October heat records are being challenged in parts of southern Australia today.

Hot air from central Australia will be pushed across the nation's southern states on Thursday and Friday ahead of an approaching cold front.

Being at what is usually the hotter end of the month, some October heat records could be challenged on Thursday.

Adelaide had already hit 35 degrees by 1pm and could reach the high thirties during the afternoon. Prior to today, Adelaide's highest October temperature on record was 39.0 degrees in 1987. Friday could get to the low thirties, although cloud and showers accompanying a cool change should limit heating later in the day.

Melbourne climbed above 30 degrees shortly after midday and is forecast to reach 35 degrees on Thursday afternoon. This would be the city's hottest day since March, but a couple of degrees below the October record of 36.9 degrees from 1914. Friday could get almost as warm, with a top of 34 degrees forecast in the city.

Hobart could edge above 30 degrees on Thursday and 31 degrees on Friday, which would be the city's warmest pair of days on record this early in spring.

The timing of this hot weather could also make this the hottest halloween on record for some areas. These were the heat records for October 31 prior to 2019:

Adelaide 39.0C in 1987

Melbourne 33.1C in 2009

Hobart 34.6C in 1987