Drought
Rainfall deficiencies and water availability

Below average rainfall across much of southern Australia, except Tasmania

September rainfall was below average (in the lowest 30% of all Septembers since 1900) for:

• for most of Victoria
• southern and central South Australia
• central and eastern Western Australia
• parts of the New South Wales and Queensland east coast
• areas in Queensland's interior
• areas in eastern Tasmania.

For Victoria and South Australia, area-averaged rainfall was 44% and 45% below September average respectively.

September rainfall was above average (in the highest 30% of all Septembers since 1900) for:

• much of western Tasmania
• much of the Northern Territory
• large parts of inland New South Wales and Queensland
• areas in north-eastern South Australia
• parts of western and northern Western Australia.

Further details: Monthly climate summaries, Latest National climate summary

July to September rainfall

July to September rainfall was below average (in the lowest 30% of July to Septembers since 1900) for:

• much of Victoria, particularly in the central region around Melbourne
• parts of southern New South Wales and eastern Tasmania
• small areas of the tropical north in Western Australia and the Northern Territory.

For Victoria overall, July to September rainfall was 20% below the 1961–1990 average.

July to September rainfall was above average (in the highest 30% of July to Septembers since 1900) for:

• coastal and western regions of New South Wales
• western coastal regions of South Australia and the north-east of the state
• the south and west of Western Australia
• parts of tropical north Queensland and the Northern Territory

Recent weather patterns

Throughout much of 2024 until June 2025, weather patterns across southern Australia were dominated by slow-moving high pressure systems contributing to persistent warm and dry conditions. During winter 2025 more typical cool season patterns of low pressure systems and fronts returned across southern Australia, however during September pressure was above average across Australia, except for Tasmania.

Maps: Recent and historical rainfall maps

Climate change

State of the Climate 2024 has indicated that there has been a shift towards drier conditions across southern Australia, especially for the cool season months from April to October. While some areas can have above average rainfall in some seasons, for southern Australia as a whole, April to October rainfall has been below the historical (1961–1990) average in 25 the last 31 years between 1994 and 2024.

The declining trend in rainfall is associated with a trend towards higher surface atmospheric pressure in the region and a shift in large-scale weather patterns. There have been more highs, fewer lows and a reduction in the number of rain-producing lows and cold fronts. Over the southern Australia region, there has been an increase in density, and therefore frequency, of high pressure systems across all seasons.

Long-range forecast for September to November

The long-range forecast, released on 2 October 2025 for October to December 2025 shows:

• rainfall is likely to be above average for much of the eastern half of Australia
• warmer than average days are likely across most of Australia, except in parts of eastern New South Wales
• warmer than average nights are very likely across much of Australia.

In recent weeks, the wet forecast signal for above average rainfall in October has weakened, while it has strengthened for November.

Deficiencies for the 9 months since January 2025

For the 9-month, year-to-date, period since January 2025, areas with severe or serious rainfall deficiencies (rainfall totals in the lowest 5% or 10% of periods, respectively, since 1900) extend across:

• north-eastern agricultural regions in South Australia
• much of the south, parts of north-western and central Victoria
• much of Tasmania, except areas in the east
• small areas in southern New South Wales.

Areas with lowest on record rainfall include:

• part of south-west Gippsland in Victoria.

Since August, rainfall deficiency areas have reduced in extent and severity in Tasmania and have mostly cleared in New South Wales. Rainfall deficiency areas have expanded in South Australia, Victoria and Western Australia.

Deficiencies for the 20 months since April 2023

For the 20-month period since February 2024, areas with severe or serious rainfall deficiencies (rainfall totals in the lowest 5% or 10% of periods, respectively, since 1900) extend across:

• agricultural regions of South Australia
• much of Victoria, except for areas along the northern border and east Gippsland
• parts of southern New South Wales
• part of western Tasmania, the Bass Strait islands and a small area extending to the east coast

Areas with lowest on record rainfall include:

• much of the agricultural areas in south-eastern South Australia, except in the far south-east
• most of south-west Victoria extending inland to the far north-west, and south-west Gippsland.

Compared to August, deficiency areas contracted or became less severe in Tasmania but expanded slightly in South Australia, Victoria and bordering areas in New South Wales.

Deficiencies for the 30 months since April 2023

For the 30-month period since April 2023, which also includes the previous two southern cool seasons, areas with severe or serious rainfall deficiencies (rainfall totals in the lowest 5% or 10% of periods, respectively, since 1900) extend across:

• areas in the west and south-west of Western Australia
• agricultural regions of South Australia
• south-western Victoria, south-west Gippsland and part of the north-east
• a small area of alpine New South Wales
• areas across Tasmania.

