Melburnians have woken to a frosty Friday morning – the third coldest in a decade.
Bureau of Meteorology forecaster Matthew Michael said minimum temperatures fell below four degrees in most parts of the city about 6am.
The eastern suburbs, however, felt the cold pinch more than others, with temperatures falling below freezing at Scoresby and Coldstream.
Laverton, in Melbourne's south-west, also experienced an uncomfortable 0.7 degrees.
Just last Thursday, residents woke up to a balmy spring morning of 19.7 degrees, only mildly colder than the hottest ever September Melbourne morning of 20.5 degrees in 1940.
Senior forecaster Scott Williams said such temperature differences in September don't happen very often.
"Most minimum temperatures this month have been above ten degrees, and this morning was the only one below 8 degrees," he said.
While the temperature should reach 19 on Saturday and 21 by Sunday, it is expected to be wet over the weekend, and well into next week.