Victorian smokers are being urged to give up cigarettes as authorities make a fresh appeal to reduce the threat of fires being sparked.

Firefighters have joined the call for smokers to quit cigarettes, citing not only health risks but the threat of sparking a blaze.

Just after Christmas, five people were lucky to escape a Melbourne property fire, started by a cigarette, the Metropolitan Fire Brigade reported.

On average crews attend more than 10 fires a month across Melbourne caused by cigarettes, chief officer Dan Stephens said on Friday.

"Careless disposal of smoking materials can quickly start a fire, especially in a high-risk area like on a balcony, in a street bin or near grass and parklands," he said.

"On a hot or windy day, these fires have the potential to spread quickly and cause substantial damage to property and can put lives in danger."

The warning comes as Melbourne is set to soar to 33C on Friday while Swan Hill, in the state's north, is expected to hit 39C.

Quit Victoria director Sarah White said poorly-discarded cigarettes had the potential to spark devastating bushfires and the best solution was to stop smoking.

Estimates show smoking-related fires cost the state economy about $28.6 million a year, she added.

Smokers are encouraged to use heavy, high-sided ashtrays to reduce the risk of spreading sparks.