A heavy thunderstorm swept across Melbourne, bringing damaging winds and dust to a city already struggling to cope with extreme heat.
Winds of 100km/h were measured near Melton and Werribee, and a severe weather warning was in place throughout the afternoon.
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Melbourne struggles through extreme heat
Paramedics were kept busy today rescuing children from locked cars despite numerous warnings about the dangers, as Melbourne's temperature soared.
The storm moved across the CBD about 6pm and northern suburbs by 6.30pm, with winds causing the city to be coated in dust.
Residents in Mildura, in Victoria's far north, also experienced significant dust storms.
Bureau of Meteorology senior forecaster Richard Carlyon said dry conditions had combined with strong winds to kick up the dust in the city when the cool change came through at 6pm. The dust storm lasted for about 10 to 20 minutes before a wind change moved through.
"It wasn't what you call a heavy dust storm," he said.
"I have seen some images from around Melbourne and certainly, there was some reduced visibility, but I think it was more of a blanket up over the north-west (of the state)."
Mildura, in the state's far north, was coated in dust just after 4.30pm with visibility down to 300 metres at the town's airport.
Mr Carlyon said the dust storm was nowhere near the intensity of an infamous one in 1983, when the city was enveloped, visibility reduced to 100 metres, and three airports closed.
"It was nothing like the early '80s," he said.
The severe weather warning was lifted for Melbourne at 8pm but remains in place for parts of eastern Victoria, with damaging winds still expected in Morwell, Traralgon, Sale, Moe, Bairnsdale and Orbost.
Life Saving Victoria closed a number of beaches between Fairhaven and Point Lonsdale on the Great Ocean Road during the afternoon due to lightning.
It caused a headache for emergency services, with the State Emergency Service receiving 236 calls for help by 6.45pm, mostly in Melbourne's eastern suburbs.
SES personnel are still working on 137 of those jobs and have resolved 99. Most were calls about fallen trees and building damage.Weatherzone: View the full weather satellite
The storm also caused widespread power outages across Melbourne and country Victoria. At 8pm, there were almost 1000 homes without power across the city.
Some of the worst-affected suburbs were Thornbury, where about 260 homes were without power in the vicinity of Smith Street and St George's Road, and at Cadow Street in Kew East, where 211 properties were affected.
Power was out to 124 homes near Appleton Street in Richmond, while parts of Carlton North, Port Melbourne and Sunshine West are also affected.
A CitiPower spokeswoman said they have had crews on stand-by given the weather predicted.
There are also outages to 158 homes in Geelong.
The thunderstorms hit as Melburnians faced a slow commute home, with scorching heat forcing speed restrictions across the city's train network.
Trains travelled at a maximum of 70 km/h across the entire network in the afternoon, pushing out travel times and forcing the cancellation of some services.
Metro spokeswoman Sammie Black said speed restrictions were enacted just after 2pm because it had reached 42 degrees at Laverton, in Melbourne's west.
Trains normally travel at speeds of up to 120 km/h in some parts of the network.
The restrictions were lifted by 7pm, but there were major delays on the Craigieburn, Werribee and Frankston lines well into the evening.
Metro has implemented a new extreme-heat strategy this year, which includes restricting speeds on individual lines to 80 kilometres an hour when tracks reach 55 degrees.
Waiting on that cool change
Melbourne had a relatively cool start on Wednesday, sitting at about 20 degrees during the morning commute.
But it warmed steadily through the day and reached 42.2 degrees in the city at 5.15pm. The mercury reached 43.8 degrees at Essendon Airport and Laverton.
Just before 8pm, the temperature dropped to a still sticky 33 degrees.
A second, stronger cool change will pass through the city overnight, said Bureau of Meteorology forecaster Peter Blake, pushing the temperature down by another 10 degrees.
Melbourne's forecast maximum on Thursday is only 19 degrees.
The heat has put firefighters on high alert and a total fire ban is in place in all districts except East Gippsland.
A watch and act warning is in place for St Helier and The Gurdies, near Phillip Island, for an out-of-control fire travelling south towards Stewarts Road.
Emergency Management Commissioner Craig Lapsley said the weather presented significant risks. He praised Victorians for "doing the right thing" and not putting themselves or others at risk.
He urged all Victorians to remain attuned to changing conditions, with dry lightning and a cool but strong wind change expected in the evening.
He added that emergency services were well prepared to respond to any drastic change in circumstances.
The Country Fire Authority has closed several parks in the Dandenong Ranges because of the severe fire danger rating.
Even some swimming pools couldn't handle the heat: classes were cancelled at the Fitzroy Pool due to the extreme temperatures and AquaPulse in Hoppers Crossing reached capacity about midday, with an hour-long wait to get in.