From 11:59pm tonight to 11:59pm on Wednesday, all of Victoria will re-enter stage four restrictions.

There will only be four permitted reasons to leave the home: shopping for essential items, essential work, permitted education that cannot be done from home and exercise for up to two hours a day with people from your household.

"This is going to be tough period for some - mentally, functionally, and for so many hospitality businesses that were just finding their rhythm again," Kealy said.

"Please look after yourself and each other, and don't hesitate to share your thoughts and feelings with a mate or professionals. It will help and give you some control back."

EXPLAINER: What are the impending stage four restrictions?

Premier Daniel Andrews said the drastic measures were needed to prevent a third wave of COVID-19 infections, rather than to respond to one.

He acknowledged there was no evidence of any cases in regional Victoria

"And that's how we want to keep it," Mr Andrews said.

"I don't want this thing to go from Melbourne to regional Victoria."

The Holiday Inn outbreak has grown to 13 cases and brings the total number of exposure sites listed on the Health Department's website to 30.

MAKING NEWS TODAY:

Regional Victoria has been included in the lockdown to keep cases out, according to Mr Andrews, as there would be no time to effectively set up a 'Ring of Steel'.

"If this was a longer term proposition we would appropriately differentiate (regional areas)," he said.

"My message to regional Victorians is we have no evidence of any regional cases and that's how we want to keep it."

Did you know you can receive updates straight to your inbox? To make sure you're up-to-date with news from across the region, sign up below.