India has a diverse climate due to its vast size and geographical features. The country experiences rainfall during different months in different regions. However, most parts of India receive rainfall during the months of June to September.

Monsoon Season:

- Monsoon season in India is characterized by the arrival of the southwest monsoon winds, which bring heavy rainfall to the country.
- The monsoon season officially starts in June and continues until September.
- During this period, moist winds from the Indian Ocean and the Arabian Sea move towards the Indian subcontinent, resulting in widespread rainfall across the country.
- The southwest monsoon is a crucial phenomenon for Indian agriculture as it provides the majority of the country's annual rainfall, essential for the growth of crops.

Reasons for Monsoon Season:

- The monsoon season occurs due to the differential heating and cooling of land and sea.
- In summer, the landmass of India heats up faster than the surrounding oceans, resulting in low-pressure areas over the land.
- As a result, cool and moist air from the oceans is drawn towards the land, creating the monsoon winds.
- These winds bring moisture-laden clouds, leading to rainfall.

Impact on Regions:

- The monsoon season affects different regions of India differently.
- The western coast of India, including states like Kerala, Karnataka, and Maharashtra, receive heavy rainfall during this period due to the direct impact of the southwest monsoon winds.
- The northeastern region of India, including states like Assam and Meghalaya, also experiences heavy rainfall during the monsoon season.
- In contrast, regions like Rajasthan and Gujarat in western India receive minimal rainfall as they lie in the rain shadow area, which is blocked by the Aravalli Range and the Western Ghats, respectively.

Other Seasons:

- While the monsoon season is the primary rainy period in most parts of India, there are other seasons when certain regions receive rainfall.
- The winter months of December to February see rainfall in parts of southern India, especially Tamil Nadu and Kerala, due to the northeast monsoon winds.
- The months of October and November witness post-monsoon rainfall in some regions, particularly in the southern states and parts of the northeastern region.

In conclusion, most parts of India receive rainfall during the months of June to September, known as the monsoon season. This period is crucial for the country's agriculture and overall water supply. However, it is important to note that there are other seasons when certain regions receive rainfall, such as the winter months and post-monsoon period.