The winds of winter The polar vortex is an enormous, three-dimensional ring of winds that surrounds the North and South poles during each hemisphere’s winter. These winds are located about 10 to 30 miles (16 to 50 km) above Earth’s surface, in the layer of the atmosphere known as the stratosphere. They blow from west to east with sustained speeds easily exceeding 100 mph (160 kph). In the darkness of the winter polar night, temperatures within the polar vortex can easily get lower than minus 110 degrees F (minus 79 degrees C). Fortunately for everyone, the stratospheric polar vortex itself won’t appear outside your front door. The polar vortex does influence winter weather, but it is more like a domino: when it is knocked over, it can start a chain of events that later result in wild weather.