In the summer season, around mid-July, the ITCZ shifts northward and roughly parallels the Himalayas between 20°N and 25°N.
The Inter-Tropical Convergence Zone (ITCZ) is a low-pressure zone located at the equator where trade winds converge.
It is a zone where air tends to ascend.
The Inter-Tropical Convergence Zone located around 20°N-25°N latitudes (over the Gangetic plain) in July month is sometimes called the monsoon trough.
This monsoon trough leads to the formation of thermal low over north and northwest regions in India.