter harsh weather, referred to as continental weather (very hot during summers and very cold during winters)
• Coastal climates are influenced by ocean currents and onshore winds
• Relief also has an effect on a location’s climate. For instance, high mountains operate as barriers against cold or hot breezes; they may also help in precipitation if they are sufficiently high and in the route of rain-bearing winds

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Factors affecting India’s Climate

1. Latitude 

• From the Rann of Kachchh in the west to Mizoram in the east, the Tropic of Cancer runs across the country’s centre
• The latitudinal extent of India is  8°4’N – 37°6’N
• India’s climate is tropical with subtropical traits

2. Altitude 

• In the north, India has Himalayan peaks (an average height of around 6,000 metres), which shield the country from the cold winds of central Asia. Due to these mountains, this subcontinent has milder winters than central Asia

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3. Pressure and Winds

• In India, the climate and accompanying weather conditions are determined by the following atmospheric factors:
  • Pressure and winds at the surface
  • Circulation of the upper air
  • Western Cyclonic disturbances and tropical cyclones
• India is located in an area characterised by northeastern trade winds

4. Unique Pressure and Wind Conditions over India

• Throughout the colder time of year, a high-pressure framework toward the north of the Himalayas exists, and chilly, dry breezes blow from this area to the low-pressure zones over the southern oceans
• During the summer, a low-pressure region forms across central Asia and northwestern India, completely reversing the direction of winds
• Southwest Monsoon winds: Air travels in a south-easterly direction from the high-pressure region over the southern Indian Ocean, crosses the equator, and turns right towards the Indian subcontinent’s low-pressure zones. These winds sweep across warm waters, accumulating moisture and bringing extensive rainfall to India’s landmass
• The strongest impact of Coriolis force is felt on the weather which is affected by the rotation of the earth. The Coriolis force makes storms swirl anti-clockwise in the northern hemisphere and clockwise in the southern hemisphere
• Upper air circulation: It is dominated by a westerly flow. The jet stream is a critical component of this movement

• These are situated between 27° and 30° north latitude, and so are referred to as subtropical westerly jet streams. Throughout the year, save during the summer, these jet streams blow south of the Himalayas across India. Western cyclonic disturbances occurring in the country’s north and north-western regions are a result of these westerly winds
• In summer, the subtropical westerly jet stream follows the apparent movement of the Sun north of the Himalayas
• During the summer months, an easterly jet stream known as the subtropical easterly jet stream sweeps across peninsular India at roughly 14°N

5. Jet Stream

• Jet streams are a small band of westerly winds at a high altitude (over 12,000 m) in the troposphere
• Jet stream top speed ranges from around 110 km/h in the summer to approximately 184 km/h in the winter
• Several distinct jet streams have been found. The mid-latitude and subtropical jet streams are the most consistent

Conclusion  

Briefly put, the climatic conditions of southern India are a bit different from the northern parts of India due to temperature and rainfall. The range of temperature increases as we move away from coastal areas to interior parts of the country. Resultantly, the people living around Konkan and Malabar coasts do not experience extreme temperatures whereas people residing in north-western parts of India experience sharp rises in temperatures. Likewise, the distribution in rainfall is equally striking.