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Seasonal Climate Outlook

April 2026

Summary

Models indicate a below median rainfall for the South West Land Division (SWLD) for April to June through to July to September 2026. Both daytime and night-time temperatures are expected to be warmer than normal for April to June and May to July 2026.

Recent conditions:

March rainfall: rainfall was above average for the majority of the SWLD due to mid-level trough interaction with Tropical Cyclone Narelle in late March. However, rainfall was patchy, with a few locations receiving less than 10 mm (Geraldton airport, Mingenew NW, Mount Walker).
March temperatures: In the SWLD maximum and minimum temperatures were average.
Tropical Cyclone Narelle: Tropical Cyclone (TC) Narelle formed on 17 March in the Coral Sea. Severe TC Narelle made first landfall in the far north Queensland coast on 20 March as a category 2 system, crossed into the Gulf of Carpentaria and then made a second landfall in the Northern Territory. It reached north-east Kimberley on 23 March and then landfall south of Coral Bay on 27 March. Severe TC Narelle was the tenth TC in the Australian region this season (2025–26), the sixth TC that has reached severe tropical cyclone intensity, and the sixth to make landfall. It is only the second system, after Severe TC Ingrid in March 2005, to have made landfall three times at Severe intensity, since reliable records of intensity began in 1980-81, and only the third to have made landfall in each of Queensland, the Northern Territory and Western Australia. For more information on the Australian tropical cyclone season check the Bureau of Meteorology webpage.

Rainfall summary

Rainfall in March was above average for the majority of the SWLD, thanks to the mid-level trough interaction with Tropical Cyclone Narelle in late March. Highest total was Pinjarra with 123 mm and the lowest total was Geraldton Airport with 6 mm. Rainfall from November 2025 to 31 March 2026 was decile 4-7 for the majority of the SWLD, from rainfall in November and Tropical Cyclones Mitchell and Narelle in February and March. The highest total since November was 256 mm at Quick Dam (north Denmark) while the lowest was 32 mm at Hill River (Jurien).

Figure 1: Rainfall (mm) totals for 1 to 31 March 2026 in the SWLD. Pinjarra recorded the highest total of 123 mm and Geraldton airport the lowest with 6 mm.

Figure 2: Rainfall decile map for 1 - 31 March 2026 in the SWLD. Map indicates decile 8-9 for the majority of the SWLD.

Figure 3: Rainfall (mm) totals for 1 November to 31 March 2026 in the SWLD. Quickup Dam (north Denmark) recorded the highest total of 256 mm, the lowest was Hill River (Jurien) 32 mm.

Figure 4: Rainfall decile map for 1 November 2025 to 31 March 2026 in the SWLD. Indicating decile 4-7 for the majority of the SWLD.

Soil water map from Australian Water Outlook

The current root zone soil moisture ranking from the Bureau of Meteorology’s Australian Water Outlook is above average to very much above average across the SWLD. Root zone soil moisture is the sum of water in the Australian Landscape Water Balance model’s upper and lower soil layers, representing the percentage of available water content in the top 1 m of the soil profile.

Figure 5: Relative root zone soil moisture ranking for 30 March 2026 from the Bureau of Meteorology’s Australian Water Outlook. Indicating soil moisture is above average to very much above average in the South West Land Division.

Deep-layer soil moisture represents the percentage of available water content between 1-6 m in the soil profile. The maximum storage within this layer is determined by soil depth and the relative soil water storage capacity. The deep-layer soil moisture ranking indicates below average across most of the SWLD, with levels in the lowest 1% for South East Coastal forecast district. In contrast, soil moisture is above average in the Central West forecast district due to rainfall from Tropical Cyclones Mitchell and Narelle.

Figure 6: Relative deep layer soil moisture ranking for 30 March 2026 from the Bureau of Meteorology’s Australian Water Outlook. Indicating soil moisture at depth is above average in the Central West forecast district and below average for the majority of the South West Land Division.

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 models shows that 7 models indicate below median rainfall for April 2026. This below median rainfall model consensus applies for July and August 2026. There is neutral model consensus for May and June. 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 September, with only 4 models available this far out, with 2 indicating below median rainfall and 2 neutral chances of exceeding 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 August 2026. Model consensus is for neutral chances of exceeding median rainfall for March, May and June. Model consensus is for below median rainfall for April, July and August. Note that forecasts are less accurate the further ahead they look.

Three month

A summary of 17 national and international models shows that for April to June 2026, 10 models indicate below median rainfall. This below median outlook continues through to July to September. 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 July to September 2026. Model consensus is for below median rainfall. 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 models shows that 8 models indicate below median rainfall for April 2026. This below median rainfall model consensus is also for July through to September. For May and June, there is model consensus for neutral chances 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. 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 September 2026. Model consensus is for a below median rainfall for April, July, August and September. For May and June there is model consensus for neutral chances of exceeding median rainfall. Note that forecasts are less accurate the further ahead they look.

Three month

A summary of 17 national and international models shows that for April to June 2026, 9 models indicate below median rainfall. This below median outlook continues through to July to September. 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 July to September 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.