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Summary
The rainfall outlook for July to September 2025 shows no model consensus for the Central West and Central Wheatbelt. For the remainder of the South West Land Division (SWLD), the majority of models indicate a neutral chance of exceeding median rainfall. A neutral outlook suggests that extreme wet or dry events are less likely, and a wide range of rainfall amounts remains possible. The current outlook for spring (September to November) indicates above median rainfall for the southern part of SWLD. Temperature outlooks suggest that warmer-than-normal temperatures will persist.
Recent conditions:
· June maximum temperatures were 1-3°C above average, while minimum temperatures were about average.
· June rainfall was below average across much of the SWLD. A series of cold fronts brought rain to the west coast and along the south coast.
· The latest Department of Primary Industries and Regional Development (DPIRD) plant available soil water map shows good soil moisture levels in the south west corner and parts of the Central West and South East Coastal forecast districts. The Central Wheatbelt and Great Southern generally have low soil moisture levels.
· The Southern Annular Mode (SAM) is a climate pattern that describes the north–south movement of the strong westerly winds that circle Antarctica. It is a key climate driver in winter for the SWLD. SAM is currently positive, meaning the westerly winds have shifted closer to Antarctica, often bringing drier conditions to southern Australia. It is forecast to be positive for the next 2 weeks (until19 July) and then become neutral through to the end of July. A neutral SAM is associated with a typical winter rainfall pattern.
Rainfall summary
1 April to 29 June rainfall map shows wetter conditions in the south and drier conditions in the north and central SWLD. DPIRD’s Margaret River weather station has recorded the highest total so far this season with 533 mm. On the other end of the scale, BoM’s Williams Post Office has recorded only 18 mm since April.
Figure 1. Rainfall (mm) totals for 1 April to 29 June 2025 in the South West Land Division ̶ Margaret River has recorded the highest total of 533 mm.
Figure 2. Rainfall decile ranking map for 1 April to 29 June 2025 for the South West Land Division - indicating mixed rainfall, wetter conditions in the South East Coastal and eastern parts of the Great Southern forecast districts, average to drier elsewhere.
Plant available soil water map
Plant available soil water maps produced by DPIRD are of 2 types:
- Fallow maps, which use the Ritchie two-layer fallow evaporation model before crops emerge (produced from April to June), and
- Crop maps, produced after the crop has emerged and begun to take up water from the soil (produced from July to October).
The FAO crop factor method—also known as the FAO crop coefficient method—is a standard approach for estimating crop water use (evapotranspiration), based on the FAO-56 guidelines developed by the Food and Agriculture Organization of the United Nations.
This method assumes that, after germination, a crop progresses through 4 stages of growth. On any given day during the crop’s lifecycle, the crop coefficient for the current growth stage is multiplied by the potential evaporation to estimate plant evapotranspiration.
The crop coefficients used have been selected to suit cropping conditions in Western Australia.
The current map, which shows the plant available water averaged from 10 soil types (clay, deep loamy duplex, deep sandy duplex, gravel, loamy earth, sand, sandy earth, shallow loamy duplex and shallow sandy duplex) indicates high plant available soil water for the south west corner and parts of the Central West and South East Coastal forecast districts.
Low levels are indicated for in the Central Wheatbelt and Great Southern. For more information see DPIRD’s soil water tool.
Figure 3: Plant available soil water map for the South West Land Division as of 29 June 2025. Using FAO crop factor. Indicating high soil water for the south west corner and parts of the Central West and South East Coastal forecast districts.
Break of season
Traditionally, the ‘break of season’ was defined as the first rainfall event delivering 25 mm over 3 days after 25 April. This has since been refined to 15 mm over 3 days from 1 April, or if this threshold has not been met, 5 mm of rain over 3 days from 5 June. The DPIRD break of season map, based on BoM weather station data up to 29 June, shows that the earliest break occurred for the majority of southern locations between the on the 4 and 6 April, considerably earlier than the long term average break in mid-May. In the northern grainbelt, the break occurred in the week of 26 May to 1 June. The latest breaks were recorded at Kellerberrin, Wickepin, Cowcowling and Williams on the 21 June, around a month later than the long term average.
Figure 4. Break of season map for the South West Land Division, using the rule 15 mm of rain over 3 days after 1 April as of 29 June 2025. The earliest break was the week of 1-6 April, and the last week of 16-22 June.
