An anticyclone is a large weather system where air pressure is higher in the center than in the surrounding areas. Think of it as the opposite of a storm: while hurricanes and cyclones spin inward with rising air that creates clouds and rain, an anticyclone spins outward with sinking air that pushes clouds away and brings clear skies.

In the Northern Hemisphere, anticyclones spin clockwise (like the hands of a clock), while in the Southern Hemisphere they spin counterclockwise. This happens because of Earth's rotation, which affects how air moves across the planet's surface.

When an anticyclone settles over your region, you can usually expect calm, pleasant weather: blue skies, gentle breezes, and dry conditions. In summer, anticyclones can bring hot, sunny days that stretch on for weeks. In winter, they often create cold but beautifully clear weather.

Meteorologists track anticyclones on weather maps, marking them with an “H” for high pressure. These systems can be enormous, covering several states at once, and they tend to move slowly across continents. While they usually mean good weather, anticyclones can also trap pollution close to the ground in cities because the sinking air prevents it from dispersing upward.