Drought
Rainfall deficiencies and water availability

Above average May rainfall from the north-west to the New South Wales coast

May rainfall was below average to very much below average (in the lowest 10% of all Mays since 1900) for:

• much of the west of Western Australia
• parts of eastern Queensland
• western Tasmania and the south-east coast of South Australia.

May rainfall was above average to very much above average (in the wettest 10% of all Mays since 1900) in a band across the country covering:

• most of New South Wales, extending into north-western Victoria
• western and southern Queensland
• eastern Tasmania
• much of South Australia except for the south-east and north-west
• much of the Northern Territory and the eastern Kimberley region of Western Australia.

Further details: Monthly climate summaries, Latest National climate summary

Autumn rainfall

Rainfall was below average to very much below average (in the driest 10% of all autumns since 1900) for:

• areas in the west and interior of Western Australia
• parts of north-eastern New South Wales and southern Queensland
• most of Tasmania
• pockets of Victoria south of the Dividing Range, extending into south-eastern South Australia.

Autumn rainfall was above average to very much above average (in the wettest 10% of all autumns since 1900) for:

• the Northern Territory and South Australia
• most of Victoria north of the Dividing Range
• western New South Wales extending into the Riverina
• western, northern and parts of central Queensland
• parts of the Kimberley region in Western Australia, and around the Dampier Peninsula and the south-east of the state.

Autumn rainfall was highest on record for parts of:

• the Daly River catchment in the Top End of the Northern Territory
• Lake Eyre Basin (the catchment for Kati Thanda-Lake Eyre) in South Australia.

South Australia and the Northern Territory overall had their fourth- and seventh-wettest autumns on record, respectively.

Multi-year rainfall deficiencies

Rainfall for the 36 months ending in May 2026 has been below average (in the lowest 30% of all such periods since 1900) for:

• large areas of the west and south-west of Western Australia
• the agricultural areas in South Australia
• much of Victoria and Tasmania
• areas along New South Wales western slopes, and into southern Queensland.

Areas of lowest on record rainfall (for all respective 36-month periods since 1900) have persisted in south-west Western Australia, and have continued to expand in south-eastern South Australia and south-western Victoria.

Maps: Recent and historical rainfall maps

State of the Climate 2024 reported that there has been a shift towards drier conditions across southern Australia, especially for the cool season months from April to October. Even with occasional wetter seasons in some areas, southern Australia has recorded below-average April–October rainfall in 26 of the 32 years from 1994 to 2025.

The decline in southern Australia's cool season rainfall is linked to rising surface pressure and shifts in large-scale weather patterns, with more high-pressure systems and fewer rain-producing lows and cold fronts.

Long-range forecast for June to August

The long-range forecast, released on 4 June 2026 for June to August 2026 shows:

• Rainfall is likely to be below average for much of southern, central and eastern Australia,
• Daytime temperatures are likely to be above average for most of Australia except in parts of the north.
• Overnight temperatures are likely to be above average for much of Australia.

Deficiencies for the 5 months since January 2026

For the 5 months ending in May 2026, areas with severe or serious rainfall deficiencies (rainfall totals in the lowest 5% or 10% of years, respectively, since 1900) include:

• parts of north-eastern New South Wales into southern Queensland
• small areas along west facing coasts in Victoria
• areas in western and northern Tasmania
• a large area of the Pilbara–Gascoyne drainage division in Western Australia and small areas in the south-west.

Since April 2026, rainfall deficiency areas have contracted significantly and reduced in intensity in north-eastern New South Wales, southern Queensland and eastern Tasmania. A large area of lowest on record January to April rainfall in New South Wales has eased to 'serious or severe deficiency' (in the lowest 5% or 10% of years, since 1900) for the January to May period. Deficiencies increased during May in Western Australia, where a large deficiency area developed in the Pilbara–Gascoyne region.

Deficiencies for the 24 months since June 2024

For the latest 24-month period ending in May 2026, areas with severe or serious rainfall deficiencies (rainfall totals in the lowest 5% or 10% of periods, respectively, since 1900) extend across:

• parts of south-eastern agricultural regions in South Australia
• parts of southern and eastern-central Victoria
• parts of southern New South Wales
• small areas in Tasmania and south-west Western Australia

Compared with the 24-month period ending in April 2026, rainfall deficiencies have contracted slightly in South Australia and eased in intensity in parts of south-western Victoria. Deficiency areas expanded further north in southern New South Wales.

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Soil moisture was below average in areas of the west, the far south and parts of the east

During May, areas with root-zone soil moisture deficits developed in large areas of the west, and in parts of the south-east, including Tasmania, but deficit areas contracted significantly in north-eastern New South Wales and southern Queensland.

