The warning comes as emergency services brace for a heatwave this week, with temperatures tipped to reach 40 degrees or higher from today until Thursday.

"Arsonists are responsible for a significant proportion of bushfires, some of which have ended in tragedy and the community has a part to play in stopping them," Mr O'Donohue said.

"There must be a zero-tolerance approach to deliberately or recklessly lit fires in our state, which means taking action to catch arsonists before their criminal behaviour has devastating consequences."

The annual Crime Stoppers Bushfire Arson Campaign raises awareness of bushfire arson in Victoria and urges people to speak up if they have concerns about possible bushfire arson.

"In some cases, members of the public are aware of a piece of crucial information that can help solve crimes," Mr O'Donohue said.

Department of Environment and Primary Industries Wimmera district fire manager Russell Manning said arson and machinery were the more common causes of fires last summer.

He said the community needed to work together to help minimise fire risks.

Mr Manning said 2012-13 was a busy season, with 4400 bush and grassfires across the state.

"In the Wimmera, we had a record 102 fires and 13 total fire ban days," he said.

Victoria Police crime statistics show there were 55 offences of intentionally causing a bushfire in 2012-13, up from 32 offences the previous year.

"The seriousness of bushfire arson crime cannot be understated and Victoria has some of the toughest penalties in Australia for bushfire-related offences," Mr O'Donohue said.

"Bushfire prevention is the responsibility of all Victorians."