Australian Weather

Today, 1:03AM UTC

Tropical moisture has made its way all the way south to Tasmania, delivering some of the state’s heaviest daily rainfall totals on record for May. In the 24 hours to 9am Thursday, notable readings included: 222mm was recorded at the rural locality of Gray, a few kilometres inland from the state’s east coast near the town of St Marys. This was the 4th-wettest May day on record at any Tasmanian site. 134.6mm was recorded at kunanyi/Mt Wellington above Hobart, with heavy rain falling steadily throughout the 24-hour period. 124.2mm fell at St Patricks Head, just north of Gray. 122.6mm collected in the rain gauge at Longley, a rural locality on the southern flank of kunanyi/Mt Wellington. Hobart also didn’t miss out, with 25.6mm in the Tasmanian capital. While this was considerably less than many other Tasmanian locations, it was still the city’s heaviest daily rainfall total in 10 months. Image: 12-hour radar and atmospheric water vapour loop over Tasmania to 3am on Thursday, May 28, 2026 (AEST). Source: Weatherzone. Why such heavy rainfall in Tasmania? As Weatherzone meteorologist Ben Domensino wrote on Wednesday, moisture streaming in from the Tasman Sea was heading directly towards Tasmania from the northeast, in a meteorological phenomenon known as an "atmospheric river". While the most intense phase of this event was relatively short lived, the moisture influx was still extreme enough to generate huge rainfall totals. Image: Modelled precipitable water (a measure of atmospheric moisture) and 850 hPa winds at 10 am AEST on Wednesday, May 28, showing the moisture-laden air from the northeast that inundated eastern Tasmania overnight. Source: Weatherzone. A moderate flood warning is currently in place for Tasmania's South Esk River. The river empties into the sea near Launceston and is famous for being Tasmania’s longest river (at 252km, just beating the Derwent, which empties into the sea at Hobart). While Launceston itself saw only 10mm in the 24 hours to 9am Thursday, the South Esk rises in the elevated terrain of the Ben Lomond Plateau, close to the east coast weather stations which saw rainfall totals of well over 100mm overnight – hence the current elevated river level. Why did kunanyi/Mt Wellington receive so much more rain than Hobart city? The 25.6mm that fell in downtown Hobart was only 19% of the 134.6mm that fell up on the mountain. The discrepancy was due to the orographic effect, where air rises and cools as prevailing winds drive it into a mountain or mountain range. This cooling typically causes heavy precipitation, as cool air can’t hold as much moisture as warmer air. It is of course very common for kunanyi/Mt Wellington to receive much more rainfall than Hobart city. Usually, that happens in westerly systems, when only light showers fall in Hobart as the air dries out on the leeward side of the mountain. On this occasion, the system came from the east and northeast, so while Hobart got a very handy soaking, the mountain got a much bigger one. Image: Average Tasmanian rainfall for May, showing how eastern areas are usually much drier than the rest of the state. Source: BoM. What next for Hobart? While easterly showers continue on Thursday morning in Hobart with a further 1.6mm in the gauge between 9am and 11am, only a light shower or two is expected in coming days, as winds swing to cooler westerlies more typical of the season as the weekend progresses.

27 May 2026, 1:11AM UTC

Right on cue for the start of winter, a series of cold fronts will deliver a week of consistent showery weather for Perth and southwest WA, with light showers already scooting through the region on Wednesday morning and heavier rain likely to commence this afternoon or evening. While much of eastern Australia has been unseasonably wet and mild this week as a complex series of troughs and upper and lower level low pressure systems interacts with a tropical moisture feed, the southwest can expect a classic winter pattern with repeated cold fronts. Image: Satellite and radar image at 8:30am (AWST) on May 27, 2026, showing a large cloudband with only light shower activity at this stage. Source: Weatherzone. Statistically, the coming rain is overdue May is typically Perth’s fourth-wettest month, with an average rainfall of 85.5mm. To 9am this Wednesday, May 27, the WA capital has had a relatively dry month, with only two rain days and a total of just 11.8mm recorded in the city. Clear skies tend to bring cool nights, which is why Perth’s running average minimum for May 2026 is around two degrees down on average. That includes Perth’s lowest May temperature in seven years on Sunday morning, when the mercury fell to 2.5°C. How much rain is likely in the next seven days? The 7-day predicted rainfall chart (below) reveals a purple zone around Perth, indicating 100mm or more in total. That would be around the upper limit of accumulated rainfall associated with the coming systems.  Image: Predicted accumulated rainfall totals for southwest WA for the seven days to Tuesday, June 2, 2026, according to the ECMWF model. Source: Weatherzone. But it appears likely that Perth could see falls in the vicinity of 10 to 20mm later this Wednesday with a similar range expected on both days this coming weekend. Lighter totals are expected on Thursday, Friday, and early next week. Thunderstorms are also a possibility in the southwest this evening, which would obviously cause some heavier rainfall totals over a relatively short duration at some locations. Will it get significantly cooler? The first front doesn’t have a particularly strong bite to it in terms of air temperatures, but the weekend system will definitely drop daytime temperatures by a few degrees, especially in the new week. Perth is expecting maximums a degree or two below the May average of 22.5°C from Thursday through to the end of the month on Sunday, then maximums of 18°C next Monday and Tuesday (June average 19.5°C). But the main story is the wet weather, which is always welcomed by most locals at this time of year.  In 2025, Perth exceeded its average monthly rainfall in June, July, August and September – the first time that had happened in all four months for 18 years. There won’t be too many arguments if it’s similarly wet this winter.