As of Thursday evening, NSW had some 115 fires ablaze, with about 50 yet to be contained, Ben Shepherd, a senior spokesman for the Rural Fire Service, said.
The Bureau of Meteorology also issued on Thursday a severe thunderstorm warning for damaging winds, heavy rainfall and large hailstones for a large inland region stretching from Inverell and Armidale in the north, down to the Victorian border.
A second warning covered a separate swathe from Bourke down to Deniliquin.
For Sydney, conditions are likely to be dry with temperatures remaining in a narrow range well into next week. Most days will reach about 29 degrees, after overnight lows only dipping to the low 20s.
Inland suburbs will be at least six degrees warmer than the city during the day, with minimum temperatures also remaining above 20 degrees until Wednesday when a cool change arrives with some rain.
In the Blue Mountains, the main area of concern is the Newnes Plateau and state forest near Lithgow, where nine fires have been burning since last week. Five or six fires are under control, Inspector Shepherd said.
While strong winds aren't expected over the weekend, any lightning could trigger new blazes with conditions in many areas remaining "extremely dry", he said.
#AustraliaDay holidaymakers urged to reconsider plans to visit/stay in the Newnes Plateau region & Newnes State Forest near Lithgow this long weekend due to significant fire activity. Further info at Forestry Corp website: https://t.co/1M9A6ScvHv#NSWRFSpic.twitter.com/eeizBvdwlE??? NSW RFS (@NSWRFS) January 25, 2018
Last weekend's fires in the Royal National Park aren't likely to pose risks to visitors, although some tracks will be closed including the popular coastal track south to Garie, Inspector Shepherd said.
Any campers lighting fires in the open where they are permitted should ensure they are "100 per cent out" when they leave, he said.
For Friday, Australia Day, the fire danger ratings are high in regions such as Sydney and the Hunter but low to moderate for most of the state.
"We don't expect the fire danger to reach "severe" over the weekend," Inspector Shepherd said.
Still, travellers should not pass road blocks set up where fire-fighting activity may be under way. They should also be aware poor or absent mobile phone coverage will inhibit their ability to receive text alerts, he said.
Much of southern Australia is in for a hot weekend, particularly Victoria and Tasmania, where high humidity levels could make for some uncomfortable conditions.
According to the bureau's heatwave service, most of Victoria can expect "severe" heatwave conditions for the Friday to Sunday period, with parts of Tasmania reaching "extreme". (See chart below.)
The story Dozens of fires burning across the state to affect long weekend holidaymakers first appeared on The Sydney Morning Herald.