Up to 70 flights have been cancelled in and out of Sydney airport as strong winds buffet the runways.
A Sydney airport spokeswoman said planes were restricted to using only one runway due to the gusty conditions on Thursday.
The Bureau of Meteorology has recorded wind gusts at the airport of up to 67km/h.
Strong winds are forecast to persist through the afternoon, with the Bureau of Meteorology issuing a strong wind warning for Sydney, and much of the NSW coast.
Passengers are being urged to check their flight details with their airlines.
It comes a day after Sydney experienced its hottest September day in 159 years, with windy conditions increasing the fire risk across the state.
The heat was fairly uniform across the basin on Wednesday, with most suburbs reaching at least 33 degrees. Sydney Airport hit 35.3 degrees and Bankstown 35 degrees.
The previous warmest temperature this early in the month for Sydney was 32.2 degrees on September 13, 2009, a level beaten by 1.6 degrees.
More than 90 fires are burning across NSW with about 30 of them out of control.
Firefighters will on Thursday focus on containing the fires, which took off during an unseasonably hot Wednesday, threatening homes in the NSW Hunter region and mid-north coast.
While conditions eased overnight the wind is forecast to pick up later on Thursday.
"Once the winds pick up with it will flare the fires again. By no means out of the woods. A lot of work to be done on the fire grounds today," Inspector Ben Shepherd told ABC on Thursday.
He said the ground is "extraordinarily dry".
Backburning is underway on the state's south coast at Summercloud Bay, near Jervis Bay.
The 11ha fire is under control and no homes are at threat, however Booderee campground has been closed.
The story, Dozens of flights cancelled, delayed at Sydney Airport due to gusty winds, first appeared on the Sydney Morning Herald.