Fog blanketing Sydney on Saturday caused delays or diversions to a number of flights, while contributing to hazardous conditions on the roads.
A handful of Qantas, Virgin Australia and Tigerair flights in and out of Sydney have been delayed, cancelled or rerouted due to Saturday's weather.
International passengers at the T1 terminal are experiencing delays of up to 30 minutes, mostly in arrivals, a Sydney Airport spokesman told AAP on Saturday morning.
Domestic passengers at the airport's T2 terminal are being delayed between 90 minutes to two hours for both arrivals and departures, the spokesman said.
A Qantas spokeswoman said passengers on cancelled flights to Canberra and Melbourne have been transferred to other services.
Travellers are advised to check their flight's status with their airline.
Saturday flights on regional carrier Rex are also delayed to and from towns including Cooma, Armidale, Narrandera, Griffith, Albury, Orange, Merimbula, Newcastle, Parkes, Wagga Wagga and Broken Hill.
The Bureau of Meteorology has issued a road weather alert for the city.
"Reduced visibility in fog will make road conditions dangerous during Saturday in all suburbs. Motorists are advised to take extreme care," it said.