May root-zone soil moisture (0–1 m) was below to very much below average (in the lowest 10% of all Mays since 1911) for:

• areas in the south, west and inland Western Australia
• an inland area in the west of South Australia
• parts of south-eastern coastal fringes
• much of Tasmania
• areas in eastern New South Wales
• parts of southern, northern and eastern Queensland.

Above average soil moisture continued through most central areas of Australia, from the north to the south, and extended into eastern states.

Evaporative stress decreased in much of the east, but increased the west

Evaporative stress for the 4 weeks ending 31 May 2026 was elevated (negative Evaporative Stress Index (ESI)) in:

• the western slopes in northern New South Wales
• parts of southern and eastern Queensland
• most of Western Australia except the far north and parts of the south coast
• south-western Tasmania.

Despite above average rainfall in May, evaporative stress (where negative ESI values mean the landscape is drying out faster than normal), was still high in southern Queensland and northern New South Wales. Evaporative stress was high in most of Western Australia following below average rainfall, and in central-eastern Queensland and southern Tasmania which had areas of low rainfall and elevated temperatures. Most of Tasmania had its highest May daytime temperatures on record.

Negative ESI values can indicate vegetation moisture stress reflecting agricultural and ecological drought. A rapid decrease in ESI values can be an indicator of flash drought. Further details: Calculation and use of the ESI in drought monitoring.

Rainfall deficiencies and water availability at the end of May

• May rainfall was above average in a large band extending from the north-west across central Australia to New South Wales and southern Queensland, and below average for much of the west coast of Western Australia, northern coastal Queensland and some western-facing coastal areas in the south-east.

• Areas with year-to-date rainfall deficiencies for 2026 contracted in the east, but deficiencies developed in the Pilbara–Gascoyne region in Western Australia.
• Areas with rainfall deficiencies for the latest 24 months include coastal regions in the south-eastern states, and parts of southern New South Wales.
• Soil moisture deficits have eased in north-eastern New South Wales and in south-eastern Queensland, but have increased in parts of Western Australia and parts of eastern Queensland.
• Streamflow was lower than average at many sites across southern Australia, northern New South Wales and southern Queensland.
• Some water storages in the eastern and southern states are low at or below 50% of their capacity.

Low streamflow in southern Australia, northern New South Wales and southern Queensland

Streamflow was below average at 24% of the 906 sites with available data across Australia in May (based on records since 1975). Below to very much below average rainfall, particularly in the west of Western Australia, reduced root-zone soil moisture and runoff in those catchments. Regions with lower-than-average streamflow included:

• western areas of the South East Coast (Victoria) drainage division (23% of 98 sites) and sites in the South Australian Gulf (50% of 10 sites)
• Tasmania (43% of 21 sites)
• across the Murray–Darling Basin (32% of 339 sites) and central and northern areas of the South East Coast (New South Wales) drainage division (9% of 108 sites)
• across the North East Coast (11% of 166 sites) and two sites in the Lake Eyre Basin
• across the South West Coast drainage division of Western Australia (53% of 76 sites) and sites in the Pilbara–Gascoyne drainage division (40% of 15 sites).

Lower-than-average root zone soil moisture and decreased runoff in parts of north-eastern New South Wales, southern Queensland and southern Australia contributed to the very much below average May streamflow in catchments there. Very much below average streamflow (in the lowest 10% of years since 1975) was recorded in May at 5% of sites, including:

• in the north-east and south areas of the Murray–Darling Basin (6% of 339 sites)
• western areas of the South East Coast (Victoria) (8% of 98 sites), and a single site in Tasmania (5% of 21 sites)
• a single site in the South Australian Gulf and a single site in the Lake Eyre Basin
• a single site in the south of the North East Coast drainage division (1% of 166 sites)
• sites in the South West Coast drainage division of Western Australia (17% of 76 sites) and a single site in the Pilbara–Gascoyne drainage division.

Streamflow in May was average at 53% of sites spread across the country.

Above average streamflow was recorded at 23% of sites, with 5% of sites observing very much above average streamflow (in the highest 10% of years since 1975). Regions with above average streamflow included:

• the Tanami–Timor Sea Coast drainage division (97% of 29 sites), across the Carpentaria Coast drainage division (78% of 32 sites) and in the Lake Eyre Basin drainage divisions in Queensland (44% of 9 sites)
• across the North East Coast drainage division in Queensland (33% of 166 sites)
• sites in the South East Coast (New South Wales) drainage division (27% of 108 sites) in addition to eastern and southern areas of the Murray–Darling Basin (16% of 339 sites)
• four sites in central areas of the South East Coast (Victoria) drainage division (4% of 98 sites) and a single site in the South Australian Gulf
• three sites in Tasmania
• the South West Coast drainage division of Western Australia (6% of 76 sites)

In May, higher than average root zone soil moisture and increased runoff in parts of northern Australia, contributed to the above average May streamflow in those catchments.

