Why does a low-pressure system form over the continent during the summer monsoon?

A low-pressure system forms over the continent during the summer monsoon primarily due to the differential heating of land and sea. Because seasonal temperature changes are much larger over land than over ocean waters, the continent acts as a significant heat source, while the cooler ocean serves as a heat sink.1

As the Northern Hemisphere summer progresses, the land—particularly regions like the Plateau of Tibet and the Indus River basin—absorbs and radiates intense heat. This heating warms the air above the surface, causing it to become unstable and rise. The resulting low-pressure area, often referred to as the South Asian low, draws in moist, unstable air from the high-pressure regions over the ocean.2134

Additionally, the release of latent heat during the condensation of water vapor in towering cumulonimbus clouds further contributes to the warming of the upper troposphere, reinforcing the low-pressure conditions at the surface.43