34. Perfect Storm of Freaky Weather
History’s worst natural disaster was caused by a perfect storm of extreme weather phenomenon, all coming together at the worst possible time. It began with a severe drought that hit China from 1928 to 1930. That was followed by an exceptionally severe winter in 1930, which deposited unusually massive amounts of snow and ice in the mountainous areas upstream from the Yangtze and Huai rivers.
In the early spring of 1931, all that snow and ice melted, and flowed downstream into the two rivers. It reached the middle Yangtze just as the region was experiencing exceptionally heavy spring rains. Things were made worse still by an unusually high number of cyclones. On average, the region experiences two cyclones a year. In 1931, it was hit by nine cyclones. All of those factors combined to bring about a calamity.