Drought
Rainfall deficiencies and water availability

Below average rainfall in parts of the south and east, above average in most of Australia

November rainfall was below average to very much below average (in the lowest 10% of Novembers since 1900) for:

• southern Tasmania
• parts of southern Victoria and South Australia
• parts of south-western Western Australia
• far northern Queensland.

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

• most of Western Australia, the Northern Territory, South Australia, New South Wales, Queensland and northern Victoria
• parts of the Gascoyne, Central West districts in Western Australia and Central Wheat Belt district had highest on record November rainfall totals.
• Western Australia had its fifth-wettest November on record since 1900.

The national area-averaged mean temperature in November was 1.83 °C above the 1961–1990 average, the fifth-warmest November on record for Australia since 1910, and spring was the warmest on record at 2.08 °C above the 1961–1990 average.

Monitoring of rainfall deficiencies since August 2023 has ended. Deficiencies from February 2024 continue to be monitored. The two periods impact similar regions, except for south-west Western Australia where rainfall deficiencies since August 2023 are more widespread.

November was the second month of the northern wet season. Most of south-eastern Queensland had very much above average rainfall during November, but this rain occurred later than usual, as indicated by the northern rainfall onset threshold of 50 mm of rainfall since 1 September. Small areas of Queensland's north tropical coast have also had a later than average northern rainfall onset, while much of the north and west of Australia has had an early onset.

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. Across southern Australia (south of 26°S ) as a whole, since 1994, April to October rainfall has been above the 1961–1990 average in only 6 years. This is due to a combination of natural variability on decadal timescales and changes in large-scale circulation largely driven by an increase in greenhouse gas emissions.

The long-range forecast, released on 5 December 2024 for January to March 2025 shows:

• Rainfall is likely (60 to 70% chance) to be above average for far eastern coastal regions and for much of western and northern Australia.
• Rainfall is likely to be within the typical range for the season for most remaining areas.
• There is an increased chance of unusually high rainfall for parts of Cape York Peninsula, and western and northern Western Australia.
• Above average maximum temperatures are likely to very likely (60% to greater than 80% chance) for large parts of Australia while above average minimum temperatures are very likely across almost all of Australia.

Deficiencies for the 10 months since February 2024

For the 10-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 small areas of the eastern ranges into southern New South Wales
• coastal north-west Tasmania, King Island and the Tasman Peninsula.

Areas with lowest on record rainfall include a region around Ceduna and parts of the Eastern Eyre Peninsula, York Peninsula, Murraylands and Upper South East districts in South Australia.

Compared to October, areas of rainfall deficiency became more intense in some coastal parts of South Australia but contracted in extent in the Riverlands, and in north-western Victoria.

Significant rainfall across much of eastern Australia at the start of December may reduce rainfall deficiencies in north-eastern Victoria and southern New South Wales.

NULL

Below average soil moisture in the southern mainland and far north Queensland

November soil moisture was below to very much below average in:

• the south coasts of Western Australia and South Australia
• most of Victoria except for the Mallee district
• south-eastern New South Wales, including the Australian Capital Territory
• much of Tasmania
• parts of northern Queensland
• some inland areas around the Queensland–New South Wales border and the south of the Northern Territory.

While November rainfall totals were sufficient to ease the extent of soil moisture deficiencies in south-west Western Australia and parts of central Queensland, deficiencies intensified across southern Australia. However, in some areas where soil moisture has been very much below average, late November rainfall may reduce deficiencies in December.

High evaporative stress continues in parts of southern Australia

Evaporative stress for the 4 weeks ending 30 November 2024 was elevated (negative Evaporative Stress Index (ESI)) in:

• southern Australia including most of Tasmania
• most of Queensland excluding the south-east and north-west
• much of north-western and south-eastern New South Wales
• the south-east and north of the Northern Territory
• parts of the west coast of Western Australia.

The ESI was similar to October values over much of the country with some contraction in the area of negative values in south-west Western Australia and an intensification of moisture stress (ESI less than −2) in the south-east, particularly in western Victoria.

