Cold and damaging winds are buffeting Sydney and the New South Wales southern coastline, just one day after a second cold front wreaked havoc at Sydney Airport.

Key points: Windspeeds exceeding 90kph were recorded in south-east NSW around 2:00pm

Windspeeds exceeding 90kph were recorded in south-east NSW around 2:00pm Jetstar domestic flights are expected to be delayed for more than an hour on Sunday afternoon

Jetstar domestic flights are expected to be delayed for more than an hour on Sunday afternoon Over 200 calls for help were made to the SES in the past 24 hours

Hundreds of flights were cancelled or delayed at Kingsford Smith Airport on Saturday when damaging winds closed all but one runway, leaving thousands of passengers stranded and frustrated.

On Sunday, only one runway was operating from 3:00pm onwards due to the high winds, causing widespread delays across domestic and international flights.

All three runways reopened at 6:50pm, Sydney Airport confirmed.

The Bureau of Meteorology (BOM) said Sydney and south-east NSW was lashed by damaging winds and blizzard-like conditions.

"Yesterday we saw quite strong wind gusts. Today we also have another front moving through during the afternoon and through to the evening … and into early Monday," BOM meteorologist Rob Taggart said.

He said the bureau recorded windspeeds exceeding 87kph at the Blue Mountains and 96kph at Port Kembla and Albion Park near Wollongong on Saturday.

Similar conditions were predicted for Sunday afternoon before easing on Monday evening as the cold front moved east, away from NSW.

"We can expect to see gusts exceed 90kph, which is basically what we saw the other day," Mr Taggart said.

In an update at 5:30pm on Sunday, BOM said a series of cold fronts would continue to generate "strong and gusty winds" over NSW.

"The new front currently clipping the south-eastern corner of the state will continue to move north, bringing another bout of vigorous west to south-westerly winds for the rest of the today into Monday morning, then the winds are forecast to ease by late Monday morning as the front moves east away from New South Wales.

"Another front will move through the south-east on Wednesday, but it is unlikely to be as strong as those preceding it."

More delays at Sydney Airport

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 1 minute 12 seconds 1 m 12 s Travellers experience more delays at Sydney Airport.

Sydney Airport's domestic terminal became a crowded waiting area for families and travellers, some of whom will not be able to board a flight until Monday.

One family who landed in Sydney from Hong Kong were surprised to find their connecting Jetstar flight to the Gold Coast was cancelled and every other flight home was booked out.

The father told the ABC they would be out of pocket if they booked accommodation — Jetstar had advised passengers on Saturday night there would be no cash refunds for cancelled or rescheduled flights.

"There's no flight until tomorrow evening, we could probably drive to the Gold Coast quicker," he said.

A Jetstar spokesman told the ABC the airline was expecting hour-long delays on at least 10 domestic flights.

A Virgin Australia spokesman said it had no cancellations but had been hit by delays and was advising passengers to check the status of their flights online.

"We are experiencing delays to flights due to strong winds in Sydney this afternoon," the spokesman said.

"We're working to get our guests on their way as quickly and safely as possible."

SES on standby

The windy conditions were not just confined to Sydney.

The state's south-east — particularly the Illawarra, Southern Tablelands and the Snowy Mountains region — was expected to be pummelled by damaging winds averaging 60 to 70kph on Sunday afternoon.

At higher elevations, peak gusts were predicted to exceeded 120kph.

The SES responded to downed trees in Blacktown on Saturday. ( Facebook: SES Blacktown )

The NSW State Emergency Service (NSW SES) said extra personnel were on standby.

NSW SES spokesperson Jason Sims said they had responded to more than 200 calls for help in the 24 hours since heavy winds downed trees across NSW on Saturday.

"We've been out to numerous locations around the south-eastern parts of the state," he said.

"The worst we've seen is up around the Blue Mountains followed by the south coast, the Illawarra and parts of the metro."

Statewide, the NSW SES received 450 calls since the severe weather warnings were issued on Thursday — 91 of those were for the Blue Mountains alone.