Justice Wilson Chan granted the extension at the High Court a little more than a week after a five-day mass sit-in, which started as a peaceful occupation but later descended into chaos, with protesters blocking passengers from leaving, scuffling with them, and even holding two mainlanders hostage, the South China Morning Post reported.
The order was renewed ahead of another protest planned at the airport on Saturday.
Extending the order, Chan noted that while the disturbance had subsided the threats to the airport remained, including repeated calls on social media urging others to obstruct and interfere with passengers.
"The smooth running of the airport is of crucial significance to Hong Kong, in particular the security and safety of its citizens and travellers, its commercial interests, as well as its international reputation," he said.
The Hong Kong Airport Authority went to court on August 13 in a closed-door proceeding to seek the order after hundreds of flights were cancelled.
Friday's hearing was open to the public, in contrast to the first hearing, which was so secretive security officers even denied it was happening, and forced reporters to leave the court building.
Protesters began to occupy the airport on August 9 to take their cause to travellers. But the protests descended into chaos on August 13, when some demonstrators attacked two people from China, including a journalist for the state-run Global Times newspaper, reports the South China Morning Post.
A total of 979 flights were cancelled last week.
( With inputs from IANS )