The main cause of the flood was due to above average rainfall in the region for several months before and during the summer of 1998.

The floods can be split into three general stages, beginning when one of the strongest subtropical highs in history arrived in the Yangtze River Basin during mid-June and lingered, providing sustained heavy rainfall for a period of roughly two weeks.

[7] Another 300-500 mm of rain was seen across several areas during this second phase, causing significant damage as it flowed into villages and towns.

[7] Although the water had begun to subside at this point, this extra rainfall caused further damage to homes and farmland in the surrounding areas.

[8]: 26  After investigating, government scientists attributed much of the cause for flooding to upstream deforestation that had occurred during logging booms in the previous two decades.