Australia in July 2023

In brief

• Nationally-averaged July total rainfall for Australia was close to average.

• Rainfall for July was above average for much of the northern half of Australia.
• Rainfall was below average for southern two thirds of Western Australia, most of South Australia, eastern New South Wales, Victoria and eastern Tasmania. 
• Australia's national area-average mean temperature was 1.19 °C above the 1961-1990 average, the ninth-highest on record (since 1910) for July.
• The warmest July on record for Tasmania.
• Area-average mean maximum temperature for July was 1.23 °C above average nationally. The national mean minimum temperature was 1.15 °C above average.
• Mean maximum temperatures for July were above average for large parts of eastern and southern Australia. Mean maxima were cooler than average for parts of the Northern Territory extending into north-eastern Western Australia and parts of western Kimberley. 
• Mean minimum temperatures for July were warmer than average for much of the eastern two thirds of Australia and cooler than average for large parts of southern Western Australia.

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 August 2023.

Temperatures

The national mean temperature was 1.19 °C  above the 1961-1990 average for July, the ninth-warmest on record since national observations began in 1910. For Tasmania it was the warmest July on record, at 2.02 °C above average. New South Wales, Victoria and South Australia were all in the top 10 warmest Julys on record.  

Australia's area-averaged July mean maximum temperature was 1.23 °C above average. Mean maximum temperatures were above average for large parts of eastern and southern Australia. Daytime temperatures were amongst the highest 10% of historical observations (compared  with all Julys since 1910) for parts of northern and south-eastern Queensland, most of New South Wales and Victoria, Tasmania and parts of eastern and south-western South Australia extending into south-eastern Western Australia. Mean maximum temperatures for July were the warmest on record for most of Tasmania excluding the north-western part, for south-eastern New South Wales and much of eastern Victoria. Many stations had their highest mean maximum temperature for July on record.

For Tasmania, the July statewide mean maximum temperature was 1.40 °C above the 1961-1990 average, the warmest on record. For New South Wales this July was the fourth-warmest on record, for Victoria the sixth-warmest on record and for South Australia the tenth-warmest on record.

Clear skies and light winds resulted in high daytime temperatures in parts of northern and eastern Australia in July. Northerly airflow brought unusually mild daytime temperatures to Tasmania between the 1st and 3rd, and again on the 13th and some stations had their highest July temperature on record on these days. 

Mean maximum temperatures were cooler than average for parts of the Northern Territory extending into north-eastern Western Australia and parts of western Kimberley.

The national mean minimum temperature was 1.15 °C above average. Mean minimum temperatures for July were warmer than average for much of the eastern two thirds of Australia. Mean minimum temperatures were amongst the highest 10% of historical observations (compared with all Julys since 1910) for Tasmania, large parts of northern and south-western Queensland, north-eastern South Australia extending into adjacent parts of the Northern Territory and New South Wales, and for southern Victoria. Mean minimum temperatures for July were the warmest on record for Tasmania, parts of the South West district in Victoria and for an area spanning the border between Queensland and South Australia.

Tasmania's statewide mean minimum temperature was 2.63 °C above the 1961-1990 average, the warmest on record since observations begun in 1910.  For Queensland this July was the seventh-warmest on record.

With the combination of a mild northwest wind and cloudy skies, much of Tasmania had a very warm night on the 13th. Many sites had their highest daily minimum temperature for July on record. Hobart had its warmest July night on record reaching  13.0 °C (137 years of observations).

Mean minimum temperatures for July were cooler than average for large parts of southern Western Australia and in the lowest 10% of historical observations (compared with all Julys since 1910) for parts of the Gascoyne and South East Coastal districts. Several sites had their lowest mean minimum temperature for July on record.

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, July rainfall was 1.1% above the 1961-1990 average.

Victoria's rainfall was about 48% below average, the driest July since 1997. For the Northern Territory as a whole, it was the ninth wettest July on record and the wettest since 2010. 

Rainfall was very much above average (in the wettest 10% of historical observations) for much of Kimberley (Western Australia), Gregory, Barkly, and parts of Tanami, Carpentaria and  Simpson districts (Northern Territory), most of western Queensland and for pockets of Queensland coast. Many stations across these areas had their highest July total rainfall on record. 

A low pressure trough in the upper atmosphere dragged tropical moisture from the Timor and Arafura Seas southwards, resulting in significant rainfall in these areas in the first four days of the month.

Rainfall was below average for southern two thirds of Western Australia, most of South Australia, eastern New South Wales, Victoria and eastern Tasmania. July rainfall was very much below average (in the driest 10% of historical observations) for the South West Land Division, and parts of the Gascoyne, Goldfields and Southern Interior districts in Western Australia, parts of South Australia's West Coast and south-eastern areas, much of central and eastern Victoria, the far south-eastern New South Wales and parts of eastern Tasmania. July rainfall was the lowest on record for eastern parts of Victoria's Central district around Melbourne and in East Gippsland.

