Australian Weather

29 Apr 2026, 1:04AM UTC

Melbourne, Adelaide and Hobart are all set to start May with maximums in the mid-to-high twenties that are around 10 degrees above the monthly average. All three cities – along with much of southeastern Australia – have experienced an unseasonable run of warmth in recent weeks, as high pressure systems centred over waters south of the mainland have blocked cold fronts from pushing northwards. That pattern looks set to continue for at least another four days in all three cities, before a slow-moving cold front starts to disturb the stable set-up during the weekend. Let’s take a quick look at Friday’s weather in each city: Image: Temperature anomalies for Australia on Friday, May 1, 2026. Source: Tropical Tidbits.  Melbourne Melbourne is having an exceptionally warm end to April, with maximums exceeding the monthly average of 20.2°C on 10 of the last 11 days of the month – and by three degrees or more on each of those days. But this week’s warmest day could be Friday, May 1, when the forecast maximum of 26°C would be nearly 10 degrees above the monthly average of 16.8°C. Adelaide Like Melbourne, the South Australian capital has had a very warm run recently. Since April 18, maximums have been well above average on every day except one, and that trend will continue until the end of the month this Thursday. Indeed, the five day period leading up to Anzac Day was Adelaide's warmest spell this late in the season in 105 years.  On Friday, Adelaide is expecting a maximum of 29°C. That would be more than 10 degrees above the average May maximum of 18.6°C.  Hobart Image: Parts of Tasmania will experience heatwave conditions — defined by the BoM as three or more days of unusually high maximum and minimum temperatures relative to the local climate and recent weather. Source: Weatherzone. Earlier this month, the Tasmanian capital shivered through a day which peaked at just 11.5°C as snow coated kunanyi/Mt Wellington.  A high of 25°C is on the cards for this Friday, which would be more than 10 degrees above the average May maximum of 14.6°C. What’s causing the unseasonable warmth over southeastern Australia? Image: Synoptic chart for Friday, May 1, 2026. Source: Weatherzone. As mentioned at the top of this story, high pressure systems have been blocking the cool, showery weather systems that lurk in the Southern Ocean. Friday looks to be the warmest day of the week across the southeast as air circulating anti-clockwise around the high centred near New Zealand drags warm air from the interior of Australia southwards. By Sunday and Monday, cooler, unstable weather should hit the southeast as the blocking high drifts east and the cold front pushes through. There’s also potential for a much colder outbreak around the middle of next week.

28 Apr 2026, 5:52AM UTC

Sea surface temperature observations from the past two weeks suggest that El Niño could be rapidly emerging in the tropical Pacific Ocean. Computer models have been hinting at the possibility of a 2026 El Niño event for the past three months, with the Bureau’s modelling predicting in January that El Niño could develop by winter. Things now appear to be moving faster than anticipated, with ocean temperatures in the tropical Pacific Ocean rapidly warming towards El Niño thresholds in the past couple of weeks. Ocean temperatures inside the key monitoring region for El Niño - an area known as the Niño3.4 region – have warmed rapidly this month, rising by 0.5°C in the last two weeks and 0.3°C in just one week. Image: Daily sea surface temperature anomalies in the tropical Pacific Ocean during the last 30 days, with the Niño3.4 region highlighted. Source: NOAA, annotated by Weatherzone. El Niño occurs when sea surface temperatures in the Niño3.4 region are warmer than average for several consecutive months. In Australia, the El Niño threshold is 0.8°C warmer than the long-term average (taking the background warming signal from climate change into account). The latest weekly Niño3.4 index value, measured in the week ending on April 26, 2026, was 0.23°C above average. Just two weeks ago this index was sitting 0.27°C below average and just over two months ago, it was at -0.87°C, below the threshold for La Niña. Image: Relative weekly Niño3.4 index during the last few years. Source: Weatherzone. A rapidly rising Niño3.4 temperature can be a sign that El Niño is emerging in the Pacific Ocean. However, this ocean warmth will need to intensify further and be sustained for several months to qualify as an official El Niño event. READ MORE: What does a 'super El Niño' mean for Australia's weather? Another important part of El Nino is the atmospheric response to the oceanic warming. For El Niño to become established in 2026, the ocean and atmosphere need to become coupled and reinforce each other. The atmosphere is starting to show signs of an El Niño pattern, with the 30-day Southern Oscillation Index (SOI) – a measure of atmospheric pressure difference across the tropical Pacific – dipping below –10 in the past week. This is well below the El Niño threshold of –7, however, these negative values will need to be sustained for at least several weeks to qualify as an El Niño signal. Furthermore, easterly trade winds over the western Pacific Ocean are weakening, which is another sign of a developing El Niño. It is too early to say that El Niño has arrived, but the ocean and atmosphere are showing clear signs that it could be rapidly emerging as we head into the final month of autumn.