HONG KONG — Air pollution in Hong Kong, one of the perpetual banes of living and working in this Asian financial hub, reached record levels on Monday and remained intense on Tuesday, setting off an official government warning to avoid outdoor activities and physical exertion.

Pollution levels have been elevated in the city for days, casting a gray pall over the harbor and obscuring views of Hong Kong’s famed skyline. But by Monday, Hong Kong’s official air pollution index rose further still, to the worst levels since records started being kept in 1995, said a spokeswoman for the Environmental Protection Department.

Air pollution index levels at several measurement stations soared above the top end of the government’s 500-point air pollution index by Monday evening.

Pollution levels were 12 to 14 times the amount recommended by the World Health Organization, estimated the Clean Air Network, which campaigns to inform the public on Hong Kong’s pollution issues, on Monday.