Weekly Australian Climate, Water and Agricultural Update, 9 January 2025

In the week ending 8 January 2025, low-pressure systems and a series of troughs brought rainfall to much of the country, excluding central inland regions.

• Isolated areas of the Northern Territory and northern and coastal Queensland recorded falls of up to 150 millimetres; far-north Queensland recorded higher rainfall. 
• Much of Western Australia and New South Wales, received between 5– 100 millimetres; Victoria and southern Queensland received between 5–50 millimetres.
• South Australia and Tasmania recorded lower rainfall totals, up to 15 millimetres in isolated areas. 

Rainfall totals were mixed across cropping regions:

• Southern cropping regions received little to no rainfall. This included much of Western Australia and southern New South Wales (0–25 millimetres), Victoria (5–25 millimetres), and South Australia (little to no rainfall). 
• In the east, rainfall totals were generally higher, with Queensland and northern New South Wales recording between 5–50 millimetres. For areas that recorded significant rainfall this week, this will likely provide a boost to soil moisture levels, benefitting summer crop production. 

Rainfall for the week ending 8 January 2025

Over the 8 days to 16 January 2025, low-pressure systems are expected to bring relatively high rainfall totals to northern and eastern parts of Australia.

• Falls of between 15–100 millimetres are likely for much of northern Western Australia, the Northern Territory, and northern Queensland. Higher rainfall totals are expected in isolated areas, with up to 150 millimetres forecast in scattered areas of eastern New South Wales and northern Western Australia. Between 15–100 millimetres of rainfall are forecast for much of eastern Queensland and eastern New South Wales.
• By contrast, lower rainfall totals are expected across the southeast including across eastern Victoria (15–50 millimetres) and Tasmania (50 millimetres). High-pressure systems are expected to keep the central and southwest largely dry.

Rainfall forecasts over the coming week are mixed across cropping regions:

• Low rainfall totals are expected in the south including across much of south Western Australia and South Australia (5 – 10 millimetres each) and Victoria (5–25 millimetres).
• Higher rainfall is expected in the east, with much of Queensland and eastern New South Wales likely to receive between 15–100 millimetres. Rainfall forecast for summer cropping regions in Queensland and New South Wales will likely provide a boost for soil moisture levels and support the germination and growth of crops already in the ground.

Total forecast rainfall for the period 9 January to 16 January 2025

Most of Australia received average to extremely good rainfall totals over December 2024, relative to historical December averages.

• Rainfall was well above average to extremely high across much of the west of the country, as well as the northern tropics, southeast Queensland, central New South Wales, and much of Tasmania.
• Above average to well above average rainfall was recorded in regions of central Australia, including the southern Northern Territory and northern South Australia.
• In contrast, southwest Western Australia, southern South Australia, southern Victoria, and eastern regions of New South Wales saw below average to extremely low rainfall.

The remainder of Australia saw generally average November rainfall.

• In cropping regions, December rainfall was mixed, with generally below average rainfall in the south and west, and average to above average in the east:
• Much of South Australia and southwest Western Australia observed well below average to extremely low rainfall, however, northern margins of Western Australia’s cropping regions saw above average to extremely high rainfall.
• Central New South Wales and scattered areas of Queensland and Victoria recorded above average rainfall. Above average rainfall totals in Queensland and northern New South Wales are likely to support the build-up of soil moisture and benefit the sowing and establishment of summer crops.

Rainfall percentiles for December 2024

In December 2024, modelled upper layer soil moisture was generally average to above average across much of the country.

• Much of Western Australia, the southern Northern Territory, and northern and coastal Queensland saw very much above average soil moisture for the period.
• Very few parts of Australia recorded below average soil moisture, limited to isolated areas in southwest Western Australia, coastal New South Wales, and eastern regions of Victoria and South Australia.

At this time of year, upper layer soil moisture is important at the beginning of the summer cropping season and for pasture growth across northern Australia since plant germination and establishment utilise this moisture. It is also an important indicator of the ability to access paddocks for summer crop planting activities.

Across cropping regions, modelled upper layer soil moisture in December was generally above average across much of the east including central New South Wales and Queensland, as well as northern areas of Western Australia:

• In Western Australia, upper layer soil moisture varied considerably between northern (very much above average) and southern (very much below average) cropping regions.
• In South Australia, upper layer soil moisture was low in the east. Victorian soil moisture was broadly average over the period.

While average to above average upper layer soil moisture in New South Wales and Queensland would have supported the growth and establishment of summer crops already in the ground, it is likely to have interrupted harvest completion and access for ongoing summer crop planting.

Modelled upper layer soil moisture for December 2024

Across much of Australia, modelled lower layer soil moisture in December 2024 was average to very much above average.

• Much of Western Australia, the Northern Territory, Queensland, Tasmania, central New South Wales, and much of northern Victoria and South Australia saw very high soil moisture levels.
• By contrast, parts of the far south, including southern Western Australia, South Australia, Victoria, and east cost of New South Wales were modelled as having very much below average soil moisture.

