Australia in December 2025

In brief

• The national area-averaged mean temperature in December was 1.02 °C above the 1961–1990 average.
• Area-averaged mean temperature was above average for all states and territories except for Tasmania.

• For Western Australia, area-averaged mean temperature was 1.56 °C above average, the sixth-highest on record since national observations started in 1910. For South Australia, it was 1.61 °C above average, the tenth-highest on record.

• Australia's area-averaged mean maximum and mean minimum temperatures were 1.27 °C and 0.76 °C above the 1961–1990 average for December respectively.
• Mean maximum temperatures were average or above average for most of Australia and below average for a large area spanning the border between the Northern Territory and Queensland, and for parts of Tasmania.

• Mean minimum temperatures were average or above average for most of Australia and below average for northern parts of Western Australia and the Northern Territory, and areas scattered across the country's south-east.

• Australia's area-averaged December rainfall total was 38% above the 1961–1990 average.

• For Queensland, the area-averaged December rainfall total was 69% above average, the tenth-highest on record since national observations started in 1900.
• December rainfall was average or above average for most of Australia. It was below average for much of South Australia, parts of Western Australia and areas in the country's east.

 Further information and tables of records for each state and Territory are available in the individual regional climate summaries, published on 8 January 2026.

Temperatures

The national area-averaged mean temperature in December was 1.02 °C above the 1961-1990 average.

The area-averaged mean temperature for Western Australia and South Australia was the sixth-highest highest and tenth-highest on record for December, 1.56 °C and 1.61 °C above the 1961–1990 average respectively.

For Tasmania, area-averaged mean temperature was 0.73 °C below the December average, the lowest since 2008.

Australia's area-averaged mean maximum temperature in December was 1.27 °C above average. 

December mean maximum temperatures were above average to very much above average (in the highest 10% of all Decembers since 1910) for:

• most of Western Australia, South Australia and New South Wales
• parts of southern Queensland and the Northern Territory
• areas in northern Victoria.

December mean maximum temperatures were below to very much below average for:

• large areas of Queensland and the Northern Territory to the south of the Gulf of Carpentaria
• north-western Tasmania.

Australia's area-averaged mean minimum temperature was 0.76 °C above average.

Mean minimum temperatures were above to very much above average (in the highest 10% of all Decembers since 1910) for:

• much of Western Australia
• western and northern parts of South Australia
• areas in the south and north-west of the Northern Territory
• parts of southern and northern Queensland.

Mean minimum temperatures were the highest on record in parts of Western Australia's Pilbara, Gascoyne and Northern Interior districts and the Lasseter district in the Northern Territory.

Mean minimum temperatures were below to very much below average for large parts of northern Western Australia and the Northern Territory, most of Tasmania, and areas in western Victoria and south-eastern New South Wales.

Rank ranges from 1 (lowest) to 116 (highest). A rank marked with ’=‘ indicates the value is tied for that rank. Anomaly is the departure from the long-term (1961–1990) average.

Rainfall

The national area-averaged December rainfall total was 38% above the 1961-1990 average.

December rainfall was above average to very much above average (in the highest 10% of all Decembers since 1900) for:

• much of northern and western Queensland
• large parts of the Northern Territory
• scattered areas in the west and parts of northern Western Australia
• areas in central and north-western New South Wales
• parts of far north-eastern South Australia.

Rainfall was the highest on record for areas in Queensland's Gulf Country and North West districts, and many stations located there had their record highest rainfall total for December, including some stations with more than 100 years of data.

For Queensland, area-averaged December rainfall total was 69% above average, the tenth-highest on record since national observations started in 1900 and the highest since 2010.

Rainfall was below to very much below average (in the lowest 10% of all Decembers since 1900) for:

• south-western Northern Territory
• areas along the western and southern coasts of Western Australia
• parts of south-western Queensland and eastern New South Wales
• much of South Australia
• areas scattered across Victoria
• north-eastern Tasmania.

For South Australia, area-averaged rainfall was the lowest since 2019, around 64% below the December average.

Significant weather and records

Cool in the south-east

A cold front crossed south-eastern Australia on 1 December with showers and a cold southerly airstream in its wake. Most of south-eastern South Australia, Victoria and large parts of New South Wales experienced daily maximum temperatures up to 10 °C cooler than average for December, with localised areas more than 12 °C below average.  Mount Hotham (Victoria) equalled its record lowest daily maximum temperature for December of -0.7 °C , while Melbourne (Olympic Park) recorded 16.1 °C, its lowest maximum temperature for December since 2022 and the lowest maximum temperature on 1 December since 1996. The cold front also brought snow to alpine areas of Tasmania, Victoria and New South Wales.

