Climate outlook for December to March

Long-range forecast overview

The long-range forecast for December to February shows:

• Rainfall is likely to be below average for large areas of Australia and above average in parts of eastern and far northern Queensland.
• Daytime temperatures are likely to be above average across most of Australia.
• Overnight temperatures are likely to be above average across most of Australia.

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Rainfall—Summary

Rainfall is likely to be below average for large areas Australia; above average in parts of eastern and far northern Queensland

December to February

• Rainfall is likely to be below average (60 to 80% chance) for parts of Western Australia, much of the Northern Territory, South Australia and Victoria, inland Queensland and New South Wales, and north-west Tasmania, with the highest chances of drier conditions in south-west Queensland.
• For much of Australia's far east, there is no clear signal in the rainfall forecast, meaning roughly equal chances of above or below average rainfall over the three months to February. Above average rainfall is slightly favoured (60 to 70% chance) for parts of Cape York Peninsula and eastern Queensland.
• Chances of above average rainfall have generally decreased over recent forecasts, with a dry signal now more pronounced for the month of December across much of the country.

Temperature—Summary

Warmer than average days and nights likely across most of Australia

December to February

• Maximum temperatures are likely to be above average (60% to over 80% chance) across most of Australia.
• Some areas have an increased chance of unusually high maximum temperatures¹ (over 50% chance) including parts of western and north-west Australia, western and central Victoria and central southern New South Wales.
• Minimum temperatures are likely to be above average (60% to over 80% chance) across most of Australia.
• There is an increased chance of unusually high minimum temperatures¹ (over 50% chance) across much of western and far northern Australia and parts of eastern Australia, with the strongest chances in the far tropical north (over 70% chance).

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

• 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 October 2025 the third warmest on record.
• SSTs for the week ending 30 November 2025 were warmer than average to the north-east and south-west of Australia, particularly in the Coral Sea and along much of the New South Wales and Queensland coasts. SSTs were cooler than average to the south-east and north of Australia.
• Forecasts for December to February show warmer-than-average SSTs are likely across much of the Australian region, especially in the east. Warmer oceans can provide increased moisture and energy, that can enhance the severity of storms, cyclones and rain systems.

• La Niña is underway. Observations in the tropical Pacific Ocean have been consistent with La Niña conditions since early October.
• The Bureau's model currently predicts that tropical Pacific Ocean temperatures are likely to remain at La Niña levels until early 2026 before returning to neutral. This timing aligns with most international models assessed.

• The negative Indian Ocean Dipole (IOD) event has been weakening steadily since early November and is near its end. The Bureau's model predicts a return to a neutral IOD during December, which is consistent with most international models.
• The Southern Annular Mode (SAM) index is negative, as of 29 November. Forecasts indicate SAM will remain negative until at least mid-December.
• The Madden-Julian Oscillation is likely to track across the Western Pacific at moderate to strong strength in the coming week, before weakening as it moves into the tropical Americas.
• The combination of these factors, including the state of SAM, MJO and SST patterns in our region, is likely contributing to the widespread dry signal across much of Australia during summer, particularly during December.