Despite an "Antarctic cold snap" hitting Victoria this week, fires are likely to continue burning in an open-cut mine at the state's biggest power station in Latrobe Valley.

State Control Centre meteorologist Kevin Parkyn said blazes like the Hazelwood mine fire could burn even in winter.

On Saturday, more than 170 CFA and MFB firefighters continued to battle the fire around the clock, while carbon monoxide levels were declared safe.

Mr Parkyn said humid weather conditions from next week meant there was unlikely to be any elevated fire danger for some time.

"Things, while they're quite warm, they're fairly humid, and when we get these humid conditions, it suppresses the risk of fire spreading in the landscape.

"By mid-week, we've got an Antarctic cold snap and we'll see maximum temperatures to just in the teens on Wednesday and probably Thursday as well across southern Victoria.

"The bureau is actually forecasting possibly snow flurries on some of the higher peaks in the alpine district, so we're going from a heatwave to a cold outbreak."

CFA state duty officer Brett Boatman said on Sunday that firefighters were battling three major fires in far-east Gippsland, along with the Hazelwood mine fire.

There was no threat to the state's power supply because the fires were in an area of the mine not being dredged for coal, he said.

"The weather outlook for the week ahead is favourable for all fire agencies," Mr Boatman said.

"We've had significant rainfall across the north west of the state.

"After Tuesday, we've got what the bureau is calling a cold outbreak which brings us way back down in temperatures and south-westerly winds and that also reduces our fire danger ratings over the next seven-day period.

"With the bushfires that we're managing at the moment, this is a strong window to consolidate containment lines and black out fires so that the next hot weather event we get, whenever that may be, our fires are a lot more secure."

The EPA has issued a high level smoke alert for for Morwell and Traralgon for Saturday and Sunday as a result of bushfires.

Victoria's Chief Health Officer, Dr Rosemary Lester, said excessive smoke could aggravate heart or lung conditions, cause eye irritation, coughing and wheezing.

"Everyone should avoid prolonged or heavy physical activity and keep informed about fire activity in their immediate area," she said.

"Anyone with a heart or lung condition should take their medication as prescribed by their doctor. "People with asthma should follow their asthma management plan."

Anyone with concerns about their health should seek medical advice or call NURSE-ON-CALL on 1300 60 60 24.