Low water storage levels in western Victoria, the southern Murray–Darling Basin and central Queensland

By the end of May, total water storage across Australia—based on 302 public storages—was at 65.2% of capacity, down by 2.0% from the previous month, and is similar to this time last year. Storage volumes decreased in 156 storages during May, with 92 storages below 50% at the end of the month being in:

• central eastern Queensland
• the southern and eastern Murray–Darling Basin
• Victoria
• south eastern South Australia
• Perth urban storages
• central Tasmania.

Declines in storages across eastern New South Wales and south-eastern Queensland were largely driven by a reduced catchment runoff associated with below to very much below average rainfall across these areas. In Victoria, predominantly below-average rainfall conditions during May, together with persistently dry catchment conditions since 2023, have reduced inflows to major storages. Storage levels remain low Western Australia with extended dry conditions over several years limiting inflows.

North East Coast

Overall, water storages in the North East Coast drainage division were at 79.6% of capacity at the end of May. Some storages were at full capacity, but many had decreased from last month, and several storages remained below 50%. Fairbairn Dam, Queensland’s second-largest storage, finished the month at 33.5%, down 1.5% compared to the previous month, and an increase of 10.6% from last year.

South-eastern Australia

Many storages across the Murray–Darling Basin and the South East Coast (Victoria) drainage divisions were below or close to 50% of capacity at the end of May, including Hume Dam, Australia’s seventh-largest reservoir, and Lake Eucumbene. Hume Dam decreased by 2.6% during May, finishing at 24.2%, and 3.6% lower than at the same time last year. Menindee Lakes in western New South Wales decreased slightly by 0.4%, finishing at 25.3% of capacity at the end of May and 35.6% lower than this time last year.

The overall storage volume across the Murray–Darling Basin increased by 1.2% during May, finishing the month at 48.9%, and 9.1% lower than at this time last year. In the southern Murray–Darling Basin increased by 1.6% over the month, finishing at 47.3% capacity at the end of May, around 10.0% lower than at the same time last year. Increases over the past month are the result of above average rainfall leading to higher inflows. We are entering the early filling season, and current indicators suggest a mixed but cautiously positive start with rain in May helping to lift soil moisture and prime catchments for inflows if further rain arrives.

While parts of Victoria recorded moderate rainfall during May, western catchments received relatively low totals, generally around 25 to 50 mm. Ongoing rainfall deficiencies across these areas have resulted in average to below average soil moisture and limited runoff. Overall storage volume across the South East Coast (Victoria) drainage division decreased by 2.5% in May, ending the month at 36.8%. In the Wimmera–Mallee system, a critical rural water supply for domestic and agricultural use in western Victoria, storages were at 31.7% of capacity, slightly up by 0.4% compared to the previous month, and 3.6% lower than at the same time last year.

Urban storages

At the end of May, surface water storages supplying most capital cities were close to or above 80% of accessible capacity, except for Melbourne, Adelaide and Perth. Storages for these cities are relatively low, following extended periods of severe rainfall deficiencies reducing storage inflows and increasing water demand.

Perth's surface water storages were at 35.7% of accessible capacity at the end of May, a slight decrease of 0.8% from the previous month, and slightly lower (0.5%) than at the same time last year. The long-term decline in surface water inflows has reduced the contribution of surface storages to Perth’s water supply, and the city continues to rely heavily on desalination and groundwater to meet its water demand.

Adelaide's storages were 42.8% full at the end of May, a decrease of 1.6% from the previous month, but were 8.4% higher than at this time last year. By the end of May, five of Adelaide’s metropolitan storages were at or below 50% capacity. Storage levels have been influenced by prolonged dry conditions, historically low catchment inflows, limited rainfall during key inflow periods, and high-water demand over the summer period. Adelaide’s urban water supply is supplemented by transfers from the River Murray, with additional climate-independent supply provided by desalination and groundwater.

Rainfall was average to below average across much of Victoria during May, and Melbourne's water storages decreased by 1.9% from the previous month, finishing at 63.5% capacity. Melbourne's storages have declined by 9.5% since this time last year, reflecting ongoing rainfall deficiencies, very low catchment inflows, and increased water demand. In response to persistent rainfall deficiencies, the Victorian desalination plant has been in operation to support water supply to the Melbourne and Geelong areas.