The nineteenth named storm of the below-average 2011 Pacific typhoon season, Haitang developed from a disturbance in the South China Sea.

At 15:00 UTC on September 21, the Joint Typhoon Warning Center (JTWC) began to monitor a low-pressure area persisting around 260 nautical miles south of Hong Kong.

On September 24, the Japan Meteorological Agency (JMA) would recognize the disturbance as a tropical depression east of Vietnam.

[5] Later that day, the storm became better organized; however, its low-level circulation center (LLCC) would become fully exposed due to moderate vertical wind shear from nearby Typhoon Nesat, which prevented further strengthening.

[8] Despite some bursts of convection, both land interaction and vertical wind shear would cause the system to weaken into a tropical depression, resulting in the JTWC issuing its last advisory on Haitang at 21:00 UTC that day.