The ESI represents the anomaly of the ratio of actual evapotranspiration to potential evapotranspiration standardised for the time of year. A lower ratio indicates higher vegetation moisture stress due to limited water availability and can be an indicator of 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 November

• November rainfall was below average for southern Tasmania, parts of southern Victoria and South Australia, parts of south-western Western Australia, far northern Queensland and part of the central coast.
• Recent rainfall deficiency areas intensified along the southern coast of South Australia but reduced in extent in north-western Victoria.
• Soil moisture remains below average in Far North Queensland and southern Australia, with an intensification of deficiencies in the south-east.
• Streamflow was low at a large number of sites in southern Australia including Tasmania and central Queensland.
• Some water storage levels were low in the south-west of Western Australia and in central Queensland, while many storages in south-eastern states, particularly Tasmania, were 10 to 50% lower than the same time last year.

Low streamflow in southern Australia and central Queensland

In November, higher than average (based on records since 1975) streamflow was observed at 21% of the 869 sites with available data. These were mostly in the north and north-west of Australia and along the Queensland coast. Very much above average streamflow (highest 10% of years since 1975) was observed at 7% of sites, including 2% of sites with highest on record, across

• the north of the Northern Territory
• the north-west of Western Australia
• south-eastern and northern areas of Queensland
• the north-east coast of New South Wales.

This was due to above average rainfall and wet catchment conditions in those regions.

Lower than average streamflow was observed in November at 34% of sites. These were mostly associated with below average rainfall and dry catchment conditions. These were observed in:

• the South East Coast, Victoria drainage division (66 % of 101 sites)
• the South Australian Gulf drainage division (90% of 10 sites)
• central and northern areas of the North East Coast drainage division, Queensland (27% of 143 sites)
• the Murray–Darling Basin drainage division (31% of the 332 sites)
• south-west of Western Australia (61% of 78 sites)
• across Tasmania (89% of 18 sites).

Very much below average streamflow (lowest 10% of years since 1975) was observed at 8% of sites, including 1% of sites with lowest on record, mainly in western Victoria, South Australia, few sites in the south of Murray–Darling Basin, central Queensland, Tasmania and the south-west of Western Australia.

November streamflow was average at 45% of sites, spread across Australia.

Low storage levels in the west of Western Australia, southern Australia and central Queensland

By the end of November, the total water storage in Australia (across 306 public storages) was at 71.8% of capacity, slightly lower (by 2.0%) than the previous month, and 3.2% lower than at the same time last year. Despite Australia's overall high storage, volumes decreased in November for 171 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
• the South Australian Gulf drainage division
• western and central Tasmania
• urban areas of Perth and in the Pilbara–Gascoyne in Western Australia.

The decrease in storage volumes were generally in regions that had dry catchment conditions during November.

Combined storages in the Murray–Darling Basin were 73.7% full at the end of November, a 2.6% decrease from October and a 14.0% decrease from the same time last year. Menindee Lakes, in the west of New South Wales was 37.2% full at the end of November, a decrease of 10.1% from October and a 30.3% decrease from the same time last year. The combined storages in the Wimmera–Mallee system of Victoria were just above half full (51.4% of its capacity) at the end of November, a decrease of 3.0% from October and a 18.6% decrease from the same time last year, mainly due to severe rainfall deficiencies since February 2024. Water storage in Hume dam was at 55.6% of capacity at the end of November, a 3.0% decrease from October and a 32.6% decrease from the same time last year.

Perth's surface water storages were 45.5% full at the end of November, a 1.1% decrease from October, and a 1.4% 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 21.5% of capacity at the end of November, a 2.6% decrease from October and a 24.5% decrease from the same time last year.

In central Queensland, water storage in Fairbairn was at 26.1% of capacity at the end of November, a 3.4% decrease from October and a 3.8% decrease from the same time last year. Water levels in the Lake Awoonga in south-eastern Queensland remain low (38.1% full), at the end of November, a 1.3% decrease from October and a 7.5% decrease from the same time last year.

With extended rainfall deficiencies and dry catchment conditions, water storage in Great Lake in central-northern Tasmania, the second largest by capacity in the state, was 32.0% full at the end of the month. Inflow from recent rains result in a 1.4% increase from October but storage remained 1.9% below the same time last year.