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Seasonal Climate Outlook

July 2026

Summary

For the South West Land Division (SWLD) climate models indicate below median rainfall July to September. Both daytime and night-time temperatures are expected to be warmer than normal for July to September and August to October 2026.

Recent conditions:

Rainfall in June was average to above average across the majority of the SWLD, with the exception of an area around Wagin, which recorded below-average falls.
June temperatures were average for the SWLD.
An El Niño has become established in the Pacific Ocean and is expected to persist until at least the end of the year. Most climate models indicate a positive Indian Ocean Dipole developing from September, along with an increased prevalence of high-pressure systems during winter and spring. Together, these climate drivers are likely to reduce rainfall and bring higher temperatures across the SWLD.

Rainfall summary

Rainfall since April was average across the majority of the SWLD, with the DPIRD weather station at Pemberton receiving 482 mm of rain. In contrast, the Bureau’s weather station at Ongerup has received only 43 mm. The latest soil moisture map indicates generally good level of soil moisture for the SWLD.

Figure 1. Rainfall (mm) totals for 1 April to 30 June 2026 in the SWLD. Pemberton recorded the highest total of 482 mm and the lowest total is Ongerup with 43 mm.

Figure 2. Rainfall decile map for 1 April – 30 June 2026 in the SWLD. Indicating decile 4-7 for the majority 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 June, 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 majority of the SWLD. 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 SWLD as of 30 June 2026 using FAO crop factor. Indicating high soil water for the majority of the SWLD, with low levels in Central Wheatbelt and Great Southern forecast districts.

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.

The average number of nights below 2C for July (2000-2025) indicates that Southern Cross has the highest number of nights below 2°C with 12. 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 4. Average number of nights below 2°C in July for the years 2000-2025 for the SWLD. Southern Cross has the highest number, with 11 nights below 2°C.

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 5. 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 10 models indicate below median rainfall for July 2026. This tendency towards drier than normal conditions continues to August. There is currently no clear model consensus for September and December. For October, there is model consensus for neutral chance of exceeding median rainfall and for November there is currently model consensus for above median rainfall. It is important to note that forecasts are less accurate the further ahead they look.

Figure 6. 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 July and August. Note that forecasts are less accurate the further ahead they look.

Three month

A summary of 17 national and international climate models shows that 14 models indicate below median rainfall for July to September. This tendency towards drier than normal conditions continues through to spring (September to November). There is currently no model consensus for October to December. Note that forecasts are less accurate the further ahead they look.

Figure 7. Three month model summaries of rainfall outlooks for the Central West and Central Wheatbelt forecast districts of the SWLD up to October to December 2026. Model consensus is for below median rainfall for July to September to spring (September to November). No model consensus for October to December. 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 10 models indicate below median rainfall for July 2026. This tendency towards below median rainfall continues through to October. There is currently no model consensus for November and December. Note that forecasts are less accurate the further ahead they look.

Figure 8. 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 June to October. No model consensus for November and December. Note that forecasts are less accurate the further ahead they look.

Three month

A summary of 17 national and international models shows that for July to September 2026, 15 models indicate below median rainfall. This model consensus continues through to the end of the year (October to December). Note that forecasts are less accurate the further ahead they look.

Figure 9: 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 October to December 2026. Model consensus is for below median rainfall. 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.