A sea breeze or seabreeze is a thermally-forced mesoscale (i.e. local-scale) meteorological circulation that develops across boundaries of water and land surface types, especially coastal regions. Due to solar heating and the thermal properties of land and water, the land surface heats up faster than the ocean surface. Thus, the airmass over land becomes warmer, less dense and rises, lowering the barometric pressure over the land. The cooler surface air over the ocean then flows towards this lower pressure, lowering the temperature of the land area. Sea breezes occur most often in the summer season when there is a large temperature differential between the air temperature over land and the air temperature over the ocean. The air temperature over the ocean is mostly correlated with the temperature of the ocean water which is slower to respond to heating of the Sun because of the thermal mass of the ocean water.

A seabreeze front is a type of mesoscale (i.e. local scale) weather front created by a seabreeze, and in humid and unstable air often triggers strong thunderstorms. This frequently happens in Florida, a peninsula surrounded on both the east and west by the Atlantic Ocean and Gulf of Mexico, respectively. No matter which direction the winds are blowing, they are always off the water, thus making Florida the place most often struck by lightning in the United States, and one of the most on Earth. On especially calm days with little prevailing wind, seabreezes from both coasts may collide in the middle, creating especially severe storms down the center of the state. These storms also tend to produce significant hail due to the tremendous uplift it causes in the atmosphere.

At night, a sea breeze may reverse itself into a land breeze, sometimes causing showers or thundershowers over the water. In Florida, a seabreeze pushed by prevailing winds may also continue past the land and out over the water at night, creating spectacular cloud-to-cloud lightning shows for hours after dark.