Thick fog has wreaked havoc on the plans of thousands of travellers into and out of Sydney Airport, with dozens of flights cancelled, diverted or delayed.
The heavy shroud had lifted by 9am on Monday, but not before one international flight was diverted to Brisbane and about 10 incoming and departing domestic flights were cancelled.
Jetstar, Eastern Australia Airlines and Sunstate Airlines all cancelled several flights around 8am.
More than 40 flights on the domestic arrivals board were delayed, while a handful of Qantas, Tigerair and Virgin Australia domestic departures were also left in limbo.
Some incoming flights from Abu Dhabi, Denpasar, Toronto, Los Angeles and Seoul did not arrive on time, however, international departures were largely unaffected.
Sydney Airport remains operational, but travellers are advised to check flight details with their airline.
A Bureau of Meteorology (BoM) spokesman says residents in Sydney's west, near Richmond and Camden, should be able to see clearly by midday.
A Transport Management Centre spokesman told ABC Radio it was still "exceptionally foggy" around Sydney at 8.30am and traffic was building up around the airport as people return home from the long weekend.
"But when we've got a foggy morning, it's usually an indicator that we're going to have a great day," he said.
"The sun will shine, the sky will be blue; it'll be fabulous."
The weather bureau has forecast mostly sunny conditions for Monday, with Sydney temperatures hitting 20 degrees with light winds and a slight chance of a shower in the afternoon and evening.
