A thick blanket of fog settled in over Sydney this morning, causing transport chaos.

All ferry services were cancelled this morning due to low visibility, but have now returned to action as the sun burns through.

Thousands of harbour commuters were forced onto buses, causing significant delays.

Ferry services on #Sydney Harbour are resuming as thick blanket of fog begins to burn off. Harbour Bridge still smothered but blues skies now visible @2GB873 #MRNnews pic.twitter.com/8uPfMHSKyE

— Emily O’Brien (@EmilyC_OBrien) July 4, 2018

Low visibility procedures are now being lifted at Sydney Airport after several flights were delayed and cancelled this morning.

Low visibility procedures in place @SydneyAirport this morning due to fog, but we are still seeing arrivals and departures and no diversions reported. For cancellations please check with your airline. Happy and safe travels!

— AirservicesAustralia (@AirservicesNews) July 4, 2018

The fog has been caused by warmer temperatures in Sydney, which will experience two unseasonably warmer days.

When the fog eventually lifts, the Harbour city in for a beautiful sunny day with an expected top of 23 degrees. Seven degrees above average.

Image: Matt de Groot

Early morning in Sydney #Sydney #fog #sydneyfog pic.twitter.com/oSIKnbld9i

— Cat (@CatCranston) July 4, 2018