What causes the wet season? (TMC)

In summer hot air rises due to convection creating a thermal low pressure over the land 

The meeting of two areas of low pressure (equatorial and thermal) causes them to merge to replace air that is rising 

The relatively cool sea is high pressure compared to the land so wind blows inland causing rainfall

Relief rainfall as air forced over the Western and Easter Ghats 

In January the ITCZ and subtropical jet stream move southwards over the equator and towards the tropic of capricorn 

High pressure system forms in Kashmir due to cold land causing air contraction 

This produces outward blowing winds flowing towards the equatorial low pressure, centred in the Southern hemisphere