Australia in October 2023

In brief

• Nationally-averaged October total rainfall for Australia was 65.4% below the 1961-1990 average, the fifth-driest October on record (since 1900) and the driest since 2002.

• Rainfall in October was below average for most of Australia.

• Rainfall was above average for most of eastern Victoria extending into adjacent parts of New South Wales.

• October 2023 was the driest October on record for Western Australia.

• Australia's national area-average mean temperature for October was 1.05 °C warmer than the 1961-1990 average.

• The national area-average mean maximum temperature  was 1.91 °C above average. The national area-average mean minimum temperature was 0.20 °C above average.

• Mean maximum temperatures for October were warmer than average for most of Western Australia, Queensland and New South Wales, the Top End of the Northern Territory, parts of eastern Victoria and South Australia and for northern Tasmania.

• Mean minimum temperatures for October were warmer than average for most of the southern two–thirds of Western Australia and parts of south-western Queensland and adjacent areas of northern New South Wales. Mean minimum temperatures were cooler than average for most of the Northern Territory and northern Western Australia, the south-eastern quarter of the South Australia extending into southern New South Wales and western Victoria, and parts of western Queensland.

• For the cool season (April to October), rainfall averaged across southern Australia (south of 26°S) was 153.4 mm, 32% below the 1961-1990 average.

• Cool season (April to October) mean maximum temperature for southern Australia (south of 26°S) was 1.79 °C warmer than the 1961-1990 average, the fourth-warmest on record, while the mean minimum temperature was 0.49 °C warmer than average. 

Further information and tables of records for each state and the Northern Territory can be found in the individual regional climate summaries, published on 3 November 2023.

Temperatures

The national mean temperature for October was 1.05 °C warmer than the 1961–1990 average for Australia as a whole.

The area-average mean maximum temperature for October was 1.91 °C warmer than the 1961–1990 average. Mean maximum temperatures for October were above or very much above average across most of Western Australia, Queensland and New South Wales, the northern third of the Northern Territory, parts of eastern Victoria and South Australia and for northern Tasmania. Daytime temperatures were amongst the highest 10% of historical observations (compared with all Octobers since 1910) for western and north-western parts of Western Australia, most of the Top End in the Northern Territory and large parts of Queensland and New South Wales. Mean maximum temperatures were the highest on record for parts of Western Australia's Pilbara, Gascoyne and South West Land Division. Many stations had their highest October mean maximum temperature on record.

Western Australia had its third-warmest October days on record, with the statewide mean maximum temperature 3.12 °C above average.

The national mean minimum temperature was 0.20 °C above the 1961–1990 average. Mean minimum temperatures were warmer than average for most of southern two thirds of Western Australia and parts of south-western Queensland and adjacent areas of northern New South Wales. Mean minimum temperatures were amongst the highest 10% of historical observations (compared with all Octobers since 1910) for much of Western Australia's Pilbara, Gascoyne, Goldfields, Southern Interior and South West Land Division districts and the highest on record for parts of the Gascoyne district and some stations had their highest October mean minimum temperature on record.

Mean minimum temperatures were cooler than average for most of the Northern Territory and northern Western Australia, most of the south-eastern quarter of South Australia extending into southern New South Wales and western Victoria, and parts of western Queensland. Mean minimum temperatures were amongst the lowest 10% of historical observations (compared with all Octobers since 1910) for most of Western Australia's Kimberley and Northern Interior, large parts of the Northern Territory  and an area in south-eastern South Australia. Some stations in these areas had their lowest mean minimum temperature for October on record.

The cool season (Aprill to October) mean maximum temperature for southern Australia (south of 26°S) was 1.79 °C warmer than the 1961–1990 average, the fourth-warmest on record. Mean maximum temperatures were warmer than average across southern Australia. The mean minimum temperature for southern Australia was 0.49 °C warmer than average. Mean minimum temperatures were warmer than the 1961–1990 April to October average for large parts of Western Australia, much of South Australia extending into southern Northern Territory and south-western Queensland, Tasmania and southern Victoria. Mean minimum temperatures were cooler than average for large parts of New South Wales.

Rank ranges from 1 (lowest) to 114 (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

For Australia as a whole, October rainfall was 65.4% below the 1961–1990 average, the fifth-driest on record for October since the national dataset began in 1900, and the driest since 2002.

All states and territories except Victoria had below average rainfall for October. For Western Australia, it was the driest October on record, with statewide rainfall 83.5% below average. For Queensland, it was the sixth-driest October on record, 83.6% below average.

October rainfall was below or very much below average for most of Australia. Rainfall was in the lowest10% of historical observations for October (compared with all Octobers since 1900) for south-western and large parts of eastern Western Australia, parts of the Top End and most of western Northern Territory, much of the south-eastern quarter of Queensland as well as areas of the Cape York Peninsula, and South Australia's North West Pastoral and Lower Eyre Peninsula districts. October rainfall was the lowest on record for parts of northern Wide Bay and Burnett and southern Central Highlands and Coalfields districts in Queensland. For northern Australia (north of 26°S), October was the driest start to its wet season period (October to April) since 2002.

Rainfall was above average for most of eastern Victoria extending into adjacent parts of New South Wales.