Significant weather and records

Unseasonal rainfall in northern Australia

Unseasonal rainfall that started late in June continued during first five days of July as a low pressure trough in the upper atmosphere re-intensified, dragging tropical moisture from the Timor and Arafura Seas southwards. Clouds and rainfall extended from the far northern Western Australia to central Northern Territory moving into Queensland. These regions are typically drier at this time of the year, with average July totals generally less than 10 mm.

To 9am on the 1st, many stations in the Kimberley district in Western Australia and adjacent parts of the Gregory district in the Northern Territory had daily rainfall totals in excess of 40 mm. In the following three days, rainfall extended further through central Northern Territory into western and central Queensland, with daily rainfall totals generally between 30 and 50 mm. Many stations with more than 30 years of observations had their highest July daily rainfall on record – in northern Western Australia and the Northern Territory on the 1st and 2nd, and in Queensland on the 3rd and 4th.

Cloudy skies and rainfall resulted in daily maximum temperatures more than 10 °C below average in parts of northern Western Australia, most of the Northern Territory and parts of western Queensland over this period and many stations had their lowest daily maximum temperature for July on record on the 1st and 2nd.

Damaging winds

A strong cold front crossed south-eastern Australia on the 7th and 8th, with showers, damaging winds, low temperatures and snow on elevated areas. With a high pressure ridge stretching across central parts of the mainland, a deep low pressure system to the south of the country and a strong change of pressure between them, a cold front brought strong winds with gusts in excess of 90 km/h for south-eastern South Australia, much of Victoria, Tasmania and southern New South Wales. The strongest wind gusts of 135 km/h at Neptune Island (South Australia), 137 km/h at Hogan Island (Victoria) and 143 km/h at Maatsuyker Island Lighthouse (Tasmania) were observed on the 8th.

Daily rainfall totals of more than 40 mm were recorded at many  stations to 9 am on the 8th and 9th and Minor to Moderate flood warnings issued for some catchments in north-east Victoria and north-west Tasmania, while more than 20 cm of snow fell in Alpine areas.

Very strong north-westerly winds impacted southern Tasmania at the end of the month during the passage of a cold front, causing extensive power outages. The  strongest wind gusts were recorded on the 31st when 200 km/h, 169 km/h and 146 km/h were recorded at Maatsuyker Island, Scotts Peak Dam and Low Rocky Point respectively, and were the highest daily wind gusts on record for any month for these stations.

Warm days and nights for Tasmania

Northerly airflow brought unusually mild daytime temperatures to Tasmania between the 1st and 3rd, and again on the 13th and some stations had their highest July temperature on record on these days. The combination of a mild northwest wind and cloudy skies also resulted in a very warm night on the 13th. Many Tasmanian sites had their highest daily minimum temperature for July on record. Hobart had its warmest July night on record reaching 13.0 °C (137 years of observations). 

Cold mornings

A number of fronts crossed southern Australia during July bringing typical winter weather conditions – rainfall, strong to damaging winds, large waves and low temperatures. However, most of the continent was under the influence of high pressure systems or high pressure ridges, which brought settled and dry conditions. Clear skies and light winds resulted in low daily minimum temperatures across southern and eastern parts of the country. Some stations in southern Queensland and eastern New South Wales recorded sub-zero minimum temperatures between the 9th and 11th, while on the 19th and 20th many stations in south-eastern South Australia, Victoria and New South Wales recorded sub-zero daily minimum temperatures and some stations had their lowest minimum temperature for July on record. Areas of morning fog and frost impacted large parts of southern and eastern Australia on many days during the month.

The minimum temperature of -10.8 °C at Glen Innes Airport AWS (New South Wales) on the 20th was Australia's lowest temperature recorded this year, and the lowest temperature outside the south-east alpine regions since 2019. Between the 16th and 27th, Canberra experienced 12 days with sub-zero minimum temperatures, the first time since 1994.

Wet and cool weather for eastern Quensland

From 23 July, a surface low pressure trough nearthe  south-eastern Queensland coast which slowly drifted northward, and a cut-off low in the upper atmosphere, generated showers around parts of the east coast and adjacent inland areas. The heaviest rainfall impacted Queensland's Capricornia, Central and North Tropical Coasts where many stations recorded four-day rainfall totals to 9am on the 27th of more than 100 mm, exceeding their July average rainfall which is generally between 25 and 50 mm. Cool daytime temperatures extended through eastern Queensland due to southerly airflow and increased cloud cover. 

A warm end to the month

The last five days of July saw mild daytime temperatures across Australia, with daily maximum temperatures 2 to 8 °C above the July average. Several stations in New South Wales and Victoria had their highest daily maximum temperature for July on record between the 28th and 30th.

Night-time temperatures were also above average across much of the country, mostly in the central and eastern parts where daily minimum temperatures were more than 8 °C above average in some areas.

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.