Drought
Rainfall deficiencies and water availability

Below average rainfall in the south and parts of inland Australia

Rainfall was below average to very much below average (in the lowest 10% of Octobers since 1900) for:

• most of Tasmania
• western and eastern Victoria
• south-eastern New South Wales, areas along the ranges and in the west
• large areas of Queensland, particularly in the south
• most of south-western Western Australia
• small areas of south-eastern and northern South Australia
• areas of inland Northern Territory.

Rainfall was above average to very much above average (in the highest 10% of Octobers since 1900) for:

• much of Western Australia
• parts of western South Australia
• areas in the north of the Northern Territory and Queensland
• scattered areas in eastern mainland states and along the east coast.

October was the first month of the northern wet season. Parts of south-east Queensland have had a later than average northern rainfall onset.

Long-range forecast

The long-range forecast released on 7 November 2024 for December 2024 to February 2025 shows:

• rainfall is likely (60 to 70% chance) to be below average for parts of the west of Western Australia, including some regions in the Central Wheat Belt district
• rainfall is likely to be within the typical range for the season for most of Western Australia, South Australia and the Northern Territory, south-eastern Queensland, including Brisbane.
• rainfall is likely to be above average for much of eastern Australia, including much of Queensland, New South Wales, Victoria and eastern Tasmania

• warmer than average days and nights are likely to very likely across most of Australia.

Long-term trends

State of the Climate 2024 reported there has been a shift towards drier conditions across the south-west and south-east of Australia, especially during the cool season months of April to October. There has been a decline of around 16% in April to October rainfall in the south-west of Australia between 1970 and 2023, compared to 1900–1969. It is highly unlikely that a decline of this magnitude could have occurred due to natural variability alone. Since 1994, average April to October rainfall in the south-east has been around 9% lower than it was in the 1900–1993 period. This decline has persisted even after the Millennium Drought of 1997–2009.

Deficiencies for the 9 months since February 2024

For the 9-month period since February 2024, severe or serious rainfall deficiencies (rainfall totals in the lowest 5% or 10% of periods, respectively, since 1900) extend along:

• small areas of the south coast of Western Australia
• agricultural regions of South Australia into western Victoria
• coastal South Gippsland in Victoria and the north-eastern ranges into southern New South Wales
• coastal north-west Tasmania, King Island and the Tasman Peninsula.

Areas with lowest on record rainfall include the Eastern Eyre Peninsula, York Peninsula, Murraylands and Upper South East districts in South Australia.

Compared to September, areas of rainfall deficiency expanded along the southern coast of Western Australia, but reduced in intensity in parts of south-eastern South Australia and Victoria.

Deficiencies for the 15 months since August 2023

For the 15-month period since August 2023, areas with severe or serious rainfall deficiencies (rainfall totals in the lowest 5% or 10% of periods, respectively, since 1900) extend along:

• small areas in the north-west of Western Australia and extending inland along the south-west coast
• agricultural regions of South Australia
• south-west Victoria and a region of north-eastern Victoria and southern New South Wales
• the north-west and coastal fringes around much of Tasmania including Bass Strait islands.

Areas with lowest on record rainfall include a small area around Albany in Western Australia, isolated areas near the south-east coast of South Australia including Kangaroo Island, and coastal western Victoria.

Compared with September, in Western Australia rainfall deficiency areas expanded slightly in the south-west. In south-eastern Australia, rainfall deficiency areas remained similar in extent, however areas with lowest on record rainfall in South Australia and Victoria contracted slightly.

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Below average soil moisture in the southern mainland

October soil moisture deficiencies continue in the southern mainland, with below to very much below average soil moisture in:

• most of Victoria into south-eastern New South Wales
• south-eastern and central western South Australia
• central southern Western Australia
• parts of western Queensland and small areas of the Northern Territory.

While October rainfall remained average to below average over much of southern Australia, the totals were sufficient to ease the severity of soil moisture deficiencies, particularly in the south of South Australia and western Victoria. Soil moisture deficiencies in south-west New South Wales contracted to a small area.

Below average rainfall through much of Queensland expanded soil moisture deficiencies into the inland south and north of the state.

Agriculture in southern Australia relies on higher cool season soil moisture. Low soil moisture for long periods of time affects crop growth and is an indicator of agricultural drought

Severe evaporative stress in large areas of southern Australia

Evaporative stress for the 4 weeks ending 31 October 2024 was elevated (negative Evaporative Stress Index (ESI)) in:

• most of inland Queensland and south-eastern Northern Territory
• parts of western and south-eastern New South Wales
• most of Victoria and Tasmania
• much of South Australia
• parts of the west coast and south of Western Australia.

