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Chicago Weather Center

Ask Tom why: What is the difference between a hurricane and a typhoon?

October 1, 2011

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Dear Tom,

I recently heard about the typhoon hitting Japan and the hurricanes off the East Coast. What is the difference between the two?

—Julie, Lake Villa

Dear Julie,

Location is the only difference between a hurricane and a typhoon. When winds reach 74 mph, tropical cyclones are given the regionally specific name of hurricane in the Atlantic, Caribbean and the northeast and southwest portions of the Pacific, while in the northwest Pacific the storms are referred to as typhoons. To be classified as a typhoon, a storm must develop or move west of the 180th meridian (International Date Line) just like Typhoon Roke that recently just hit Japan. These storms also develop in the Indian Ocean where they are referred to as cyclones or severe cyclonic storms. In a typical year, as many as 90 tropical cyclones may develop globally.