A late-season heatwave set a new Australian maximum temperature record for March on Sunday.

A stagnant mass of hot air is currently causing a low intensity-to-severe heatwave across a large swathe of central and western Australia. These are the lowest two categories on a three-tier scale of heatwave intensity.

Image: ECMWF-HRES model showing record-challenging March heat over central and western Australia on Monday.

While this type of heat is not uncommon in these parts of the country during summer, it's pushing the mercury to uncharted territory for this time of year.

On Sunday, Roebourne Airport reached 48.1 degrees. According to the Bureau of Meteorology, this is a new March maximum temperature record for WA and Australia as a whole.

The previous record for the month was 47.8 degrees, which occurred at Carnarvon Airport in 2007 and Roebourne in 1998.

Sunday was also the hottest March day on record at Port Hedland (47.0C) and Marble Bar (47.4C). Both of these locations have more than 100 years of historical records.

The hottest part of the air mass will be located further south and west on Monday. Maximum temperatures are forecast to reach 46-47 degrees over inland parts of WA's northern Gascoyne and western Pilbara districts, with some March records likely to be challenged once again.

The NT's Yulara Airport, near Uluru, also set a new March record on Sunday after reaching a top of 44.3 degrees. This was just 0.1 of a degree off the territory's March record of 44.4 degrees from Walungurru Airport during 2016, according to the Bureau. Yulara and Alice Springs Airport are forecast to reach 43 degrees on Monday. This would be a new March record for the latter, beating 42.5 degrees from 2015.

Temperatures will gradually drop across central and western Australia during the next few days as milder southerly winds push across the region.