According to traditional Indian culture the Indian subcontinent undergoes six seasons, with the approximate duration of each being two months. These are as follows – spring, summer, monsoons, early autumn, late autumn & winter. But according to the modern climatic studies India has only three predominant seasons they are summer season, rainy season and winter season. The summer months lasts from about March to June, the rainy season stretches from June to October and the winter season remains in India from November to March. Various climatic factors are responsible for the seasonal changes in India.
The monsoon season is pretty fervent in India with heavy clouds drenching most parts of India. The summer season is pretty hectic too with India being a tropical country most parts of India are scorched with sweltering heat. The Indian winter is usually mild and enjoyable in comparison to the other temperate countries of the world.
The India Meteorological Department (IMD) designates four official seasons:
Once the monsoons subside, average temperatures gradually fall across India. As the Sun’s vertical rays move south of the equator, most of the country experiences moderately cool weather; temperatures change by about 0.6°C (1.08°F) per degree of latitude. December and January are the coldest months, with mean temperatures of 10 – 15°C (50 – 59°F) in Indian Himalayas. Mean temperatures are higher in the east and south, where they reach 20 – 25°C (68 – 77°F).
In northwestern India, virtually cloudless conditions prevail in October and November, resulting in wide diurnal temperature swings; as in much of the Deccan Plateau, they range between 16°C (28.8°F) – 20°C (36.0°F). However, from March to May, “western disturbances” bring heavy bursts of rain and snow. These extra-tropical low-pressure systems originate in the eastern Mediterranean Sea.
They are carried towards India by the subtropical westerlies, which are the prevailing winds blowing at North India’s range of latitude. Once their passage is hindered by the Himalayas, they are unable to proceed further, and they release significant precipitation over the southern Himalayas. The three Himalayan states (Jammu and Kashmir in the extreme north, Himachal Pradesh, and Uttarakhand) experience heavy snowfall; in Jammu and Kashmir, blizzards occur regularly, disrupting travel and other activities.
The rest of North India, including the Indo-Gangetic Plain, almost never receives snow. However, in the plains, temperatures occasionally fall below freezing, though never for more one or two days. Winter highs in Delhi range from 16°C (61°F) to 21°C (70°F). Nighttime temperatures average 2-8°C (36-46°F). In the Punjab plains, lows can fall below freezing, dropping to around “6°C (21°F) in Amritsar. Frost sometimes occurs, but the hallmark of the season is the notorious fog, which frequently disrupts daily life; fog grows thick enough to hinder visibility and disrupt air travel 15–20 days annually.
Eastern India’s climate is much milder, experiencing moderately warm days and cool nights. Highs range from 23°C (73°F) in Patna to 26°C (79°F) in Kolkata (Calcutta); lows average from 8°C (46°F) in Patna to 14°C (57°F) in Kolkata. Frigid winds from the Himalayas can depress temperatures near the Brahmaputra River. The two Himalayan states in the east, Sikkim and Arunachal Pradesh, receive substantial snowfall. The extreme north of West Bengal, centred around Darjeeling, also experiences snowfall, but only rarely.
In South India, particularly the hinterland of Maharashtra, Madhya Pradesh, parts of Karnataka, and Andhra Pradesh, somewhat cooler weather prevails. Minimum temperatures in western Maharashtra, Madhya Pradesh and Chhattisgarh hover around 10°C (50°F); in the southern Deccan Plateau, they reach 16°C (61°F).
Coastal areas, especially those near the Coromandel Coast, and low- elevation interior tracts are warm, with daily high temperatures of 30°C (86°F) and lows of around 21°C (70°F). The Western Ghats, including the Nilgiri Range, are exceptional; there, lows can fall below freezing. This compares with a range of 12°C (21.6°F) – 14°C (25.2°F) on the Malabar Coast; there, as is the case for other coastal areas, the Indian Ocean exerts a strong moderating influence on weather.