Melbourne endured its coldest May day in 19 years on Wednesday.

The temperature at Melbourne's Olympic Park weather station had only reached a top of 10.6 degrees by 4pm on Wednesday.

If this maximum temperature isn't exceeded by 9am on Thursday, this will have been the city's coldest May day since 2000.

The mid-week chill is being caused by a large pool of cold air from the Southern Ocean passing across Victoria. In addition to this wintry air mass, cloud and showers also limited warming in Melbourne on Wednesday.

The air was even cold enough for snow to fall in Ballarat on Wednesday afternoon.

Snowed at school today just outside Ballarat pic.twitter.com/W7a3yuiNse

— Tony Shaw 📚 (@Maynardgcrabbs) May 29, 2019

Melbourne's coldest May day on record was 8.3 degrees, which occurred in 1977 and 1896.