For the cool season (April to October) rainfall averaged across southern Australia (south of 26°S) was 153.4 mm, 32% below the 1961–1990 average. Rainfall was below average for much of western and southern Western Australia, most of South Australia's coastal areas extending inland, Victoria's South West, Central and East Gippsland districts, much of Tasmania and the eastern two-thirds of New South Wales and Queensland. Above average rainfall was limited to easternr parts of Western Australia and northern South Australia extending into the Northern Territory.

Significant weather and records

Heavy rain in Victoria

Between 3 and 5 October, a strong cold front and a low pressure system moved over south-eastern Australia bringing heavy rainfall, damaging winds, severe thunderstorms and showers mostly to Victoria and south-eastern New South Wales. The heavy rain was accompanied by cool daytime temperatures, 5 to 10 °C below average, while peak wind gusts of more than 100 km/h were recorded across elevated parts, with the strongest gusts of 139 km/h and 135 km/h recorded on the 3rd  at Mount Buller (Victoria) and Thredbo (New South Wales) respectively.

In the 24 hours to 9 am on the 4th, many stations in Victoria, some with more than 100 years of observations, had their highest October daily rainfall on record. The highest daily rainfall total during this event was reported for Mount Hotham which received 198.8 mm. This was a daily rainfall record not only for the current station at Mount Hotham, but also nearby closed sites (making a composite observation record of 73 years in the area).

Heavy rainfall led to flash flooding and widespread minor to moderate riverine flooding across north-eastern and eastern Victoria. There was isolated major flooding around Macalister, Mitchell and Ovens and King Rivers, which lead to inundation of homes, properties and businesses, as well as flooding of agricultural land.

Very warm across large parts of Australia

Hot, dry and sunny conditions under a large high-pressure system dominated large parts of Australia, resulting in above average temperatures. The intensity of warmth was unusual for both maximum and minimum temperatures, with highest temperatures for October on record and early season records (i.e. the highest temperature observed so early in the season) set at many stations. It was especially warm in New South Wales and parts of South Australia and Queensland between the 1st and 3rd, and across New South Wales and Queensland between the 20th and 25th, due to a northerly airflow preceding approaching cold fronts. High pressure systems directed very warm air to the south-west of Western Australia between the 6th and 8th and again between the 15th and 17th. A number of Western Australian stations, inluding Carnarvon and Geraldton Airports, had their highest October temperatures on record during this period.

Darwin Airport, which has 83 years of observations, recorded 38.0 °C  on the 15th, its 3rd highest October temperature on record. Severe to locally extreme heatwave conditions in parts of the Top End (Northern Territory) persisted for many days during the second half of October.

Extreme to catastrophic fire danger conditions

Hot and dry weather with strong, gusty winds resulted in extreme to catastrophic fire danger conditions for parts of Australia during the month. Many grassfires and bushfires were burning across northern and eastern parts of the country. A large fire in the Northern Territory's Barkly region, which started in September was finally brought under control on 18 October after burning around 2.8 million hectares of vegetation.

Fires in southern Queensland resulted in the evacuation of hundreds of residents in the last week of October. On the 31st, dry and very warm weather with maximum temperatures close to 40.0 °C  and gusty noth-westerly winds ahead of the southerly change elevated fire dangers to extreme through eastern and northern parts of New South Wales and the southeast interior of Queensland. Fire Weather Warnings for extreme fire dangers were issued for fire districts in the north-eastern New South Wales as well as for Greater Sydney and Illawara, and for Darling Downs and Granite Belt fire districts in Queensland. Smoke from ongoing fires led to periods of poor air quality across Queensland and New South Wales, including Brisbane, the Sunshine Coast and Sydney.

Wet and windy in south-eastern states

A series of cold fronts crossed south-eastern Australia between 12 and 16 October. These fronts brought gusty winds and showers to southern parts of the country and the cold air that followed the last front resulted in winter-like temperatures. As the front crossed New South Wales, it produced a strong southerly wind change rapidly moving up the coast, known colloquially as a 'southerly buster'. Wind gusts in excess of 100 km/h were recorded at some coastal and elevated locations.

A thunderstorm passed over Greater Melbourne on 12 October bringing hail to its northern parts, while some snow settled across alpine regions of Tasmania, Victoria and New South Wales across several days, with the last front bringing heavier falls on the 16th.

Thunderstorms across Tasmania

A low pressure system developed on 20 October south of the South Australian coast; it deepened and intensified while moving eastwards, bringing damaging winds, heavy rain, thunderstorms and showers to Tasmania. More than 40,000 lightning strikes were recorded as a line of thunderstorms moved across the state. Many sites in eastern Tasmania recorded daily rainfall totals of 20 to 40 mm to 9 am on the 22nd, with the highest daily total of 53.0 mm at Eaglehawk Neck station in the state's south-east. The Huon River reached minor flood levels, while wild storms left thousands of households without power.

Winter-like conditions in south-eastern Australia

A strong cold front crossed south-eastern Australia on 24 October with fresh to strong, gusty winds, showers, polar air and 'speckled' clouds in a strong southerly airstream behind it. On 25 and 26 October, large parts of South Australia, Victoria, Tasmania, New South Wales and south-western Queensland experienced daily maximum temperatures 4 to 8 °C cooler than average for October. Hail was reported at various locations across Victoria and Tasmania, while up to several centimetres of snow settled on elevated parts of southern and central Tasmania and alpine regions of Victoria.

Rank ranges from 1 (lowest) to 124 (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.