Areas with lowest on record rainfall include:

• parts of the Yorke Peninsula and Mid North district, and a small area near the south-east coast in South Australia
• the coastline from Warrnambool to Cape Otway in Victoria.

Since August deficiency areas have slightly contracted in Tasmania, but have slightly expanded and intensified South Australia and Victoria.

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Soil moisture remains below average in parts of the mainland south-east

September root zone soil moisture (0–1 m) was below to very much below average (in the lowest 10% of Septembers since 1911) in:

• parts of Victoria including the greater Melbourne region
• southern New South Wales
• the south-east of Tasmania
• areas of south-east Western Australia and inland South Australia
• parts of Western Australia's Gascoyne and Pilbara regions
• scattered areas of Queensland and the Northern Territory.

Areas of soil moisture deficits remained similar to August, with some expansion in parts of South Australia and western and northern Victoria. Rainfall in mid-September increased soil moisture in the southern New South Wales Riverina area and surrounds but declined again towards the end of the month.

Above average rainfall in western Tasmania increased the soil moisture during September. However, soils in this area are typically close to saturation at this time of year.

Rainfall in recent months in the south has not been sufficient to restore deeper soil moisture in most areas.

Low soil moisture for long periods of time is an indicator of agricultural drought, affecting ongoing crop growth, and the pasture growth required for livestock. During the southern winter cropping season low soil moisture can impact crop emergence, establishment and growth.

Evaporative stress remains elevated in the south-east

Evaporative stress for the 4 weeks ending 30 September 2025 was elevated (negative Evaporative Stress Index (ESI)) in:

• the south-east of the mainland
• south-eastern and central Queensland
• central parts of South Australia and the Northern Territory
• scattered areas of Western Australia.

During September, evaporative stress eased over Tasmania. The ESI also eased slightly in parts of the south-eastern mainland where it had been significantly elevated (below −2) but the area affected by evaporative stress expanded throughout most of Victoria and South Australia. South-eastern and central Queensland was also an area of developing evaporative stress during the month.

See this journal publication for further details on calculation and use of the ESI in drought monitoring.

Rainfall deficiencies and water storage at the end of September

• September rainfall was above average for western Tasmania, large parts of central Australia and much of the tropical north, and below average for much of southern and south-eastern Australia and parts of the east coast.
• Year-to-date rainfall deficiency areas have expanded in southern mainland states but have reduced in severity in Tasmania and mostly cleared in New South Wales.
• The extent and severity of long-term rainfall deficiencies has slightly increased in south-eastern states, except for some easing in Tasmania.
• Soil moisture in some parts of the south-east remains below average for this time of year.
• Streamflow was below average at many sites across southern Australia and central eastern Queensland, with some locations recording their lowest September streamflow on record.
• Some water storages in the southern and eastern states have declined by up to 50% compared to this time last year.

Low streamflow in south-eastern Australia

Streamflow was lower than average at 19% of the 903 sites with available data across Australia in September (based on records since 1975). These below-average flows were primarily associated with average to below average rainfall, which reduced soil moisture and runoff across many catchments. Regions with a high proportion of sites with lower than average streamflow included:

• the South East Coast (Victoria) drainage division (47% of 101 sites)
• the South Australian Gulf drainage division (70% of 10 sites)
• eastern areas of Tasmania (32% of 22 sites)
• the Murray–Darling Basin (28% of 340 sites), particularly throughout the southern half of the Basin
• some sites in central eastern areas of the North East Coast (10% of 167 sites), and two sites in the Carpentaria Coast drainage divisions in Queensland.
• few sites in the South West Coast drainage division of Western Australia (5% of 67 sites). A single site in the Pilbara–Gascoyne drainage division.

Very much below average streamflow (in the lowest 10% of years since 1975) was recorded at 2% of sites in September. These sites were concentrated in:

• western and central east areas of the South East Coast (Victoria) drainage division
• southern areas of the Murray–Darling Basin
• three sites in the South Australian Gulf drainage division
• four sites in the North East Coast drainage division and a single site in the Carpentaria Coast drainage division in Queensland.

Streamflow in September was around average at 43% of the 903 sites with available data, across the country.

Higher than average streamflow was recorded at 38% of sites, with 10% of sites observing very much above average streamflow (in the highest 10% of years since 1975). Regions with higher than average streamflow included:

• the Tanami–Timor Sea Coast drainage division (45% of 27 sites), and east and far west areas of the Carpentaria Coast drainage division (51% of 33 sites) and three sites in the Lake Eyre Basin (33% of 9 sites)
• the North East Coast drainage division in Queensland (44% of 167 sites)
• along the South East Coast (New South Wales) drainage division (84% of 112 sites) and sites in the northern Murray–Darling Basin (25% of 340 sites), particularly in the north-east
• across Tasmania (23% of 22 sites)
• the South West Coast drainage division of Western Australia (59% of 67 sites) as well as three sites in the Pilbara–Gascoyne drainage division.

