Melbourne's all-time weather record has been broken and the city is sweltering under the twin effects of high temperatures and hot north-west winds.

The city hit 46.4 degrees at 3.04pm - the hottest day since the Bureau of Meteorology started keeping records 150 years ago.

The previous record was 45.6, set on January 13, 1939 - a day otherwise known as Black Friday.



"I've got a massive spreadsheet here of maximum temperatures and it doesn't mean anything any more. The whole thing's gonna have to be rewritten," BoM senior forecaster Terry Ryan said.

"Most places around the state will break all-time records."

