World’s wettest rainstorms are getting wetter, affecting flood and drought risk

Events that deliver about half of global rainfall are getting shorter but more intense, with wide-ranging implications

The world’s wettest rainstorms produce about half of the global annual rainfall. Now a study shows that these intense downpours have become shorter in duration and fewer in number, compressing the same amount of rain into quicker and more extreme events, with implications for flood and drought risk.

Chiyuan Miao and colleagues from Beijing Normal University in China analysed daily measurements between 1980 and 2022 from more than 19,000 rain gauges around the world. They found that an average of about half of the world’s rainfall fell during about nine multi-day storms, delivered over a cumulative time of about 28 days.