The Saffir-Simpson scale rates tropical storms and hurricanes on a scale from 1 to 5 based on their maximum sustained winds. The top of the scale is currently marked as Category 5 for storms with sustained winds greater than 156 mph.

In 2023, amid increasing concerns over the power and impacts of tropical cyclones fueled by a warming climate, the United Nations World Meteorological Organization received a proposal from the United States to add a Category 6. In February 2023, the agency deferred its decision to introduce a new category for another two years, citing the need for further studies.

Some experts have argued that creating a Category 6 could serve as a wake-up call to communities living in hurricane-prone areas, prompting better preparations and disaster mitigation measures. However, others have raised objections, including the potential for public misinterpretation and the complexity of determining thresholds for an additional category.

The National Oceanic and Atmospheric Administration (NOAA) scientists stated that adding a sixth category would not provide a significant benefit for disaster preparedness and response but could inadvertently lead to miscommunication and confusion about hurricane risks and impacts.