Vegetation moisture stress decreased in most areas compared with September, notably in the south-west of Western Australia and parts of the south-east where ESI values had been significantly elevated (less than −2) over large areas. However, evaporative stress increased in parts of southern Victoria, Tasmania and the south coast of Western Australia where October rainfall was below average.

The ESI represents the influence of a combination of meteorological and land factors on drought conditions. A negative ESI indicates vegetation moisture stress linked to agricultural and ecological drought.

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

Rainfall deficiencies and water shortage at the end of October

• October rainfall was below average for most of Tasmania, western and eastern Victoria and large parts of New South Wales, Queensland, south-western Western Australia, and small areas of south-eastern and northern South Australia and southern Northern Territory.
• Recent rainfall deficiency areas expanded along the southern coast of Western Australia but reduced in intensity in parts of south-eastern South Australia and Victoria.
• Soil moisture remains below average in southern Australia and western Queensland, but the severity of deficiencies has eased in much of the south.
• Streamflow was low at a large proportion of sites in southern Australia including Tasmania and central Queensland.
• Some water storage levels were low in the west of Western Australia and in central Queensland. Many storages in south-eastern states were 10 to 50% lower than the same time last year.

Low streamflow in southern Australia and central Queensland

In October, higher than average streamflow (based on records since 1975) was observed at 21% of the 892 sites with available data. These were mostly in northern and eastern Australia. Very much above average streamflow (highest 10% of years since 1975) was observed at 4% of sites, including 1% of sites with highest on record, mainly in the Northern Territory and Queensland and some sites in north-east coastal New South Wales due to wet catchment conditions.

Lower than average streamflow was observed in October at 29% of sites. These were mostly associated with below average rainfall and dry catchment conditions. These were observed in:

• Victoria (59 % of 103 sites)
• South Australia (80% of 10 sites)
• central and southern areas in Queensland (14% of 150 sites)
• south-west of Western Australia (48% of 76 sites)
• Tasmania (52% of 21 sites).

Very much below average streamflow (lowest 10% of years since 1975) was observed at 2% of sites, mainly in western Victoria, South Australia, the Murray–Darling Basin, scattered sites in Queensland, southern Tasmania and the south-west of Western Australia.

October streamflow was average at 50% of sites, spread across Australia.

Low storage levels in the west of Western Australia, Southern Australia and Central Queensland

By the end of October, the total water storage in Australia (across 306 public storages) was at 73.8% of capacity, slightly lower (by 1.9%) than the previous month, and 2.9% lower than at the same time last year. Despite Australia's overall high storage, volumes decreased in October for 190 public storages. Some storages were relatively low in several regions including:

• central Queensland
• the northern and southern Murray–Darling Basin
• Victoria, mostly in the west
• South Australian Gulf drainage division
• western and central Tasmania
• urban areas of Perth in Western Australia.

The decrease in storage volumes were generally in regions that had below average rainfall and dry catchment conditions during October.

Combined storages in the Murray–Darling Basin were 76.3% full at the end of October, a 3.4% decrease from September and a 13.7% decrease from the same time last year. Menindee Lakes, in the west of New South Wales was 47.3% full at the end of October, a decrease of 9.2% from September and a 23.7% decrease from the same time last year. The combined storages in the Wimmera–Mallee system of Victoria were just above half full (54.4% of its capacity) at the end of October, slightly decreased (0.8%) from September and a 18.4% decrease from the same time last year, mainly due to the below average rainfall during the March to June and August to October periods. The Hume dam was at 58.6% of capacity at the end of October, a 1.6% decrease from September and a 35.1% decrease from same time last year.

Perth's surface water storages were 48.6% full at the end of October, a 0.8% increase from September, and a 2.8% decrease from the same time last year. Long-term declines in surface water inflows to Perth's storages means the city's water supply is reliant on desalination and groundwater sources.

The Harding storage in the Pilbara–Gascoyne drainage division was at 24.1% of capacity at the end of October, a 1.7% decrease from September and a 26.0% decrease from same time last year.

In central Queensland, water storage in Fairbairn was at 29.5% of capacity at the end of October, a 2.6% decrease from September and a 0.9% decrease from same time last year. Water levels in the Lake Awoonga in south-eastern Queensland remain low (39.4% full), at the end of October, a 0.8% decrease from September and a 7.1% decrease from the same time last year.

Water storage in Great Lake in central-northern Tasmania, the second largest storage by capacity in the state, was 33.4% full at the end of the month, a 0.9% increase from September but a 3.2% decrease from the same time last year