Cyanobacterial blooms are one of the most significant global challenges affecting aquatic ecosystems. Both their outbreaks and dissipation pose serious threats to the ecological environment of the affected water bodies and the safety of surrounding drinking water sources. As one of China’s five largest freshwater lakes, Hulun Lake plays a crucial role in maintaining the stability of the local ecosystem. This study monitors and identifies cyanobacterial blooms in Hulun Lake by converting the surface reflectance of blooms in Landsat imagery into the CIE-xy chromaticity space. A dataset covering cyanobacterial bloom outbreaks in Hulun Lake from June to September for each year from 2003 to 2023 was generated. The study finds that wind speed and temperature are among the key factors driving the cyanobacterial blooms, with their effects becoming apparent 1 to 5 days after these conditions occur.