The Bureau of Meteorology (BOM) has issued its long-range forecast for the 2025 summer season and it shows summer days and nights are likely to be warmer than average across most of Australia.

For much of NSW and the ACT, the BOM suggests rainfall for December is likely to be below average, and the forecast for January and February currently shows there are near-equal chances of above or below average rainfall.

The forecast for summer as a whole currently shows below average rainfall is likely for large parts of inland NSW, while summer temperatures are likely to be above average during the day and overnight for much of the state and the ACT.

There is an increased chance of unusually high overnight temperatures in the ACT and some central and eastern parts of NSW,

The latest conditions in the tropical Pacific indicate a relatively weak La Nina event is underway, the BOM says, but this is expected to be short-lived. The BOM rainfall forecast currently suggests there will be little overall influence from this La Nina event.

The period between October and April is traditionally Australia's peak time for severe thunderstorms, tropical cyclones, flooding, heatwaves and bushfires, the BOM says.  Severe thunderstorms are more common from October to December, bringing the risk of heavy rainfall, damaging winds, large hail and the risk of flooding anywhere in the country.

Australia's fire agencies advise there is an increased risk of fire for parts of Victoria, western and southern Western Australia, and parts of central northern NSW.

Nationally, summer rainfall is likely to be below average for parts of the west and inland parts of the east. However, for much of the east coast and south, the summer forecast does not currently show a clear above/below average rainfall signal.

The BOM's forecast will evolve over summer and the seasonal forecast will be updated every week. The community can stay up to date with the latest long-range forecast via the BOM website.