Clear skies and light winds under the high pressure system that moved over south-eastern Australia following the cold front, resulted in low daily minimum temperatures on 2 and 3 December for large parts of south-eastern and eastern Australia. The lowest daily minimum temperature on 2 December was -4.0 °C at Thredbo AWS (New South Wales), while Canberra Airport (85 years of combined data) had its record low minimum temperature of -0.3 °C, the first below zero minimum temperature observed at this site in summer. On 3 December, as cold air penetrated further to the north, some stations in south-eastern Queensland had their record lowest minimum temperatures for December, including Mitchell Post Office (58 years of data) and Dalby Airport (34 years of data).

Thunderstorms in eastern Australia

Between 10 and 16 December, a series of low pressure troughs combined with a warm and humid airmass and triggered thunderstorms, some severe, across eastern parts of the mainland, most notably across New South Wales. On 11 December, thunderstorms impacted mostly central parts of New South Wales, bringing damaging winds, hail, heavy rain and flash flooding. A wind gust of 100 km/h was observed at Bourke Airport AWS (24 years of data), the record highest daily gust in December at this station, while hail was reported across wide areas around Mudgee and Dunedoo. Some stations reported heavy rain and flash flooding, including Coolah (34.4 mm in 30 minutes) and Angeldool (44.0 mm in 30 minutes). On 12 and 13 December, thunderstorms spread to eastern parts of New South Wales, south-eastern Queensland and eastern Victoria. Daily rainfall totals in the 24 hours to 9 am on 13 December of 15 to 40 mm were recorded across the Great Dividing Range, while some coastal areas had 50 to 80 mm, including up to 100 mm recorded locally around the Lake Macquarie region (New South Wales). On 15 December, thunderstorms brought locally heavy falls and flash flooding to the Sunshine coast and Wide Bay and Burnett districts (Queensland). In the 24 hours to 9am on 16 December, 169.8 mm was recorded at Tewantin RSL Park including 96.0 mm in 2 hours.

Tropical low 07U

Tropical low 07U started to develop in the northern Arafura Sea on 15 December. It moved slowly south towards northern Australia and approached the north-east Top End coast (Northern Territory) on 18 December, bringing increased shower and storm activity. 07U continued to move southward towards the southern Gulf of Carpentaria coast and on 20 December, it crossed the coast between Port Roper and Port McArthur (Northern Territory) bringing heavy rainfall to the coastal and adjacent inland areas of the Carpentaria (Northern Territory) and Gulf Country (Queensland) districts. The highest daily rainfall total during this event was 148.0 mm at Centre Island (Northern Territory) in the 24 hours to 9 am on 20 December.

Widespread rainfall in south-eastern Australia

On 21 December, a cold front interacted with a trough extending from north-west to the south-east Australia generating widespread rainfall and triggering thunderstorms, some severe.  In the 24 hours to 9 am on 22 December, daily rainfall totals exceeded 15 mm in far south-eastern South Australia, much of Victoria and parts of Tasmania and New South Wales, with falls greater than 25 mm in eastern Victoria, central western Tasmania and scattered areas of inland New South Wales. The highest daily rainfall totals were recorded in north-eastern Victoria, with the highest total of 186.8 mm at Dartmouth Reservoir. Thunderstorms also brought strong winds to eastern Victoria and inland New South Wales, including 115 km/h at Mount Buller (Victoria) and 96 km/h at West Wyalong Airport AWS (New South Wales), the record highest daily wind gust in December for this station.

Warm in the south-east of the country

On 4 December, daytime temperatures across southern parts of South Australia, Victoria extending into southern New South Wales, and Tasmania were 2 to 10 °C above average, as a high pressure system in the Tasman Sea directed hot northerly winds towards the south-east ahead of a cold front.  Strong to damaging winds developed ahead of the trough across eastern Tasmania, with many sites recording maximum daily wind gusts over 70 km/h and some over 100 km/h including 102 km/h at Hobart (Ellerslie Road). Some stations in eastern Tasmania had their highest daily wind gust on record for December including 93 km/h at Friendly Beaches (23 years of data). Many bushfires were burning across Tasmania on the 4th including a bushfire at Dolphin Sands in the states east.  

