Guangzhou's existing Terminal 1 was only designed to handle 35 million passengers a year, but a second, bigger, terminal will open next year. Expected to handle around 45 million passengers a year by 2020, the new terminal is being built at a cost of about 19 billion yuan.
Shenzhen is also planning a new terminal, with passenger traffic at the four-year-old airport now just 3 million short of its 45 million capacity.
However, Zhuhai, billed as China's biggest airport when it opened in 1995, has never come close to its 35 million passenger annual capacity.
People like retiree Zhu Yinghua and businessman Huang Honghui are making the most of the leisure and business opportunities provided by the region's increasing air traffic.
Zhu, a 65-year-old retired teacher from Guangzhou, made three overseas trips last year, visiting Russia, Turkey and the United States with her husband and friends. The trips cost between 6,000 and 10,000 yuan, quite affordable for retired teachers and civil servants in cities such as Guangzhou who receive monthly pensions of more than 6,000 yuan.
"It's much easier to travel to the other end of the world these days than travelling to Shanghai 20 years ago," said Zhu, who had never flown until 1993, when she was 41, and who made her first overseas trip in 1996 when she visited Singapore, Thailand and Malaysia via Hong Kong.
"I have to say now I like the Shenzhen and Guangzhou airports very much. They are more beautiful and modern than any other airport in China, including Beijing or Hong Kong."
The number of tourists heading overseas from mainland China has more than tripled in the past decade, hitting 122 million last year, and Guangzhou and Shenzhen are among the top sources.
The "Greater Bay Area", a region which includes Hong Kong, Macau, Guangzhou, Shenzhen, Zhuhai and some other mainland cities, is becoming the world's biggest market for aviation services. Passenger numbers in the region will reach 223 million a year by 2020, up from around 175 million last year, according to the China Civil Airports Association, which said such traffic would dwarf other bay areas such as Los Angeles, New York and Tokyo. Airports in the Tokyo Bay Area, home to 43 million people in 2015, handled more than 112 million passengers that year.