Climate of India (Hot Weather Season)

INTRODUCTION

Climate refers to the total of weather conditions and variations over a large area for a long period. Weather refers to the state of the atmosphere over an area for a shorter period. The elements of the weather and the climate are the same i.e. temperature, atmospheric pressure, wind, humidity, and precipitation. The Weather conditions fluctuate very often even within a day. But, there is some common pattern over a few weeks or months i.e. days are cool or hot, windy or calm, cloudy or bright, and wet or dry.

The climate of India is described as a ‘Monsoon’ type. In Asia, this type of climate is found mainly in the South and South-East. Despite, an overall unity in the general pattern, there are clear and distinct regional variations in the climatic conditions within the country. It varies from the very cold conditions of the Northern Himalayan belt to the hot climate of the Rajasthan desert to the moderate climate of the coastal areas.

Seasons of India  

The climate of India is characterized by distinct personality. The weather conditions change from one season to another. These changes are particularly noticeable in the interior parts of the country, particularly in the Northern, North-Western, and North-Eastern parts of the country. The coastal areas do not experience much temperature variation, though rainfall has a distinct pattern.

The Hot Weather Season 

Due to the apparent movement of the Sun, the global heat belt shifts Northward. As such, the weather starts progressively changing during February-March from South to North.  Temperature starts rising during this period. In March, maximum day temperature generally exceeds 35ºC in areas South of the Vindhyas.

In April, the maximum day temperature exceeds 37°C in the Northern plains of India. By mid-May, the temperature touch 41°C to 48ºC to 48ºC in many parts of the country, especially in the North-West plains and Central India. Even the minimum temperature does not go below 20°C. As a result, the night also becomes quite hot.

In peninsular India, these temperatures reveal the moderating influence of the ocean ( 38° in the Deccan plateau). But this year in May 2024, the temperature exceeds  50ºC in some parts of the country. The summer months experience rising temperatures and falling air pressure in the Northern part of the country. Towards the end of May, an elongated low-pressure area develops in the region, extending from the Thar desert in the southwest, the dry and hot winds blow in the afternoon and very often they continue even up to midnight. They often blow in large parts of Ganga plains and are locally called loo.

Towards the close of the summer season, pre-monsoon showers are a common phenomenon in Kerala and Karnataka, They help in the early ripening of Mangoes and hence are called locally Mango Showers. An advance of the pre-monsoon showers and early advance of monsoons, further North is checked by a belt of relatively high air pressure lying over the Deccan plateau.

Natural and Anthropogenic factors behind rising temperature in India Climate of India (Hot Weather Season)

The rising temperature in India is primarily due to the combination of natural and anthropogenic (human-induced) factors. Here are the main reasons:

a) Greenhouse Gas Emissions

• Fossil Fuel Combustion: The burning of coal, oil, and natural gas for energy and transportation releases large amounts of carbon dioxide (CO2) and other greenhouse gases (GHGs), trapping heat in the atmosphere.
• Industrial Activities: Industrial processes emit GHGs including CO2, methane, and nitrous oxide, which contribute to global warming.

b) Urban Heat Island Effect

•  Urbanization: Rapid urbanization leads to the development of cities with extensive concrete, asphalt, and buildings that absorb and retain heat, causing higher temperatures in urban areas compared to rural surroundings.
• Reduced Vegetation: The loss of green spaces and vegetation in cities reduces the natural cooling effects provided by plants and trees.

c) Deforestation and Land Use Changes

• Loss of Forests: Deforestation for agriculture, urban development, and infrastructure projects reduces the number of trees that absorb CO2 and provide shade, contributing to higher temperatures.
• Agricultural Practices: Certain agricultural activities, like rice farming and livestock production, emit methane, a potent greenhouse gas.

d) Climate Change

• Global Warming: The increase in global temperatures due to elevated levels of GHGs is leading to more frequent and intense heat waves in India.
• Changes in Weather Patterns: Climate change is altering monsoon patterns, often leading to prolonged periods of high temperatures before the onset of monsoon rains.

e) Geographical Factors

• Location: India’s geographical position near the equator means it receives high solar radiation, contributing to high baseline temperatures.
• Topography: The varied topography, including vast plains and deserts, can influence local climatic conditions, leading to extremely high temperatures in some regions, such as the Thar desert.

f) Population Density

• High Population Density: High population density in urban areas increases energy consumption, waste generation, and heat production, further contributing to local warming.

g) Water Bodies and Evaporation

• Decline in Water Bodies: Reduction in the number of lakes, rivers, and other water bodies due to urbanization and climate change reduces evaporative cooling.
• Drought Conditions: Frequent droughts decrease soil moisture and water availability. leading to higher land surface temperatures.

h) Air Pollution

• Aerosols and Particulate Matter: Air pollution from vehicles, industries, and biomass burning can trap heat and influence local and regional climate conditions.

Addressing the issue of excessive heat in India requires a multifaceted approach, including reducing GHG emissions, increasing urban green spaces promoting sustainable land use practices, and improving infrastructure to better cope with extreme temperatures.