The terrific Tongking typhoon (Dechevrens, 1882) of early October 1881 spread destruction and calamity along the coast of what is now northern Vietnam. The young port town of Haiphong, located roughly 16 kilometres inland from the Gulf of Tonkin on a branch of the Red River, was entirely swept away, whilst terrible floods devastated the surrounding low-lying delta.

The early development of the tropical storm took place in late September 1881 somewhere east of the Philippines, in the Philippine Sea or out in the open North Pacific Ocean. By the time the storm traversed the island of Luzon on 30 September its increasing strength was already sufficient to cause loss of life and disrupt shipping. The system intensified significantly in the South China Sea before entering the Gulf of Tonkin on a curving trajectory (Figure 1). Travelling at an approximate average speed of 14.5kmh−1 from Luzon, the typhoon eventually made landfall on the Tonkin coastline on 5 October. On his original map of the typhoon's movement, Marc Dechevrens, then Director of Zi-Ka-Wei Meteorological Observatory near Shanghai, showed a pair of tracks that gradually diverged after 2 October in the South China Sea, because he suspected that high land on Luzon had split the typhoon into two distinct ‘whirlwinds’. In the 1880s, splitting was a phenomenon believed to have affected other typhoons that had passed over the mountains of Formosa (Taiwan). Nowadays we know otherwise: migrating tropical storms have been known to merge, but it is physically improbable for a typhoon to split into two separate typhoons. For this reason, we believe that after 3 October the actual track probably lay somewhere in between the two tracks originally suggested by Dechevrens. Supporting evidence is that anticlockwise wind circulation around the eye would have driven large waves against the Tonkin coastline and pushed the storm surge up branches of the Red River towards Haiphong, so leading to the widespread flooding that was experienced in the low-lying delta (described below). In contrast, an alternative migratory path farther east (similar to the eastmost track of Dechevrens) would have instead directed wind and waves offshore during the typhoon's approach up the Tonkin Gulf towards the Tonkin coast (modern northern Vietnam).