Despite the temperature hovering around 10 degrees, 50 km/h winds and 70 per cent humidity have pushed the apparent temperature – basically a wind chill index –  below freezing in the CBD and northern suburbs.

In the CBD, for example, the apparent temperature is - 1.5 degrees, in Essendon -1.6 and at the airport -1.0.

"I haven't noticed it (apparent temperature) this low in the afternoon before," said Bureau of Meteorology senior forecaster Terry Ryan. "But we probably get these conditions a couple of times per winter."

Apparent temperature was measured on the basis of how cold exposed skin felt, said Mr Ryan, and is calculated using a formula mixing "normal" temperature, humidity and wind speed.

It's been chilly the entire day. The city recorded an apparent temperature of 1.3 just before 7.30am, with winds about 33km/h. The normal temperature at the time was 8.5 degrees.

At Melbourne Airport, the apparent temperature was -3.3 at 7.25am, with winds at 52km/h. (They were 70km/h at 5.53am.) It reached a frigid -4.6 at 11.30am, despite a normal temperature of 8.5.

Unfortunately records of apparent temperature are not kept, said Mr Ryan, but he said it was Melbourne's coldest weekend since July 20 and 21, when maximum temperatures were 9.7 and 11.1.

Today's wintry blast comes in stark contrast to Thursday, which had apparent and normal temperatures above ten degrees thanks to some winter afternoon sunshine.

There’s been a little rainfall, but not much. The highest metropolitan falls coming at Craigieburn, with 4.6 millimetres between 3am and 6am. At Essendon Airport and Warrandyte, 3.6 mm fell and there was 3.4 mm in Ringwood.

After starting the year strongly, Melbourne's water catchments – at 72.9 per cent – are a tad lower than they were this time last year. Still, they are much higher than they have been over the past decade.

The showers are expected to continue until Saturday afternoon, which is expected to be a much warmer day with a top of 18.

Sunday should be mostly sunny, with a high of 17. Northerly winds are tipped to reach  35km/h.

Next week will be wet, with storms and hail on Monday and Tuesday. Winds will also be strong next week, with north-westerlies expected to reach up to 45km/h by Thursday.

♦ A huge tree is in danger of collapsing onto Toorak Road, causing traffic chaos and tram services to be diverted.

The 80-metre tree, located at 546 Toorak Road, became uprooted this afternoon during heavy winds.

It is expected to fall between Kooyong Road and Orrong Road.

VicRoads is advising drivers to avoid the area.

Yarra Trams is diverting its Route 8 Moreland-Toorak tram via Commercial and Malvern roads in both directions.

SES spokesman Lachlan Quick said emergency services volunteers were at the scene.

The uprooted tree was one of about 140 Victorian incidents the SES had been called out to by Friday evening.

"A majority have related to trees down onto roads… there has also been some significant damage to power lines," Mr Quick said.

Kristian Silva