A police roadblock at the junction between Grampians Road and Ararat-Halls Gap road will be opened between 10am and noon on Christmas Eve
Proof of residence will be needed to access the areas, which have been engulfed by a 41,000-hectare inferno for the past week.
Residents will be allowed to return home during a brief reprieve in fire conditions. (James Ross/AAP PHOTOS)
Country Fire Authority chief officer Jason Heffernan said the temporary access was to help allow some festive normality for locals.
"In what I'm calling Operation Yuletide, we are allowing the residents under emergency services escort back into their properties ... to get Christmas items ... presents and the like," he told Seven's Sunrise program on Tuesday.
"(This is) to ensure if the residents of Halls Gap will be relocated for Christmas, at least they will have what they need."
Mr Heffernan said cooler, milder conditions on Monday night helped firefighters on the ground in getting "some containment" of the southern Grampians fire.
Another bushfire at Bullengarook in Melbourne's northwest has been contained, while a blaze at the Gurdies in western Gippsland continues to burn.
Holiday travellers are being warned to keep up to date with fire conditions as several states face growing bushfire risks.
Conditions are set to intensify across the state when temperatures reach into 40C on Boxing Day, fanned by strong and dry winds, Victorian Emergency Management Commissioner Rick Nugent said.
"We have some very difficult weather conditions on Thursday and Friday," he said.
"These conditions will make it far easier for fires to start and to spread and for existing fires to race off in the direction of the wind."
Elsewhere in NSW, several small bush and grass fires continue to burn but remain under control, though a significant part of the state also faces high fire dangers on Boxing Day.
Firefighters in several states are preparing for challenging conditions on Boxing Day. (James Ross/AAP PHOTOS)
South Australian firefighters urged residents to leave in the Onkaparinga Hills in the Mount Lofty Ranges as they battled an out-of-control bushfire on Monday.
They later downgraded warnings, telling residents to monitor conditions.
Regional areas across SA are expecting hot conditions on Boxing Day, with Adelaide facing a peak of 36C after a predicted 37C on Christmas Day.
Firefighters in Western Australia on Monday night upgraded a bushfire alert, warning residents it was "too late to leave" as a blaze intensified about 100km northeast of Perth, near the wheatbelt town of Northam.
The fires already burning across Victoria have the potential to worsen as extreme hot weather blankets most of the state on December 26, leading to authorities pleading with travellers to reconsider their trips.
"Our state will have all areas ... in extreme fire danger rating, except for East Gippsland on Thursday," Mr Nugent said.
About 100 fire personnel from NSW, the ACT, Queensland and Tasmania are heading to Victoria to help battle the blazes.
29°C