China's State Oceanic Administration (SOA) issued the red alert for ocean waves and storm tides as Typhoon Nida, packing winds of 130 kilometers per hour, approaches the mainland.
The airlines will waive fees on re-booking, re-routing and cancellation and refund for all tickets issued worldwide on or before August 1 for travel on Cathay Pacific and Dragonair involving Hong Kong between August 1 and Aug 3, said the statement.
Over 120 flights to and from Hong Kong have been canceled as Typhoon Nida barrels toward the city and southern China, after battering the Philippines over the weekend.
China has a four-tier, colour-coded weather warning system, with red representing the most severe weather, followed by orange, yellow and blue.
The China National Commission for Disaster Reduction has asked people in typhoon-affected areas to stock daily necessities for at least one to three days, the circular said, adding that emergency mechanisms for disaster relief will be activated if necessary. Members of the public have been advised to stay indoors, Xinhua reported.
At about 7am on Monday, Nida was about 580km away from Hong Kong.
More than 220 flights out of Guangzhou, Shenzhen and Zhuhai airports would be cancelled before the storm passes over today, the Sohu news portal said.
The Hong Kong Observatory has announced that the Tropical Cyclone Warning Signal Number 8 is expected to be issued at or before 8:40pm on Monday.
"Local winds are expected to strengthen significantly around dusk", a weather bulletin said. "There may be flooding in low-lying areas".
Earlier this month, Typhoon Nepartak drove at least 420,000 Chinese from their homes and caused more than 7.1 billion yuan (S$1.43 billion) in losses in Fujian province alone, Reuters said.