Long-range forecast overview

The long-range forecast for October to December shows:

• Above average rainfall is likely across much of eastern Australia.
• Daytime temperatures are likely to be above average for most of Australia except in parts of the eastern New South Wales.
• Overnight temperatures are very likely to be above average across most of Australia.

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Rainfall—Summary

Above average rainfall likely for much of eastern Australia

October to December

• Rainfall is likely to be above average (60% to 80% chance) for most of the eastern half of Australia and north-west parts of Western Australia.
• For parts of western Tasmania, rainfall is likely to be below average (60 to 70% chance).
• Elsewhere, the forecast signal is weak, meaning roughly equal chances above or below average rainfall.
• During October and November, northern Australia gradually builds towards the wet season, bringing increased humidity, storms, and showers.

Temperature—Summary

Warmer than average days and nights likely across most of Australia

October to December

• Maximum temperatures are likely to be above average (60% to over 80% chance) across most of Australia.
• For parts of coastal New South Wales, and south-eastern Queensland, maximum temperatures have an equal likelihood of being above or below the average, indicating a weak forecast signal.
• There is an increased chance of unusually high maximum temperatures¹ (over 50% chance) in parts of northern and south-east Australia, with the strongest chances over Tasmania (60% to 80% chance).
• Minimum temperatures are likely to be above average (60% to over 80% chance) across Australia.
• There is an increased chance of unusually high minimum temperatures¹ (over 50% chance) across most of the country, with the strongest chances across northern, central and eastern Australia (60% to over 80% chance).

¹Unusually high maximum and minimum temperatures are those in the warmest 20% of October to Decemberdays 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:

• Since July 2024, sea surface temperatures (SSTs) in the Australian region have been the warmest or second warmest on record for each respective month. Similarly, global SSTs remain substantially above average, with August 2025 the third warmest on record.
• SSTs for the week ending 14 September 2025 were warmer than average across much of the Australian region, particularly along the east coast. Near-average to slightly cooler-than-average waters are present off northern Australia and in the Great Australian Bight.
• Forecasts for October to December show warmer-than-average SSTs are likely to the north, east, and south-east of Australia, with near-average temperatures around southern Western Australia and South Australia. Warmer oceans can provide increased moisture and energy, that can enhance the severity of storms and rain systems.
• The El Niño–Southern Oscillation (ENSO) is neutral. The Bureau's model suggests La Niña levels may be reached briefly during spring before returning to neutral in summer. Similarly, international models indicate some further cooling is likely, also reaching La Niña levels during spring, with all but one returning to neutral by the end of summer.
• The Indian Ocean Dipole (IOD) index has now met the negative IOD threshold for 8 consecutive weeks, sufficient to be classified as a negative IOD event. The Bureau's model predicts the negative IOD event to continue throughout spring, with a return to neutral in early summer.