Climate outlook for September to December

Long-range forecast overview

The long-range forecast for September to November shows:

• Rainfall is likely to be below average across parts of the south and east and above average across much of the western half of Australia
• Daytime temperatures are likely to be above average south of the tropics.
• Overnight temperatures are likely to be above average for most of Australia.

Rainfall—Summary

Below average September to November rainfall across parts of the south and east; above average in the west

September to November

• September to November rainfall is likely to be below average (60 to 80% chance) for the far south-west of Western Australia, south-eastern Australia including Tasmania, and parts of eastern and northern Queensland.
• There is an increased chance of unusually low rainfall¹ (50 to 70% chance) for parts of south-east Australia, including regions that have already experienced long term rainfall deficiencies over the past 2 years.
• Above average rainfall is likely (60% to greater than 80% chance) over most of Western Australia, the Northern Territory, western South Australia and across Queensland's Gulf Country. During this outlook period, northern Australia transitions from the dry to the wet season, bringing increased humidity, storms, and showers.
• There is an increased chance of unusually high rainfall¹ (40 to 80% chance) across much of Western Australia. Unusually high rainfall is notable for parts of the north and the south of the state which typically receive 50 mm or more during September to November while central-west and inland regions typically receive less than 50 mm during the season.

¹Unusually low/ high rainfall is that in the driest/ wettest 20% of September to November records between 1981 and 2018.

Temperature—Summary

Above average temperatures likely across much of Australia

September to November

• September to November maximum temperatures are likely to be above average (60% to greater than 80% chance) across most of Australia except in parts of the tropical north, as well as over the western Top End of the Northern Territory.
• Maximum temperatures are likely to be below average (60 to 80% chance) across areas of north-eastern Queensland and the northern Kimberley.
• There is an increased chance (over 60% chance) of unusually high maximum temperatures² across the southern two-thirds of Australia, with the highest chances (over 80%) in western parts of Western Australia and much of south-east Australia extending into southern Queensland and eastern South Australia.

• Minimum temperatures are likely (60% to greater than 80% chance) to be above average across most of Australia except in some parts of the north.
• There is an increased chance of unusually high minimum temperatures² (over 60% chance) across much of Australia except parts of the north, with the highest chances (over 80%) across most of Western Australia, South Australia, Victoria, Tasmania, New South Wales and southern Queensland.

²Unusually high maximum and minimum temperatures are those in the warmest 20% of September to November days and nights, respectively, between 1981 and 2018.

We use our long-range model, ACCESS-S, to forecast up to four months ahead. It simulates how the atmosphere and oceans may change, using millions of observations from satellites, land stations, and ocean instruments.

We also track global climate indicators to help understand long-term weather patterns. These mainly reflect how the ocean and atmosphere interact.

Current climate indicators:

• El Niño is firmly established and continues to strengthen.
• All models, including the bureau's, forecast the tropical Pacific to continue warming through the southern hemisphere spring, with El Niño likely peaking in late spring or summer as a strong to very strong event.
• A strong El Niño signal in the tropical Pacific does not necessarily mean strong impacts on Australia's climate; ENSO is only one of many factors that can influence Australia’s seasonal weather and climate.
• The Indian Ocean Dipole (IOD) is currently neutral. Models suggest a positive IOD may develop during the southern hemisphere winter and persist into spring, although there remains some variation in the likely timing and strength.
• The Southern Annular Mode (SAM) index is currently neutral as at 1 August. It is forecast to remain neutral during the coming fortnight.
• The SST analysis for the week ending 2 August 2026 shows above average waters around most of southern Australia and near average to the north. Waters are especially warm along the New South Wales and eastern Tasmanian coasts. This general SST pattern is forecast to continue over the coming months.
• Globally SSTs are exceptionally warm, with July 2026 the warmest July on record for globally averaged ocean temperatures since 1900.