The Inter Tropical Convergence Zone (ITCZ) is a very prominent summer feature in both the Northern as well as the Southern Hemisphere. Practically, it runs around the earth in the tropics. The Northern Hemisphere ITCZ during the summer months is the Monsoon trough.
Broadly, the Monsoon regime lies between latitude 5°N of the northernmost surface position of the ITCZ in July and the Latitude 5°S of the southernmost position of the ITCZ during the month of January. The ITCZ is more prominent in the Afro-Asia Australian region.
The onset of Monsoon is predominantly manifested by the cross-equatorial flow of winds. These winds crossover from south to north of Equator and change direction from southeast to southwest which is why the name Southwest Monsoon. The stronger the flow of the winds, more aggressive is the wind surge during the onset phase.