Seasons of India - The Summer or Hot Weather Season

The hot season in India begins in March and lasts until June. During this time, the sun's vertical rays fall directly over the Tropic of Cancer.

1. Temperature:

• The length of the day increases from March to May due to the apparent northward movement of the path of the sun's vertical rays. It results in an increase in solar radiation, which moves northward over South Asia's tropical areas, causing temperatures to rise.
• Temperatures in most parts of India range between 30°C and 32°C. As the heat belt moves north, the highest daytime temperatures rise. Temperatures around 48°C are not uncommon in the northwestern part of India.
• The heat is not as intense in south India as it is in north India. The cooling effect of the oceans, combined with the peninsular location of south India, keeps temperatures lower than in north India. As a result, temperatures in south India remain between 26°C and 32°C.
• The influence of the sea provides some relief from the heat in coastal areas. Because of their elevation, plateaus and hills are also relatively cool. The diurnal variation is large, particularly in the interior of the subcontinent to the west.

2. Pressure Conditions 

• The warmest area gradually shifts from the Deccan to northwest India. The subcontinent's high temperatures cause a low-pressure zone between the Thar Desert and the Chota Nagpur Plateau. The surrounding seas are cooler, resulting in high-pressure conditions in the Indian Ocean.
• By the end of May, a relatively high-pressure area forms near Cape Comorin and extends to the Arabian Sea. By June, the inland low-pressure system has intensified and is moving northward, with its center over Indu's lowlands and Baluchistan. The inflow of these winds in mid-June causes a shift in the weather toward the rainy season.

3. Storms and Rainfall 

• The hot-dry weather is marked by weak winds and dryness over the area. The low pressure over the Northern Plains draws winds from the surrounding areas and gives rise to thunderstorms with strong dusty winds. These winds cause a shower of rain mostly in Punjab, Haryana, and Uttar Pradesh.

4. Local Winds 

• A striking feature of the hot weather season is the strong and dusty winds, called loo, which blow during the day over northern and north-western India. These winds have temperatures ranging from 45°C to 50°C, which is hot enough to cause heatstroke.
• In Punjab, Haryana, and Uttar Pradesh, tornado-like dust storms occur occasionally.
• The thunderstorms accompanied by strong winds and heavy rainfall occur in Assam and West Bengal. These local winds are known as Kalbaisakhi which means 'the calamity of the month of Baisakh'.
• In Assam, these storms are known as Bardoli Chheerha. They form over the Chota Nagpur Plateau and are carried eastward by westerly winds. They bring rain to Assam, West Bengal, and Odisha. This rain is great for growing jute and rice in West Bengal and tea in Assam.
• Rainfall is caused by thunderstorms along the coasts of Kerala and Karnataka. Even the little rain they bring is beneficial to mango, tea, and coffee plants. These rains are known as mango showers because they aid in the early ripening of the mango crop. In Karnataka, they are also known as cherry blossoms.