At this time of year increased levels of lower layer soil moisture will be important to support summer crops and pasture growth during a peak growth period.

Across cropping regions, modelled lower layer soil moisture was generally above average in the east with areas of extremely low conditions modelled in the west:

• Much of southern and central Queensland, New South Wales, and northern Victoria modelled very much above average soil moisture, as well as the northern margins of Western Australia.
• In contrast, parts of southern South Australia and southern Western Australia saw below average soil moisture for this time of year.

Average to above average lower layer soil moisture is likely to provide a reserve of plant-available water for summer crops later in the growing season. Agricultural regions across southern Australia with extremely low levels of stored soil moisture will require sufficient and timely rainfall over summer to arrest declining levels of pasture availability.

Modelled lower layer soil moisture for December 2024

Pasture growth for the three months to December 2024 has been mixed across much of Australia, with northern parts of the country experiencing stronger pasture growth:

• Average to extremely high pasture growth was modelled across much of northern and central Australia, including the Northern Territory, eastern Queensland, northern Western Australia and northern South Australia. 
• Average to above average pasture growth was observed in south-eastern Queensland, northern South Australia, and central Tasmania. 

Pasture growth is expected to support farmers maintaining stock numbers, provide opportunities to build standing dry matter availability and replenish fodder supplies during late spring and early summer. By contrast, large areas of eastern and southern Australia saw relatively low pasture growth for this time of year:

• Extremely low to below average pasture growth was modelled across much of central and south-eastern New South Wales, Victoria, southern South Australia and part of southern Western Australia. 
• Expected lower pasture availability will likely see graziers in affected regions more reliant on supplemental feed to maintain current stocking rates and production.

Relative pasture growth for 3-months ending December 2024 (1 October to 31 December 2024)

The El Niño Southern Oscillation (ENSO), Southern Annular Mode (SAM), and Indian Ocean Dipole (IOD) climate drivers are currently neutral and having minimal influence on Australian rainfall. The IOD and SAM are likely to remain neutral over the coming weeks, however, indicators suggest that chances of a La Nina event are strengthening. 

The most recent rainfall outlook for February 2025 provided by the Bureau of Meteorology indicates that much of eastern Australia, including eastern Queensland and New South Wales, as well as parts of Western Australia are likely to see above median rainfall. For the remaining regions, rainfall is expected to be average.

• The Bureau of Meteorology’s climate model predicts a 75% chance of February rainfall totals between 50–200 millimetres across much of the north, including northern Western Australia and the Northern Territory. Parts of northern Queensland are expected to see as much as 400 millimetres. 
• Lower rainfall totals are expected across eastern areas, with much of southern Queensland, New South Wales, Victoria and Tasmania likely to see between 5–100 millimetres. In South Australia and southern Western Australia, little to no rainfall is expected. 

Across cropping regions, there is a 75% chance of:

• Relatively strong rainfall across much of New South Wales (between 10–25 millimetres) and Queensland (between 25–100 millimetres). If realised, this rainfall is likely to support above average yield prospects for summer crops and average or better levels of pasture production in affected areas.
• Little to no rainfall is expected across remaining southern cropping regions. This forecast is typical for this time of year, expected to lead to continued low levels of pasture growth and increased livestock turn-off.

Rainfall totals that have a 75% chance of occurring in February 2025

The rainfall outlook for February to April 2025 indicates an increased probability of above average rainfall across large areas of eastern, northern and western Australia. Much of the south of the country is equally likely to receive above or below median rainfall, except western Tasmania, which is unlikely to see median rainfall over the period.

Across cropping regions, the chance of receiving above median rainfall is between 55–75% across much of Queensland, with New South Wales, Victoria, and Western Australia having a 55–65% chance of above median rainfall. In South Australia, the chances of receiving above or below median rainfall are approximately equal.

Rainfall totals that have a 75% chance of occurring January 2025 to March 2025

The outlook for February through to April suggests a 75% chance of receiving rainfall totals of between 200–600 millimetres across northern Western Australia, the Northern Territory, and Queensland, with rainfall greater than 600 millimetres expected in far-north Queensland and the Northern Territory. Between 50–200 millimetres of rainfall is forecast across much of southern Queensland, New South Wales, Victoria and Tasmania, with rainfall totals exceeding 200 millimetres likely across coastal and alpine areas. The far southwest of Western Australia is likely to receive rainfall totals of between 50–100 millimetres over this period, while South Australia is likely to receive between 25–50 millimetres.

In summer cropping regions, there is a 75% chance of receiving between 100–200 millimetres of rainfall across much of Queensland and northern New South Wales. If realised, these forecast rainfall totals are likely to be sufficient to support summer pasture growth across eastern and northern Australia. Additionally, these expected falls are likely to provide a boost to soil moisture profiles and maintain above yield expectation for summer crops in Queensland and northern New South Wales. In the south, rainfall totals are likely to be lower, with between 25–100 millimetres forecast for much of Western Australia and Victoria, and between 10–50 millimetres in South Australia.

Rainfall totals that have a 75% chance of occurring February 2025 to April 2025