Firefighters are preparing for weekend weather expected to rival the devastating conditions that saw fire wreak havoc on the South Coast on New Year's Eve.
NSW Rural Fire Service deputy commissioner Rob Rogers said conditions on Saturday had the potential to be as bad, or worse, than those experienced on Tuesday.
"The winds are expected to be very strong, back to 40-plus degrees temperatures. We've got a lot of fire in the landscape that we will not contain," he said.
"Over the next 24 hours we'll be doing some specific communications to those people potentially in the path of fires down south, but also those ones around Sydney where we think there's a likelihood of those fires threatening communities.
"And I think the message is going to be simple, like we've said previously, do not be in the path of these fires."
Deputy commissioner Rogers warned the fires were burning extremely ferociously.
"We've unfortunately seen how deadly they are," he said.
"We'll be working very much with transport and police about how to get people who are in potentially threatened areas out, given the dislocation to the road system down south. We'll be trying to work at that ahead of deteriorating conditions for Saturday."
NSW Rural Fire Service commissioner Shane Fitzsimmons said, "The challenge through the South Coast is you have two winds that will be competing against each other on Saturday, a westerly and an easterly.
"When they converge together [they] create all sorts of ... wind directions and all sorts of convergence over a fire ground which is going to increase the risk and the damage."
The Bureau of Meteorology is forecasting rising temperatures as the week progresses, with stronger winds on Saturday.
Forecaster Rose Barr said Canberra could expect a build up of heat over the next few days, reaching about 40 degrees on Saturday.
"Canberra will be seeing something of a repeat of lighter winds during the day, then an easterly in the evening," she said.
"They are likely to push through this smoky condition."
But the thickness of the smoke will depend on the intensity of the fires.
A top of 35 degrees is forecast in Canberra on Thursday, 39 on Friday and 41 on Saturday.
For the South Coast, the forecast is for slightly cooler temperatures on Thursday and Friday but rising to the high 30s and low 40s on Saturday.
In Batemans Bay a top of 25 degrees is forecast on Thursday, 29 on Friday and 40 on Saturday. In Bega, a top of 28 degrees is expected on Thursday, 31 on Friday and 43 on Saturday.