Victorian firefighters will call on 114 interstate personnel from SA, the ACT, NSW, Queensland and the NT to help contain fires during cooler weather following a severe heatwave, State Control Centre spokesman Luke Heagerty said.
"We're really grateful for that support that's coming from interstate," he said on Wednesday.
Thunderstorms, lightning and erratic winds fanned the fire northwest of Little Desert. (HANDOUT/Horsham Incident Control Centre)
"We know that we'll make some great progress over the next few days, whilst the weather's on our side."
Three fires in the Grampians National Park joined late on Tuesday, with the southern fire ripping through burnt land to the north.
The risk has reduced for people at the top end of the Victoria Valley and around the town of Cavendish, but remains over the coming days for communities near Wartook, Mr Heagerty said.
Firefighters will prioritise protecting an unburnt 'gap' of land west of Halls Gap, which is close to several towns.
About 700 firefighters are battling uncontrolled flames there and further north at the Little Desert National Park near the SA border.
A cool change ushered in thunderstorms, lightning strikes and erratic winds fanned significant fire activity in the northwest of Little Desert.
"Crews, at this stage, are having some good success with slowing the spread of that fire once it reaches private land outside the park boundary," Mr Heagerty said.
Firefighters will spend much of Wednesday searching for new blazes sparked by overnight lightning strikes and further containment work, with no rain forecast in coming days.
Grazier Brett Monaghan last week quickly moved more than 400 sheep from his property at Brimpaen over concerns it was in the path of the northern Grampians fire and was prepared to do it all over again.
"I don't think anybody's completely relaxed at this point," he said.
His land is at the bottom of the Grampians mountains and he said nearby plumes of smoke were never far from his thoughts.
"Everybody's still keeping an eye out and I think everybody's still looking at the mountains every couple hours to just to make sure that the smoke's a long way away," he said.
"Depending on the wind, anything could happen".
As fires continue to burn, the National Rural Health Alliance and the Climate and Health Alliance have called for long-term solutions to build resilience in rural and regional health services to deal with more frequent extreme weather events which are causing significant and long-term health impacts.
"Health professionals are not currently equipped to deal with the frequency and scale of climate change events," National Rural Health Alliance chief executive Susi Tegen said.
"In recent weeks we have observed hospital admissions rise and health services unable to evacuate from fire zones, adding to mounting pressure."
35°C