Between 14 and 21 December, warm conditions impacted large parts of southern Australia. A west coast trough that developed on 14 December, directed hot and unstable air from the interior of the continent towards south-western Western Australia. In the following days, warm conditions moved across southern parts of Western Australia to South Australia, southern Northern Territory, Victoria, Tasmania, New South Wales and south-western Queensland, pushed by the approaching cold front. Daytime temperatures were up to 12 °C above the December average. Nights were also warm with minimum temperatures up to 10 °C above average. Some stations had their record highest daily maximum temperature for December or their early season maximum temperature records. On 19 December, Sydney (Observatory Hill) in New South Wales peaked at 42.2 °C, equalling the December record for the city set in 1957.

Tropical Cyclone Grant

Tropical low 03U started developing in the Timor Sea from 11 December, before tracking south-westward into the Indian Ocean and staying well to the north-west of Western Australia's Pilbara coast. Moving westward it passed to the south of Christmas Island on 20 December bringing heavy rainfall to the island. 03U continued to slowly intensify, reaching tropical cyclone strength (Category 1) on 23 December and was named Grant. Tropical Cyclone Grant continued to move westward and passed by to the north of Cocos (Keeling) Islands in the morning on 25 December. Cocos Island Airport recorded daily rainfall total of 127.8 mm in the 24 hours to 9 am on 25 December, its 7th-highest daily rainfall total in December (125 years of rainfall data). The station recorded a wind gust of 102 km/h at 6.35 am on 25 December, the second-highest wind gust in December for this site (74 years of wind data). TC Grant continued to move westward, intensified to a Category 2 system on 26 December, and exited the Australian area of responsibility on 27 December.

Australian monsoon

From mid-December, there was increased tropical activity across northern Australia. From around 20 December, monsoonal conditions started to develop over the southern Indian Ocean and across Australian longitudes, and the onset of the Australian Summer Monsoon, as measured at Darwin, occurred on 23 December. The monsoon onset at Darwin is significant as it is typically one of the first areas in northern Australia to experience monsoonal conditions in the season.

Heavy rainfall in northern Queensland

The establishment of monsoon trough brought heavy rainfall and cooler conditions to much of the tropical north but especially to parts of northern Queensland. Between 24 and 31 December, a low pressure system embedded in the monsoon trough moved slowly from north-central parts of the Northern Territory towards north-western Queensland bringing heavy to locally intense rainfall to the region. Many stations in north-western Queensland recorded daily rainfall totals exceeding 100 mm and some had their record highest daily rainfall totals for December or for any month (annual). Seven-day rainfall totals (ending 9 am on 31 December) exceeded 300 mm at many stations in the Gulf Country district.

Heavy rainfall led to flash and riverine flooding. By 31 December, Major Flood Warnings were issued for Flinders River while Moderate Flood Warnings were issued for Norman, Cloncurry, Georgina and Western rivers. The flooding led to isolation of some communities with the closure of many roads.

Between 28 December and the end of the month, heavy rainfall impacted Queensland's north-east coast. A low pressure system embedded into a monsoon trough and enhanced onshore winds, brought moisture from the warm waters of the Coral Sea, resulting in high daily rainfall totals for the North Tropical Coast and Tablelands district. Daily rainfall totals at some stations exceeded 150 mm, with Bingil Bay (101 years of data) having its record highest daily rainfall for December and Innisfail Wharf Alert (26 years of data) for any month. Four-day rainfall totals (ending 9 am on 31 December) exceeded 700 mm at some stations, and the highest total of 1114.2 mm was recorded at Bingil Bay.

Severe Tropical Cyclone Hayley

Tropical low 08U developed in the Indian Ocean to the north of the Kimberley (Western Australia) on 28 December. Moving southward, it rapidly intensified, reached tropical cyclone strength early on 29 December and was named Hayley. While intensifying, Hayley started to move in the east-south-east direction, towards the western Kimberley coast, and late on the same day to early on 30 December reached a Category 3 intensity (Severe Tropical Cyclone strength). Hayley reached its peak intensity as Category 4 system early on 30 December, with sustained winds of 165 km/h and central pressure of 952 hPa. It made landfall later on 30 December on the Kimberley's northern Dampier Peninsula as a Category 3 system and further weakened.  As it crossed the coast, Severe Tropical Cyclone Hayley brought moderately heavy rainfall and damaging to destructive winds to the northern Dampier Peninsula and to the areas around its track. As the system moved inland it weakened rapidly and was downgraded to a tropical low on 31 December. Ex-tropical cyclone Hayley continued to bring gusty winds and heavy rainfall to the Kimberley in the following days.

Rank ranges from 1 (lowest) to 126 (highest). A rank marked with ’=‘ indicates the value is tied for that rank. Departure from mean is relative to the long-term (1961–1990) average.