The monsoon regime emphasises the broad unity of India with the rest of southeast Asian region. However, this unity should not lead one to ignore the regional variations which differentiate the weather and climate of different regions of India.

The climate of different regions shows significant variations. For example, the climate of Kerala and Tamil Nadu in the south is very different from that of Uttar Pradesh and Bihar in the north, yet all these regions have a monsoon type of climate. These regional diversities are described as sub-types of monsoon climate.

Distance from the sea creates regional variations in climate. Coastal areas like Mumbai and the Konkan coast have an equable climate with hardly any extremes of temperature. In contrast, interior areas like Delhi, Kanpur and Amritsar experience extremes of climate with sharp seasonal contrasts.

Altitude also causes regional variations. Places in the mountains are cooler than places on the plains due to thin air. For instance, Agra and Darjiling are located on the same latitude, but January temperature in Agra is 16°C whereas it is only 4°C in Darjiling.

The relief or physiography affects temperature, air pressure, direction and speed of wind, and the amount and distribution of rainfall. These regional climatic variations are reflected in the vast variety of food, clothes and house types across India.