India has three distinct seasons: Summer, Winter and the Monsoons.

Summer

Summer is India's hottest season. Summer season starts in March with day times temperatures exceeding 30°C (86°F). Coastal India as well as the southern states of Tamil Nadu and Kerala experience high humidity. By May, most of interior India experience highs in excess 40°C (104°F). Coastal India the temperature hovers around 36°C (96.8°F), but it is extremely humid here. The land gets parched and many people die due to the high heat. Only the Himalayan and Nilgiri hill stations offer some respite from the heat with a temperate high of 25°C (77°F). North eastern India however, has a much milder climate rarely exceeding 32°C (89.6°F).

Monsoons

The monsoons come as a relief from the heat and parched landscape. The rains bring down the temperature, and make the surroundings lush and green. It is the best season to go hiking and trekking. The monsoons are intricately linked to the economy as a good monsoon results in a booming economy. The rains fill the ground water tables and reinvigorate rivers and lakes.

Southwest Monsoons

The southwest monsoons supplies over 80% of India's annual rainfall. It consists of two arms, the Bay of Bengal arm, and the Arabian Sea arm. Both arms are attracted to the low pressure area over the Thar desert in Rajasthan.

The monsoon makes its presence felt by the end of May. It starts around the 29 May, hitting the Andaman and Nicobar Islands in the Bay of Bengal. It strikes the mainland of Kerala on 1 June. By 9 June, it makes hits Mumbai, and Delhi by 29 June. The Bay of Bengal moves in a northwest direction whereas the Arabian Sea arm moves in a north by northeast direction. By first week of July, the entire country experiences rain. Predictably, southern India receives more rainfall than northern India.

During this season, cyclones occur, causing widespread devastation to coastal regions. Cherapunji , Meghalaya, the world's wettest place, received 2.647 m of rainfall. The monsoons start withdrawing by the last week of August. By mid September, it has withdrawn from Mumbai and by October, the southwest monsoons have completely withdrawn from India.

Northeast Monsoons

After the withdrawal of the monsoons, the northeast monsoons begin by November. Supplying 20% of India rainfall it doesn't cover the entire country but only the states of Tamil Nadu, West Bengal, Arunachal Pradesh, Karnataka and Meghalaya. Cold mountain air travelling along the Brahmaputra river brings rain to the northeast region of India. This picks up moisture over the Bay of Bengal resulting in heavy rain in southern India.

Winter

There isn't a "true" winter season in India. Regions lying above the Tropic of Cancer experience a sub-tropical climate. This is the dry season in most parts of India, and even in coastal areas. Further north, more temperate climate occurs. Snow does not fall in the plains, but the Himalayan states receive large amounts of snow, cutting off vital highway routes. The season starts by November in northern India and by December in southern India.

Northern India

Except for in the mountains, Northern India doesn't receive snow and the temperature in the plains rarely falls below freezing. Highs in Delhi range between 12° to 18°C. Night time temperatures fall to around 2 to 6°C. Further north in Punjab the lows does fall below freezing in the plains to around -6°C in Amritsar. Frost sometimes occurs, but the hallmark of the season is the notorious fog which disrupts daily life.

Northern India does receive some rainfall. The source is from the western disturbances originating in the Mediterranean Sea. These disturbances travel westwards, but unable to climb the Himalaya, they drop their rainfall and snow over northern India.

Eastern India

Eastern India has a much milder climate. It has mild days and cool nights. High's range from 17- 21°C. Nights average 9°C. The northeast rainfall brings rain to this region. Cold winds over the Brahmaputra river lower the temperatures.

Western and Central India

Western India has a mild climate. Pleasant days and cool nights are the feature here. Highs range between 21-26°C and lows between 9-12°C. Mists are a regular feature here.

Southern India

South India lacks a cool season. Interior areas can fall to about 16°C, but coastal areas are warm with highs of 30°C and lows of 21°C. The Nilgiri range is the exception where the lows can fall below freezing.

Withdrawal of Monsoons

This is not a true season as such. Many text books however, refer to this as a separate season. This season lasts between September and December depending on its location. The weather turns more dry and the grass starts to dry up. This season marks the transition from wet to dry climate in most parts of India. Highs range between 34°C and 28°C.

Autumn and Spring

Autumn and spring seasons only occur in the Himalayan states of Himachal Pradesh, Kashmir and Sikkim. These regions have a temperate season and experience 5 seasons annually.