The Illawarra is expected to escape the brunt of the severe heatwave forecast for much of the state this week, but some parts of the region will top 39 degrees by Saturday.
The Bureau of Meteorology has forecast severe heatwave conditions for NSW, with places such as Cobar, Broken Hill and Griffith to see temperatures above 40 degrees in the coming week.
A low intensity heatwave is forecast across the Illawarra and South Coast, with temperatures in Wollongong expected to hit 27 degrees on Wednesday and 33 degrees on Thursday. Friday is expected to be milder before rising to 32 degrees on Saturday.
At Albion Park, the temperature will hit 32 degrees on Wednesday, 37 degrees on Thursday and 39 degrees on Saturday with winds up to 40km/h, the bureau said.
In Bowral, the bureau forecasts 35 degrees on Wednesday, 37 degrees on Thursday and 41 degrees on Saturday.
Health authorities have warned smoke haze may settle across the region with fires continuing to burn on the South Coast at Currowan and the Gospers Mountain fire north-west of Sydney.
The Rural Fire Service has issued a high fire danger rating for the Illawarra and Shoalhaven areas on Monday.
With 110 fires burning in NSW the RFS is quite concerned about conditions from Wednesday onwards.
"There's going to be a lot of work going on over the next 24 hours to try and just see what we can do to protect as many properties as we can, but people should be under no illusions," RFS deputy commissioner Rob Rogers said on Sunday night.
"We're going to have to get through this next week of really hot weather with these fires being very active."
Some 724 homes, 49 facilities and 1582 outbuildings had been destroyed so far this fire season. Six people have died and 2.7 million hectares have been scorched.
- with AAP