The hottest day in 12 months is forecast for this Saturday, with temperatures expected to rise to a sweltering 41 degrees across Melbourne.
The surprise scorcher will follow a week of pleasant weather in the mid 20s and cool southerly breezes.
The forecast was upgraded from 39 degrees to 41 degrees on Monday afternoon.
The weekend's heat spike will be triggered by a build up of heat inland, which will be pushed across the country on Friday night by strong northerly winds.
Alice Springs is currently experiencing a week of high 30s, which will reach Melbourne on Saturday morning.
Winds are expected to reach a top speed of 31 km/h just after midday.
Bureau of Meteorology senior forecaster Dean Stuart said the temperature could rise to 40 degrees in some suburbs, but advises that the day will be followed by a cool southerly change.
"The afternoon will provide a welcome relief from the heat," Mr Stuart said.
The cool change is expected to reach the coast at around 4pm, arriving in Melbourne between 5pm and 6pm.
Despite the fierce winds and heat, no fire weather warnings have been issued yet, and there is currently no fire ban in place.
While the day will be the hottest in 12 months, Mr Stuart notes that days such as these are not unusual for early January.
In 2017, the highest recorded temperature was 38 degrees on January 17.
In true Melbourne fashion, we'll get more than one season in a day, and a big change on Sunday. A mild top temperature of 22 degrees is expected on Sunday, with a slight chance of rain.