Global winds are caused by differences in air pressure from the uneven heating of the Earth. This uneven heating produces pressure belts that drive the three main types of global winds: polar easterlies, westerlies, and trade winds. Local winds such as sea breezes and land breezes are also caused by temperature differences, with sea breezes blowing from ocean to land during the day when land is warmer, and land breezes blowing from land to ocean at night when the water is warmer.