Temperatures across the Kimberley have exceeded 40 degrees Celsius, setting a new all-time national record for winter.

The weather station at Yampi Sound recorded the record-breaking temperature, which reached 41.6C on Monday afternoon.

Once verified, it will surpass the old Australian winter high of 41.2C at West Roebuck in August 2020.

Other notable maximums in the region by 3pm WST included 40.6C at Wyndham, 40.7C at Derby and 40.2C at Kununurra, all station records for winter.

Across the NT border, Bradshaw reached 40.0C, which if confirmed will set a new NT winter record, passing 39.7C at Timber Creek in 2013.

Rare winter heat across northern Australia saw Monday's maximums exceed 40C.

While the absolute hottest temperatures on Monday were observed over the north-west, the greatest departures from normal were in southern Queensland, where Roma peaked at 34C, 11C above average for August.

Monday's national record follows a South Australian record on Saturday when Oodnadatta climbed to 39.4C, an incredible 3C above the previous highest winter temperature for the state.

Queensland came within 0.1C of a state record on Sunday when Birdsville reached 38.4C.

North-west heat to reach Queensland and NSW

The simmering hot air mass over the north-west of Australia will be driven across the interior this week to the east coast, leading to possible further winter records in parts of WA, the Northern Territory, New South Wales and Queensland.

Parts of the Kimberley may again exceed 40C on Tuesday and Wednesday.

Alice Springs' forecast high of 37C on Friday will pass its winter record of 35.2C from August 2009.

Sydney's heat should also peak on Friday when the maximum reaches 29C, just short of the city's winter record of 31.3C from 1995.

Newcastle is predicted to hit 29C on Wednesday and Friday, challenging its winter record of 29.9C from 1995.

Coffs Harbour is forecast to sweat through a high of 32C on Saturday, within reach of the city's winter record of 34C from 2009.

Brisbane's heat should peak on Saturday at 34C, a whisker off its record of 35.4C from 2009.

The early finish to winter is due to a lack of cold fronts reaching Australia from the Southern Ocean this August. That has allowed a hot air mass to build prematurely over the country's north.

Called the heat engine of Australia, this air mass has then expanded to southern states during the past fortnight and brought temperatures as much 17C above the August average.

The background influence of climate change is also playing a role in the surprise heat, enhancing an already unseasonably warm air mass and increasing the likelihood of record temperatures.

'Destructive gusts' linked to abnormal heat

While the north is baking, southern states are facing a week of wild westerly winds.

Warnings have already been issued for Tuesday across Tasmania and much of Victoria, with the risk of destructive gusts in excess of 125 kilometres per hour, equivalent to the force of winds in a category two tropical cyclone.

Dangerous winds will also spread to eastern NSW on Wednesday, with modelling indicating peak gusts could hit 120kph on the ranges.

Another burst of strong westerlies will quickly follow, starting in south-west WA on Thursday then spreading to south-east states on Friday. Again, warnings of damaging gusts are likely.

A third-round of gusty westerlies is likely through the weekend over Tasmania and Victoria.

The vigorous westerly flow is the result of an immense temperature difference between the unseasonably warm air mass over Australia and the regular winter polar air in the Southern Ocean.

This tight thermal gradient is leading to 200kph winds just 5 kilometres above the ground, sufficient to bring gales down to sea level.