More from Daniella Miletic: A Qantas spokesman says they too are experiencing delays and cancellations - interestingly, on their outbound flights.
The spokesman said they were also tracking inbound flights but had not experienced any trouble "at this stage" with flights coming into Melbourne.
More confirmations of delays at Melbourne Airport. Daniella Miletic reports:
Flights are departing Melbourne but there are delays on arrivals. Jetstar has cancelled two return flights to the Gold Coast and there are delays up to two hours to allow conditions to improve.
A Melbourne Airport spokeswoman confirmed some delays on some domestic flights inbound, but said the delays were not significant.
It's a moody morning out there.
Making news this morning:
Here's what it looks like in print today:
VicRoads' Chris Miller has told radio station 3AW that the fog prompted him to slow right down on the drive to work.
"It's like pea soup out there," he said.
Most areas of Melbourne are affected. It's particularly heavy throughout the eastern suburbs and out to the airport, and out to Avalon in the west.
Motorists are urged to drive for the conditions. That means slowing down and using low-beam or fog lights.
There are a few flights delayed at Melbourne Airport. The website's flight tracker shows the arrival of three flights from Perth and Darwin are delayed.
Tiger flight TT426 was scheduled to land at 6.15am. It's now estimated at 7.08am. A Jetstar and Qantas flight from Darwin was scheduled for 6.40am, now estimated at 7.09am.
Flight tracker shows only two cancellations so far, for flights scheduled to take off to the Gold Coast at 6am. It's not known if this was fog-related. All other flights have departed.
Fog is down to 50 metres at Melbourne Airport, which is fairly similar to what we've seen for the last four consecutive mornings.
Bureau of Meteorology senior forecaster Stephen King says it's definitely one of the thicker ones we've seen in recent history.
Northerly winds should clear the air by midday.
Hello and welcome to Monday. It's foggy - and we're not just talking about our brains. In good news, the fog is trapping some warmth. It's just over 13 degrees in the city ahead of a sunny top of 28.
The fog on Friday didn't lift until midday. Will it be the same today? We'll find out as soon as this coffee kicks in.
Got a picture or a report on the fog? Send it our way via email or Twitter.
Bad news already for train commuters on the Cranbourne and Pakenham lines, where an equipment fault at Westall is already causing major delays.