Seasonal bushfire outlook
The Australian and New Zealand Council for fire and emergency services (AFAC) releases seasonal bushfire outlooks for Australia. These outlooks identify areas with an increased risk of fire but do not predict where or when bushfires will occur. It is important to note that dangerous bushfires can occur outside of the traditional fire season and in areas assessed as having a normal risk.
The AFAC seasonal bushfire outlook for winter 2025 indicates a normal risk of fire for Western Australia, while parts of South Australia and Victoria face a heightened risk. This unseasonable fire potential is driven in part, by significant and persistent dry conditions in those states. There is an abundance of dry fuel, including grass and forest vegetation, in Victoria, and in southern scrub and forest areas of South Australia. However, drought conditions have reduced fire risk and crop landscapes within these areas.
Figure 5. The Australian and New Zealand Council for fire and emergency services seasonal bushfire outlook
Rainfall outlooks
Three-month and single-month rainfall outlooks are derived from a range of national and international climate models. The outlooks are presented as the probability of rainfall being below, above, or neutral relative to the median rainfall. (Note: A neutral outlook suggests that extreme wet or dry events are less likely, and a wide range of rainfall amounts remains possible). To provide a more localised perspective, the South West Land Division has been divided into 2 regions, allowing for tailored rainfall outlooks specific to each area.
Figure 6: Rainfall outlooks are in 2 sections based on location in the South West Land Division ̶ first group includes Central West and Central Wheatbelt forecast districts, second group includes Lower West, South West, Great Southern, South Coastal and South East Coastal forecast districts.
Rainfall outlooks for the Central West and Central Wheatbelt forecast districts of the SWLD
Single month
A summary of 15 national and international models shows that 8 models indicate a neutral chance of exceeding median rainfall for July 2025. A neutral outlook also applies for August, October, November and December, with no model consensus for September. A neutral outlook suggests that extreme wet or dry events are less likely, and a wide range of rainfall amounts remains possible.
Figure 7: Single month model summaries for rainfall for the Central West and Central Wheatbelt forecast districts of the South West Land Division up to December 2025. Model consensus is for neutral for July, August, October, November and December and no model consensus for September.
Three month
A summary of 17 national and international models shows that for July to September, 4 models indicate below median rainfall, 5 suggest a neutral chance of exceeding median rainfall, and 8 indicate above median rainfall. This distribution indicates no clear model consensus for the next 3 months. Looking further ahead, there is model consensus for October to December, with a neutral outlook. A neutral outlook suggests that extreme wet or dry events are less likely, and a wide range of rainfall amounts remains possible. With no model consensus in coming months, the outlooks offer limited guidance. However, the trend in the model graph is cautiously optimistic, with fewer below median rainfall outlooks compared to neutral and above median continuing through to the end of the year.
Figure 8: Model summary of rainfall outlook for the Central West and Central Wheatbelt forecast districts of the South West Land Division up to October to December 2025. There is no model consensus until October to December.
Rainfall outlooks for the Lower west, South West, Great Southern, South Coastal and South East Coastal forecast districts of the SWLD
Single month
A summary of 15 national and international models shows that 9 models indicate a neutral chance of exceeding median rainfall for July 2025. This model consensus for a neutral outlook continues for October through to December, suggesting that extreme wet or dry conditions are less likely, with a wide range of rainfall outcomes remaining possible. There is no model consensus for August and September.
Figure 9: Single month model summaries of rainfall for the Lower West, South West, Great Southern, South Coastal and South East Coastal forecast districts of the South West Land Division up to December 2025. The majority of models are indicating neutral chances of exceeding median rainfall for July, October through to December. No model consensus for August and September.
Three month
A summary of 17 national and international models shows that 9 models indicate a neutral chance of exceeding median rainfall for July to September. A neutral outlook suggests that extreme wet or dry events are less likely, and a wide range of rainfall amounts remains possible. There is no model consensus for August to October and October to December. The current outlook for spring (September to November) indicates above average rainfall. However, it is important to note that forecast reliability decreases with longer lead times.
Figure 10: Three month model summaries for rainfall for the Lower West, South West, Great Southern, South Coastal and South East Coastal forecast districts of the South West Land Division up to October to December 2025. Neutral outlook for July to September, above average for spring September to November.
Important disclaimer
The Chief Executive Officer of the Department of Primary Industries and Regional Development and the State of Western Australia accept no liability whatsoever by reason of negligence or otherwise arising from the use or release of this information or any part of it.
Copyright © State of Western Australia (Department of Primary Industries and Regional Development), 2022
