On a sunny day the land heats more quickly than the adjacent ocean. The warmer air over land rises, and cooler air from the sea flows inland to replace it. That onshore flow is the sea breeze.

The breeze typically begins in the late morning, strengthens in the afternoon, and dies out after sunset. It can penetrate tens of kilometers inland and often brings a noticeable drop in temperature and rise in humidity. A boundary called the sea-breeze front may trigger clouds or showers as it moves ashore.

Coastal communities rely on the cooling effect of the sea breeze during hot weather. The circulation is reversed at night when the land cools faster, producing a land breeze. Local topography and larger-scale winds modify the strength and timing of the sea breeze.

Satellite imagery sometimes reveals the clear area offshore and the cloud line inland associated with the circulation.