Air services across much of South Australia's arid interior are returning to the skies after being forced to spend most of Monday morning grounded due to fog.
The town of William Creek, west of Lake Eyre, remained blanketed by thick fog as late as 10am.
Local publican and pilot Trevor Wright said it was as intense a fog as he had seen in decades.
"We've heard flights into Olympic Dam had to turn around and come back," Mr Wright said.
"We've had visibility here at only 100 metres and cars are going about 20 kilometres an hour, so everyone's taking it very carefully.
"The big issue is the area it's covering and the thickness of the fog."
The road from William Creek to Marree, south of Lake Eyre, has been closed due to wet weather.
Marree Hotel operator and pilot Phil van Wegen said it was impacting tourist travel through the area.
"We've had a good crowd of people as the outback tourism season kicks off, but the fog and road closures have certainly caused a bit of a backlog," Mr van Wegan said.
"It was really pretty heavy this morning, we had to delay a number of flights."
'Very large area' of fog to clear
Bureau of Meteorology duty forecaster Hannah Marsh said moisture from a low pressure trough moving east had caused the fog.
"When we see in excess of close to 40mm, like we saw at Blinman, there's a lot of moisture hanging around, so you can expect that fog to be very thick," Ms Marsh said.
"It was a very large area extending from the northern Eyre Peninsula to the Flinders Ranges and up to Coober Pedy and Moomba.
"There's a possibility of seeing fog tomorrow morning but we're not expecting it to be as wide spread as today."
