Source: The Conversation (Au and NZ)
Perisher snow cam Many parts of Australia have already broken early winter maximum and minimum temperature records. In southern Australia, Sydney and Melbourne had their warmest ever starts to winter. Daily observations show both cities experienced above-average June temperatures almost every day of the month.
Adelaide has also recorded above-average June temperatures in its first three weeks. Hobart and Canberra had mild starts to winter, with temperatures well above normal. So far, Perth is the only southern capital with typical June temperatures.
The world is experiencing a trend of unseasonably high temperatures driven by global heating, including the early summer heatwave in western Europe and parts of Asia. So, what can we expect for the rest of the winter season?
And does a warm winter have consequences for Australia’s next summer? The months ahead Abnormally warm conditions in Australia are likely to continue for at least the coming weeks, according to the Bureau of Meteorology’s seasonal outlooks.
Long periods of dry weather are likely, especially in late winter and spring, following the recent El Niño development. However, infrequent cold polar outbreaks still can impact southern Australia due to jet stream “waviness” south of Australia.
Here, waviness is the meandering of the air currents as they form the jet stream. If this occurs in a north-south direction instead of west to east, this can affect the movement of cold air and low pressure systems.
A poor 2026 Australian ski season has just started, and the outlook for sufficiently deep snow cover is unfavourable. However, just one or two unexpected heavy snowstorms can produce a major season turnaround. We’re part of a wider trend The seasons underway in Australia exemplify a worldwide trend of unseasonably high temperatures, including the early summer heatwave in western Europe.
Previously, extreme summer temperatures occurred later in the European summer, during July or August. But the present heatwave has produced record June maximum temperatures throughout Europe. On June 26, the United Kingdom’s hottest ever June day, temperatures reached 37.3°C.
The previous all-time UK June record was 36.1°C in 1976. During the heatwave, much of France, Spain, Italy and Germany reached or exceeded 40°C. Humidity levels have also been high. This unusually early and intense heatwave confirms climate extremes are the new normal.
Many nations are facing their warmest winters on record. The extreme heat is due to accelerated global warming since the 1990s, caused by human-made climate change. The United Nations predicts hot and cold extremes in nearly all inhabited regions with increasing global warming.
Our research, published earlier this year, confirmed this unseasonable warmth is due to the warming of Earth’s atmosphere and oceans. Global warming causes changes in large-scale southern hemisphere atmospheric circulation patterns. It also amplifies the impacts of known “climate drivers”, which are large-scale processes in the atmosphere and ocean that dictate weather patterns and climate variability.
We know the southern hemisphere jet streams, the fast-flowing, narrow bands of wind in the upper atmosphere, and associated storm paths, have shifted poleward. Once-reliable winter and spring rain-producing systems now often pass south of Australia.
Hence, southern Australia has been experiencing more high pressure systems. The result is cloudless skies and higher daytime temperatures. This is similar to the current heat dome in western Europe. Furthermore, Pacific Ocean temperatures off the Australian subtropical east coast are well above average.
Consequently, Tasman Sea high-pressure systems are directing warm, humid air over southeast Australia. This airflow means daily minimum temperatures are warmer than average. A record-setting Australian summer? You might be wondering whether Australia’s next summer will break heat records.
For now, the best answer can only be a firm “maybe”. Accelerated global warming is continuing, and clearly not confined to Europe. Recently, the eastern half of the United States issued an early summer heat dome warning.
Forecasters are warning southeast Australia to expect hotter, drier conditions in this El Niño year – a frightening combination that suggests record heatwaves, droughts and extreme bushfire danger are likely. Melbourne is particularly vulnerable to dry weather because of low dam levels.
Its catchment level (64% and falling) is the lowest since the Tinderbox Drought of 2017–19. Daily observational data shows Melbourne missed the rain that replenished Australia’s other southern capital cities in autumn and spring. Melbourne and its catchment are in the rain shadow of the Great Dividing Range, drying out the warm, humid subtropical air.
There is still a possibility Australia’s summer won’t break records. After all, an El Niño does not always generate extreme temperatures, dry conditions and fire weather. Also, the Southern Annular Mode – a climate driver that can influence rainfall and temperature in Australia – might bring more cold fronts.
Therefore, it’s possible that extreme heat might not take place in late spring or early summer.
But the way things are shaping up, it looks likely.
The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.
Original source: https://analysis1.mil-osi.com/2026/06/29/could-this-be-australias-warmest-winter-ever/