With two weeks left of the 2026 Australia winter, springlike warmth will spread across large parts of the most heavily populated corner of the country.

While the coastal fringe of eastern Australia won’t feel particularly warm until the latter half of the week due to persistent showers with onshore winds, cities like Melbourne and Adelaide will come close to 20°C on Tuesday – with above-average maximums every other day this week.

Even Hobart will come close to 20°C this week, with a top of 19°C on the cards for Wednesday (average August maximum 13.2°C) while Canberra can expect tops of 17°C or 18°C from Wednesday right through until Sunday (average August maximum 14.4°C).

Because of the combination of a mild airmass and cloud, minimum temperatures are also likely to be relatively warm for winter across a broad area of the country for most of this week.

Strong high pressure: the first ingredient for warmth

A strong high pressure system was centred over Tasmania on Monday morning.

The mean sea level pressure near the high’s centre exceeded 1041 hPa (hectopascals) in parts of Tasmania during the mid-morning. The BoM states that “a typical high is around 1020 hPa or higher”. So when the mean sea level pressure is up in the 1040s, you’re looking at a very strong high.

Indeed, it was only a month ago that Australia registered a new provisional record for the highest mean sea level pressure, with a reading of 1044.5 hPa at the small central Tasmanian town of Ouse. Today’s high pressure system is not far off that.

How the strong high is fuelling the unseasonable warmth

Just like the above-mentioned record high pressure system in July, today’s high is also located further south than is typical for this time of year. That means it’s blocking influxes of cold air from reaching Tasmania or the eastern mainland.

The high is also helping to funnel mild maritime air onshore, as winds circulate anti-clockwise around it. Already, Melbourne and Adelaide are under the influence of northeasterly winds which will swing more northerly as the week progresses.

And as any local knows, northerlies usually mean warmer-than-average temperatures in any season.

While the high will drift east over the Tasman Sea during the week, it will deflect the cold front which is currently sweeping through SW Western Australia this Monday, pushing any significantly cold air well south of the continent’s southeast.

Not a great week for the snowfields

Last week we wrote that the Australian snow season had neared the one-metre mark in depth at higher elevations, but that warm weather this week would likely erode the snowpack.

That warm spell is now upon us, with maximums expected to reach as high as 6°C on at least two days this week at Thredbo Top Station – Australia's highest weather station at an elevation of 1957 metres.

If you’re reading this in northern Australia and six degrees seems like a cold maximum, remember that everything is relative in weather, and that the average August maximum for Thredbo Top Station is just 0.6°C.

The good news is that the 2026 snow season still has scope for improvement, with early signs of a snowy system next week. As ever, check the latest forecasts, snow cams and much more on the Weatherzone snow page.