Flying catkins, the cotton-like seed clusters that cause discomfort and fire hazards during spring, have been spotted in the central and southern parts of Beijing, as the city government announced the beginning of this year's catkin season on Sunday.

The Beijing Municipal Forestry and Parks Bureau and the city's meteorological service forecast that the northern districts will see catkins from Monday.

Three high-incidence periods of poplar and willow catkins have been predicted in mid-April, late April to early May, and mid-May, affecting downtown areas as well as mountainous regions of the capital.

The public has been urged to wear dust masks, sunglasses, goggles or scarves to block flying catkins.