Climate outlook for December to March

Long-range forecast overview

The long-range forecast for December to February shows:

• above average rainfall is likely for large parts of eastern Australia
• warmer than average days and nights are likely to very likely across most of Australia
• unusually high rainfall is likely for parts of the south-east and in far northern Queensland
• unusually high minimum temperatures are very likely for much of northern and eastern Australia.

Rainfall—Summary

Rainfall is likely to be above average for large parts of eastern Australia

December to February

• Rainfall is likely (60 to 80% chance) to be above average for much of eastern Australia, including much of Queensland, NSW, Victoria and eastern Tasmania.
• There is an increased chance of unusually high rainfall¹ for parts of south-eastern NSW, eastern Victoria, north-eastern Tasmania, and the Cape York Peninsula in Queensland.
• For the majority of WA, SA and the NT, rainfall is likely to be within the typical range for the season. South-eastern Queensland, including Brisbane is also likely to be within the typical seasonal range.
• Rainfall is likely (60 to 70% chance) to be below average for parts of western WA, including some regions in the Central Wheat Belt district.

¹Unusually high rainfall is defined as the highest 20% of December to February rainfall from 1981 to 2018.

Temperature—Summary

Increased chance of unusually warm days and nights across most of Australia

December to February

• Above average maximum and minimum temperatures are likely to very likely (60% to greater than 80% chance) across most of Australia.
• Maximum temperatures are likely to be within the typical range for the season for small parts of the central NSW coast and adjacent ranges.
• There is an increased chance of unusually high maximum temperatures² for most of Australia, excluding parts of eastern NSW and Victoria, with up to 4 times the normal chance across western WA and much of Tasmania.
• There is an increased chance of unusually high minimum temperatures² across Australia, particularly across the north and large areas in eastern Australia including Tasmania, with more than 3.5 times the normal chance.

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

We generate forecasts up to 4 months ahead using our long-range forecast model, ACCESS-S. The model simulates evolutions in the state of the atmosphere and oceans for the coming months. It uses millions of observations from satellites and instruments on land and at sea.

We monitor global and hemispheric climate indicators that can support our understanding of longer-term predictability. These indicators are mainly associated with interactions between the atmosphere and ocean.

For general information, our monitoring of these climate indicators shows:

• Global sea surface temperatures (SSTs) persist at near-record warm temperatures, just short of the record temperatures observed in 2023, but well above all other years since observations began in 1854. The sustained nature of this significant global ocean heat suggests that climate indicators such as El Niño–Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) may not behave or evolve as they have in the past.
• ENSO is currently neutral. Our climate model suggests ENSO-neutral conditions are likely to persist through to February 2025. Of the 6 other climate models surveyed, only one model suggests SSTs in the tropical Pacific are likely to exceed the La Niña threshold (below −0.8 °C) throughout November to February, which would be sufficient time to be classified as a La Niña event. All models forecast neutral ENSO values by March.
• The IOD index is currently negative. Models indicate that the IOD index will meet or exceed negative IOD thresholds in November, before returning to neutral levels in December.
• The Southern Annular Mode (SAM) is currently positive. Forecasts for late November and December are tending towards a positive SAM.