This elevated streamflow was due to high rainfall in parts of eastern Australia and the west of western Australia in August, and increased soil moisture content and runoff in those catchments.

Low storage levels in southern Australia, the Murray–Darling Basin and central Queensland

By the end of September, total water storage across Australia—based on 306 public storages—was at 70.3% of capacity, a 2.2% increase from the previous month, but 5.1% lower than at the same time last year. Storage volumes declined in 138 storages during September, with relatively low levels observed in several regions, including:

• the southern and south-eastern Murray–Darling Basin
• Victoria, particularly in western areas
• central Tasmania
• central eastern Queensland
• the Harding storage in the Pilbara–Gascoyne drainage division
• Perth urban storages.

These declines generally reflected low inflows and maintenance of water releases during September in the affected regions.

North East Coast

Storage volume decreased in 60 of the 69 storages in the North East Coast drainage division in Queensland during September. Overall, storages across the North East Coast drainage division were at 71.8% of capacity at the end of September, a monthly decrease of 2.3% and slightly (0.2%) lower than at the same time last year.

Several storages remained below 50% of capacity at the end of September, notably Fairbairn and Lake Awoonga, Queensland’s second- and fourth-largest storages respectively.

Fairbairn decreased by 1.6%, finishing the month at 18.7%. The decline at Fairbairn contributed to reduced overall volumes in the Nogoa-Mackenzie system (18.7% full) in September, which supplies water to rural communities across central Queensland. Lake Awoonga also decreased by 1.2%, ending September at 31.3%.

South-eastern Australia

Many storages across the Murray–Darling Basin and South East Coast (Victoria) drainage division were below or close to 50% of capacity by the end of September, including Hume Dam, Australia’s seventh-largest reservoir, and Lake Eucumbene. Hume Dam increased by 3.9% during September, finishing at 55.8%.

The overall storage volume across the Murray–Darling Basin increased by 2.4% during September, finishing the month at 70.9%. The increase was largely driven by inflows to larger storages, while many smaller reservoirs and weirs experienced declines. It is typical for Murray–Darling Basin storage to increase this time of year, due to lower demand and increased inflows in the south. Despite the monthly increase, total storage in the Murray–Darling Basin remained 8.4% lower than at the same time last year.

Overall storage volume across the South East Coast (Victoria) drainage division increased by 4.4% in September, ending the month at 42.9%. In the Wimmera–Mallee system, a critical rural water supply for domestic and agricultural use in western Victoria, storages increased by 1.5%, reaching 42.6% by the end of September. However, this was 12.7% lower than at the same time last year.

In Tasmania, the two largest storages—Lake Gordon and Great Lake—were at 53.7% and 36.1%, respectively, by the end of September. Total storage across Tasmania was 65.5%, an increase of 8.4% from August, but 0.5% lower than this time last year.

Western Australia

Harding Reservoir, the only major storage in the Pilbara–Gascoyne drainage division, was at 20.8% of capacity at the end of September, a decrease of 1.2% from the previous month, and 5.0% lower than at the same time last year.

Urban storages

At the end of September, surface water storages supplying most capital cities were above 70% of accessible capacity, with the exceptions of Adelaide and Perth. Storages for both cities remain low, following an extended period of severe rainfall deficiencies reducing surface water inflows into regional storages.

Perth’s surface water storages were 46.0% full at the end of September, an increase of 3.3% from the previous month, but 1.9% down from the same time last year. The two largest storages supplying Perth remained below 40% capacity:

• South Dandalup at 10.4%
• Serpentine at 33.1%

The long-term decline in surface water inflows, driven by underlying climate change, means Perth now relies heavily on desalination and groundwater to meet urban water demand.

Adelaide’s storages were 62.8% full at the end of September, an increase of 5.6% from the previous month, and 12.2% higher than at the same time last year. The two largest storages supplying Adelaide remained close to 50%, with Kangaroo Creek and South Para reservoirs sitting at 53.5% and 50.7%, respectively. Adelaide’s urban water supply is augmented by transfers from the River Murray, with additional support from desalination and groundwater. River Murray pipelines also supply water to the Eyre and Yorke Peninsulas and parts of south-east South Australia.

In response to persistent rainfall deficiencies, the Victorian desalination plant has been in operation to support water supply to the Melbourne and Geelong areas.