There is, according to the weather bureau, more chill to come.

One senior forecaster offered a grim prediction for the rest of the week: "Coldest week of the year," Michael Efron told Fairfax Media.

A blunt message, perhaps, but best to be prepared for this kind of weather when city temperatures are planning to dip lower than the inside of your fridge.

Exceptionally low early morning temperatures this week are expected to hover at around the five degree mark.

The worst of the chill is expected to hit Melbourne on Thursday, when a powerful cold front is forecast to sweep through the city..

Before the cold change strikes, Thursday morning is expected to be full of rain.

The front will enter through the state's west before hitting Melbourne and causing hail and possible thunderstorms.

So far this week, icy records have already been smashed.

On Sunday, Melburnians rose to the coldest morning of the year, with the temperature in the city hovering at around 3.3 degrees.

Mildura – a town that's usually one of the hottest in Victoria – had its coldest day since 1989 on Sunday, with the mercury only inching up to 9.1 degrees.

On Monday temperatures in the metropolitan area failed to reach the forecast of 12 degrees, instead topping a chilly 10.4 degrees about 3pm, making it the coldest day of the year so far.

On Tuesday morning, city temperatures dropped to five degrees at about 3am.

In Essendon, there was a low of 5.7 degrees, 5.5 degrees in Geelong and 5.6 degrees in Scoresby.

A maximum of 15 degrees is forecast for Tuesday, with cloud cover keeping extreme cold at bay.

A top of 14 degrees is expected on Wednesday, yet there will be a higher chance of showers come Thursday and Friday.

Victorian ski resorts have reported small snowfalls in recent days, but the bureau is predicting more significant falls on Thursday and Friday.

"We are looking at relatively low level snow again, to 1100 or 1000 metres," Mr Efron said.

Snow won't fall as low as it did last Friday, he said, but areas such as Lake Mountain and even the Grampians should get a decent dusting on Thursday afternoon and evening.

Meanwhile, the Australian Red Cross blood service has revealed cold and flu symptoms are wiping out up to 1000 donors a day, placing enormous strain on existing donors.

"Around the country, we are seeing as many as 1000 people cancel their appointments every day, almost half of them due to illness," the service's Shaun Inguanzo said.

They are pleading for people with the universal O-negative blood type to donate, as reserves for that blood type slipped to just two days' supply.

Mr Inguanzo said they desperately needed new donors.

"O-negative is the universal type given to patients in emergency situations, when their blood type is unknown," he said in a statement.

He said maintaining O-negative supplies during winter was hard.

With Anna Prytz, Carolyn Webb