The calm center part of a hurricane is called the eye.
The eye is a roughly circular region at the center of a mature tropical cyclone. Air in the eye generally sinks, producing lighter winds and often clearer skies than those found in the surrounding eyewall. It can range from only a few miles across to more than 60 miles in especially large storms.
The eye is surrounded by the eyewall, a ring of towering thunderstorms where a hurricane's strongest sustained winds and heaviest rain usually occur. This creates a dangerous contrast: conditions may suddenly become calm as the eye passes overhead, then rapidly deteriorate when the opposite side of the eyewall arrives.
The eye is not always perfectly calm or cloud-free, and weaker or developing storms may lack a distinct eye. Its formation is associated with the organized circulation and intense convection of a powerful tropical cyclone. The same feature is also found in typhoons and cyclones; the regional name differs, but the structure is essentially the same.