September 2026
Summary
For the Central West and Central Wheatbelt forecast districts of the South West Land Division (SWLD), there is no model consensus for spring (September to November 2026) rainfall. For the remainder of the SWLD, the rainfall outlook is for below median rainfall. Both daytime and nighttime temperatures are expected to be warmer than normal during spring (September to November 2026) and through to the end of the year (October and December 2026).
Recent conditions
Rainfall in August was average to above average after a series of cold fronts in late August.
August maximum temperatures were above average for the SWLD. Minimum temperatures were average to below average, with Wickepin North having 18 nights below 2°C, which was 9 more than the average for August.
The El Niño in the Pacific Ocean is forecast to persist until autumn 2027. An El Niño over spring/summer can increase bushfire risk, delay the onset of the wet season in northern Australia and reduce the number of tropical cyclones.
The Seasonal Bushfire Outlook for spring 2026, released by AFAC (the Australian and New Zealand Council for fire and emergency services), has identified a heightened risk of fire across northern and south-eastern New South Wales, south-east Queensland, north-eastern Tasmania, parts of Western Australia, South Australia and Victoria, and large parts of the Northern Territory.
Outlook summary
Rainfall summary
Rainfall since April has been variable across the SWLD. The DPIRD weather station at Pemberton has recorded 719 mm of rain. In contrast, the Bureau’s weather station at Borden has received only 68 mm. The rainfall decile map, which compares this year’s rainfall with the 1975–2025 period, shows the variation in rainfall across the SWLD.
Figure 1. Rainfall (mm) totals for 1 April to 31 August 2026 in the SWLD. Pemberton recorded the highest total of 719 mm and the lowest total is Borden with 68 mm.
Figure 2. Rainfall decile map for 1 April to 31 August 2026 in the SWLD. Indicating decile 1-3 for half of the SWLD.
Plant available soil water map
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, using data up to 30 August, 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 good plant available soil water in the south-west corner of the SWLD. Low levels are indicated in the Central West and Great Southern. For more information see DPIRD’s soil water tool.
Figure 3. Plant available soil water map for the SWLD as of 30 August 2026 using FAO crop factor. Indicating high soil water for some parts of the SWLD.
Number of nights below 2°C
The number of nights below 2°C provides an indication of frost risk. These maps are generated using data from 332 Bureau of Meteorology and 175 DPIRD stations. Both sets of weather stations measure air temperature in a shaded enclosure (usually a Stevenson Screen) at a height of approximately 1.2 m above the ground. A temperature of 2°C at 1.2 m is equivalent to 0°C at ground level, which is cold enough to cause significant damage to cereal crops.
In August DPIRD weather station Wickepin North had the highest number of nights below 2°C, with 18, which is 9 nights more than the 2000-25 average. Burracoppin had fewer nights than the average, with 2, which is 5 nights less than the average.
Figure 4. Difference in the number of nights below 2°C in August 2026 from the 2000-25 average for the SWLD. Wickepin North had 9 nights more, while Burracoppin had 5 nights less than the average.
The average number of nights below 2°C in September (2000-25) indicates that York, Wandering and Newdegate have the highest number, with an average of 8 nights below 2°C. Despite the outlook for warmer than normal minimum temperatures, frost remains a risk in frost-prone areas. Reduced cloud cover associated with high-pressure systems can increase overnight heat loss, leading to colder surface temperatures and favourable conditions for frost formation.
Figure 5. Average number of nights below 2°C in August for the SWLD (2000-25). York, Wandering and Newdegate have the highest number, with 8 nights below 2°C.
Seasonal Bushfire Outlook spring 2026
The Seasonal Bushfire Outlook for spring 2026, released by AFAC (the Australian and New Zealand Council for fire and emergency services), identifies a heightened risk of bushfire for parts of the Gascoyne, Mid West and South Coastal forecast district of WA.
Figure 6. The Seasonal Bushfire Outlook for spring 2026, released by AFAC, identifies a heightened risk of fire across northern and south-eastern New South Wales, south-east Queensland, north-eastern Tasmania, parts of Western Australia, South Australia and Victoria, and large parts of the Northern Territory.
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 SWLD has been divided into 2 regions, allowing for tailored rainfall outlooks specific to each area.
Figure 7. Rainfall outlooks are in 2 sections based on location in the SWLD ̶ 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 14 national and international climate models shows that 12 models indicate below median rainfall for September 2026. For October through to December, there is model consensus for above median rainfall. It is important to note that forecasts are less accurate the further ahead they look.
Figure 8. Single-month model summaries of rainfall outlooks for the Central West and Central Wheatbelt forecast districts of the SWLD up to December 2026. Model consensus is for below median rainfall for September and above median rainfall for October through to December. Note that forecasts are less accurate the further ahead they look.
Three-month
A summary of 17 national and international climate models indicates that there is no model consensus for spring (September to November) 2026 rainfall. For October to December 2026 and November 2026 to January 2027 there is model consensus for above median rainfall. For December 2026 to February 2027 there is no model consensus. Note that forecasts are less accurate the further ahead they look.
Figure 9. Three-month model summaries of rainfall outlooks for the Central West and Central Wheatbelt forecast districts of the SWLD up to December 2026 to February 2027. There is no model consensus for spring (September to November). Note that forecasts are less accurate the further ahead they look.
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 14 national and international climate models shows that 13 models indicate below median rainfall for September 2026. For October, there is model consensus for neutral chance of exceeding median rainfall. A neutral chance suggests that extreme wet or dry events are less likely, and a wide range of rainfall amounts remains possible. For November and December there is model consensus for above median rainfall. Note that forecasts are less accurate the further ahead they look.
Figure 10. Single-month model summaries of rainfall for the Lower West, South West, Great Southern, South Coastal and South East Coastal forecast districts of the SWLD up to December 2026. Model consensus is for below median rainfall for September. Note that forecasts are less accurate the further ahead they look.
Three-month
A summary of 17 national and international models shows that for spring, September to November 2026, 11 models indicate below median rainfall. For November 2026 to January 2027, model consensus is for above median rainfall. For October to December 2026 and December 2026 to February 2027, there is no model consensus. Note that forecasts are less accurate the further ahead they look.
Figure 11. Three-month model summaries of rainfall outlooks for the Lower West, South West, Great Southern, South Coastal and South East Coastal forecast districts of the SWLD up to December 2026 to February 2027. Model consensus is for below median rainfall for spring, September to November 2026. Note that forecasts are less accurate the further ahead they look.
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), 2026
