Soaring 40C temps, cyclones to pound multiple regions of Australia as rare weather event unleashes chaotic summer

Millions of Aussies are in the firing line for a chaotic summer - amid forecasts of soaring temperatures, heightened flood risks and a dangerously active cyclone season looming over the country for the next six months. Australia is likely to receive its sixth consecutive wetter-than-usual severe weather season, which runs from October 2025 to April 2026, according to a report prepared by Sky News Weather senior meteorologists Alison Osborne and Rob Sharpe. Changing sea temperatures in the Indian Ocean have signalled a negative phase of the Indian Ocean Dipole (IOD), while cooling temperatures in the Pacific indicate another weak La Nina event arriving in late spring and lingering into summer. This dual event could be the first time since spring 2022 that a La Niña and negative IOD have coincided, contributing to Australia’s second wettest spring on record. With heavy rains forecast to drench the country well into next year, areas across the far north, east coast and south east of Australia are expecting a hotter than usual summer. The chances of above normal temperatures - including severe and extreme heatwaves - will rise from January 2026 as the potential for extra cloud and rain diminishes across Australia. The NSW coast may escape some of the extreme summer heat with an increase in wet weather, while the Northern Territory and Queensland are likely to cop the worst of it. An above average cyclone season (November to April) is also possible for the second year in a row with high-end severe tropical cyclones likely. The 2024-2025 cyclone season was unusually active, with 12 tropical cyclones formed in the Australian region - the most since 2006. However due to the negative IOD, possible La Nina and other climate change factors Sky News meteorologists believe between nine and 12 tropical cyclones are likely over Australian waters this cyclone season, with two to four likely to make landfall. The chaotic weather will kick off this week as a rare phenomenon triggers scorching 40C heat, destructive storms, heavy rainfall and 100kmh winds across different parts of the country. Sudden warming in the stratosphere above Antarctica is disrupting weather patterns in the southern hemisphere, causing a negative Southern Annular Mode (SAM). During spring, a negative SAM pattern typically brings cold fronts and heavy rains to southern Australia, while delivering warm and dry conditions to northern and eastern Australia. This chaotic weather event will bring heavy rains and damaging winds to southern states this week, while delivering warm and dry conditions to northern and eastern states. A cold front is currently moving eastwards across southern parts of Australia - including South Australia, Victoria and Tasmania - bringing damaging winds and heavy rainfall to those regions into Thursday. The Limestone Coast in southeast South Australia, parts of southern Victoria and much of western Tasmania could receive up to 80mm of rain in the coming days. The bureau has issued multiple flood watch warnings across Tasmania this week, with the coming rain due to hit already saturated catchments in the region and potentially cause riverine flooding from later today. The cold front will also deliver damaging wind gusts, up to 100kmh, to Victoria’s eastern alpine region and across the NSW Snowy Mountains through Wednesday evening into Thursday morning. In Melbourne and Adelaide temperatures are not likely to exceed 20C this week, with showers also likely on multiple days. By contrast the Northern Territory, Queensland and NSW will face unseasonably high temperatures this week, with maximum temperatures on Thursday forecast to reach 28C in Sydney, 35C in Brisbane and 40C in the Kimberley region. According to Weatherzone, the combination of heat and dry weather in northern and eastern Australia will also increase the potential for fires this week. High fire danger is likely over broad areas of Western Australia, the Northern Territory, Queensland and NSW.