Tropical Climate Update

Australian region

Recent conditions

For the fortnight ending 24 August, maximum temperatures across northern Australia were generally up to 4 °C above average, except for southern parts of the Northern Territory extending into Western Australia and coastal parts of north-eastern Queensland where maximum temperatures were up to 2 °C below average.

Minimum temperatures for the fortnight ending 24 August were generally 2 to 4 °C above average with minima reaching up to 8 °C above average for eastern parts of Western Australia, western parts of the Northern Territory, and the Territory's south-east extending into Queensland. Minimum temperatures were below average for small areas in eastern and central Queensland.

For the fortnight ending 24 August, there was little to no rainfall across most of northern Australia. However, parts of the southern Northern Territory, Western Australia's interior and north-eastern coastal Queensland, recorded up to 50 mm during the fortnight.

Long-range forecast

The long-range forecast for September to November, issued on 20 August, indicates above average rainfall is likely for much of the western half of northern Australia, extending into north-western Queensland, and below average rainfall is likely along parts of the eastern coastal fringe and Cape York Peninsula in Queensland. This season marks northern Australia's transition to the wet season. Early in the season, rainfall often remains low across much of the north, with less than 10 mm typically recorded in September.

Maximum temperatures for September to November are likely to be above-average across the southern half of northern Australia, and below average for north-eastern areas of tropical Queensland and the northern Kimberley in Western Australia. Minimum temperatures are likely to be above average across most of northern Australia.

Northern Rainfall Onset

The northern rainfall onset outlook provides probabilistic forecasts for the first significant rains after 1 September for the 2026–27 wet season. The northern rainfall onset for the 2026–27 season is likely to be later than normal for eastern and far northern parts of northern Australia and for parts of the north-west coastline, but an earlier onset is mostly favoured elsewhere across northern Australia.

Madden–Julian Oscillation

The Madden–Julian Oscillation (MJO) is currently weak or indiscernible. Forecasts as at 22 August show it is most likely to remain weak over the coming fortnight.

Tropical wind and cloudiness have been strongly influenced by El Niño since May, with westerly winds and increased cloudiness dominating the western to central tropical Pacific, and decreased cloudiness across the Maritime Continent.

International Conditions

Heavy rainfall in Japan and South Korea

On 13 August, eastern Japan, particularly the Chiba Prefecture, experienced a heavy rainfall event. Chiba City observed a daily total of 367.0 mm, three times its average August rainfall, with 115 mm recorded in one hour. The rainfall caused extensive urban flooding, landslides, power outages and transport disruptions with reports of fatalities. This event was driven by highly unstable atmospheric conditions that resulted in thunderstorms and intense convective rainfall.

Between 15 and 17 August, a low-pressure system directed moist air from the East China Sea towards South Korea bringing heavy rainfall especially to the country's south. Some areas in the south-east had three-day rainfall totals up to 800 mm (approximately 90% of the region's July-August average rainfall). Heavy rainfall resulted in flooding, landslides and transport disruptions. This event was associated with abundant tropical moisture from remnants of typhoons Dolphin and Chan-hom.

Typhoon Saudel

Typhoon Saudel (Obet) developed on 19 August east of the Philippines and rapidly intensified to typhoon strength by 21 August. It is forecast to continue tracking north-westwards across the Philippine Sea and strengthen further as it passes north of Taiwan.

Tropical Storm Narra

A slow-moving tropical depression over the Gulf of Tonkin intensified into tropical storm Narra on 21 August and continued to strengthen over the subsequent days. By 24 August, it was about 150 km east of Hai Phong, Vietnam, affecting northern Vietnam and south-eastern China. Narra is forecast to make landfall in southern Guangxi, China, on 27 August, then gradually weaken into a tropical depression. The system caused widespread heavy rainfall, flooding, landslides and property damage across northern Vietnam as well as flooding in China's coastal areas.