Australian Weather

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.

28 Apr 2026, 1:34AM UTC

A vast part of the continent will see much warmer temperatures than average for mid-autumn throughout the working week, as a broad area of high pressure dominates Australia’s weather pattern. The main exception is the southwest corner of Western Australia, where a trough has generated showers overnight, while a cold front will arrive on Thursday. That cold front will slowly push east, however it won’t impact the eastern states until the weekend, with significantly above-average maximum temperatures for this time of year at most locations from Tuesday through to at least Friday. Let’s break down the situation state by state, moving from west to east. Western Australia Perth had a wet Monday afternoon, with 8mm in the gauge in the 24 hours to 9am Tuesday. That rain should mostly clear this Tuesday, however a coolish maximum of 19°C is expected as a feed of high cloud from the northwest keeps a lid on warming. Temperatures will rise into the low twenties on Wednesday and Thursday ahead of the cold front due later on Thursday night. Image: Combined satellite and radar loop showing the feed of high cloud over large parts of WA on the morning of Tuesday, April 28, 2026. Source: Weatherzone. Northern Territory It will be business as usual for this time of year in Darwin, with a dry spell to cap off the last few days of the official 2025/2026 Top End wet season. Darwin can expect maximums around 33°C all week, which is close to the average April maximum of 32.8°C.  Alice Springs can expect maximums close to the April average of 28.4°C all week, although the mercury should rise to around 31°C on Saturday, May 2. That will be around eight degrees above the average May maximum of 23.1°C. South Australia Adelaide slightly exceeded its average March rainfall and is within a few millimetres of its average April rainfall after a desperately dry summer, but rain is still very much needed in the SA capital. The good news is a wet spell could arrive with much cooler air this weekend. Before that, expect a dry, very warm week for late April. Adelaide’s average April maximum is 22.2°C while its average May maximum is 18.6°C, but maximums will be around 28°C or 29°C from Wednesday through to Saturday. Most other parts of South Australia will also be unseasonably warm for most of the working week. Image: Temperature anomalies across Australia on Saturday, May 2, 2026, showing the sharp contrast as cool air pushes through the southwest into SA. Source: Tropical Tidbits.  Queensland Some parts of Queensland’s interior will reach maximums that are around two or three degrees above average for much of the week, although the southeast corner, including Brisbane, is one part of the state where temperatures will be close to average all week. Victoria Another warm week is in store for Melbourne and most of Victoria as the high pressure system centred over southeastern Australia drags warm air southwards from the interior of the continent. Melbourne can expect maximums in the mid-twenties from this Tuesday through to Sunday, in a pattern similar to last week, when Melbourne saw a run of six days when maximums were between 3 and 6 degrees above the average April maximum of 20.4°C. If Melbourne reaches its forecast maximum of 27°C this Friday, May 1, that would be just over 10 degrees above its average May maximum of 16.8°C. Image: Daily forecast for Melbourne, Vic, on the Weatherzone app. New South Wales/ACT Sydney has had a dry April by its standards, with just 30.8mm of rainfall received to date compared to the monthly average of 127.5mm. Mostly dry conditions should persist until the weekend, with maximums around 24°C or 25°C. The average April maximum is 22.6°C. Canberra will continue its recent pattern of cool nights with minimums of 5°C or lower, while days rise to 22°C or 23°C, which is a degree or two warmer than the average April maximum of 21.0°C.  By this Friday, May 1, some locations in western NSW could see May warmth records threatened. For example, the small town of Ivanhoe has a May high temperature record of 29.2°C, with a high of 29°C forecast for both Friday and Saturday.  Tasmania After a cooler start to the week than the mainland capitals with maximums in the teens on Tuesday and Wednesday, Hobart will have a four-day warm spell with maximums between 23°C and 25°C from Thursday through to Sunday. Given that Hobart’s average May maximum is just 14.6°C, Saturday could be more than 10 degrees above average. The rest of Tasmania also looks to be in for some unseasonable warmth.