Australia in May 2024

In brief

• The national area-averaged May rainfall total was 34.9% below the 1961–1990 average.

• Rainfall was below average for southern Australia and areas of northern and eastern Australia.

• Rainfall was above average for New South Wales and parts of central Australia and north-west Western Australia.

• Australia's national area-averaged mean temperature was 0.99 °C above the 1961–1990 average.

• Australia's area-averaged mean maximum temperature for May was 1.40 °C above the 1961–1990 average. Australia's area-averaged mean minimum temperature for May was 0.58 °C above the 1961–1990 average.

• Mean maximum temperatures were above average for most of the country and the highest on record for parts of the west coast of Western Australia and isolated pockets of north-eastern Victoria and the Top End of the Northern Territory.  

• Mean minimum temperatures were below average for southern parts of the mainland. Mean minimum temperatures were above average for western, eastern and northern areas of 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 5 May 2024.

Temperatures

Australia's national area-averaged mean temperature was 0.99 °C above the 1961–1990 average.

For Western Australia, it was the fifth warmest May on record, with the area-averaged mean temperature 1.71 °C above average and the warmest since 2005.

Australia's area-averaged mean maximum temperature for May was 1.40 °C above the 1961–1990 average. Victoria and Western Australia had statewide mean maximum temperatures in the top ten warmest Mays on record (since 1910).

Mean maximum temperatures were above average to very much above average (in the highest 10% of all Mays since 1910) for Victoria and Tasmania, most of Western Australia, Queensland and South Australia, an area of southern, inland and north-eastern New South Wales and a large area of Northern Territory's Top End and east. May daytime temperatures were the highest on record for Western Australia's coastal areas from the South Coast to Gascoyne districts and extending to surrounding inland areas and small isolated areas of north-eastern Victoria and the Top End of the Northern Territory.  

Australia's area-averaged mean minimum temperature for May was 0.58 °C above average.

Mean minimum temperatures were below to very much below average (in the lowest 10% of all Mays since 1910) for southern and inland areas of South Australia, western, central and northern Victoria, south-west New South Wales and a small pocket of south-eastern Western Australia. May minimum temperatures were the lowest on record for isolated pockets of coastal South Australia and western Victoria.

Mean minimum temperatures were above average to very much above average (in the highest 10% of all Mays since 1910) for western, southern and inland parts of Western Australia, most of the Northern Territory and Queensland, northern and coastal areas of New South Wales, a small area of north-eastern Victoria and eastern and southern coastal areas of Tasmania.

Rank ranges from 1 (lowest) to 115 (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, the area-averaged rainfall total for May was 34.9% below the 1961–1990 average.

Rainfall was below to very much below average (in the lowest 10% of Mays since 1900) for Tasmania, most of Victoria, southern South Australia extending to inland areas in the east, southern Western Australia and scattered parts of the west coast, Northern Territory's Top End, a large area of Queensland and south-eastern New South Wales on and west of the Great Dividing Range.

Rainfall was above average to very much above average (in the highest 10% of Mays since 1900) for much of New South Wales, and a large area extending from north-west Western Australia to central and southern Northern Territory, north-eastern South Australia and western Queensland. Rainfall was the highest on record for an isolated pocket of inland New South Wales.

Significant weather and records

Persistent and widespread rainfall across New South Wales

Coastal areas of New South Wales experienced persistent rainfall with several days of heavy rainfall for the first two weeks of the month, due to upper level systems and onshore flow aided by a slow moving high pressure system located south of the continent. From the 1st to 15th, coastal areas of New South Wales received 100 to 150 mm of rainfall, with an area between the South Coast to Hunter districts recording 300 to 400 mm of rainfall and isolated areas of the Illawarra recording rainfall totals of more than 400 mm. Many coastal sites also had their highest May monthly rainfall on record.

On the 2nd, an upper low pressure system developed over western New South Wales, moving eastwards towards the coast and generating up to 50 mm of rainfall in central areas in the 24 hours to 9 am on the 4th. The low pressure system combined with onshore flow producing daily rainfall totals of 50 to 100 mm in the 24 hours to 9 am on the 5th across the Illawarra, Sydney Metropolitan and Hunter districts, with the highest rainfall totals of over 100 mm in the Illawarra district. Several sites had their highest daily May rainfall on record. On the 6th the system moved north, and the Central Coast recorded daily rainfall totals of 50 to 100 mm. Heavy rainfall totals resulted in flash flooding in isolated pockets along the coast and the New South Wales State Emergency Services responded to close to 100 calls for emergency assistance in preparation for flash flooding.

The following week, another upper trough moved eastwards across western New South Wales, combining with onshore flow and generating widespread rainfall along the coast. Over 3 days, from 11th to 13th, the South Coast and Illawarra districts received 100 to 150 mm of rainfall, with isolated totals greater than 200 mm in the South Coast district, leading to minor flood warnings issued for the Deau River, Hawkesbury River and St Georges Basin.

Rainfall for southern parts of Western Australia

A cold front and low pressure trough triggered thunderstorms and heavy rainfall as it moved across south-west Western Australia early in the month with isolated daily rainfall totals on the 2nd and 3rd of 25 to 50 mm in the South West and Lower West districts.

The South West Land Division experienced strong winds, showers and severe thunderstorms, as a trough ahead of a cold front crossed south-west Western Australia on the 10th. A tornado impacted Bunbury and surrounding suburbs that afternoon and caused extensive damage to more than 100 properties and community buildings, with more than 200 homes were left without power. Wind gusts in excess of 90 km/h were recorded across some coastal sites and daily rainfall totals of 10 to 25 mm were recorded in the 24 hours to 9 am on the 11th.

At the end of the month, a cold front moved across south-west Western Australia, accompanied by isolated thunderstorms with small hail, strong wind gusts and widespread rainfall. Wind gusts across the Perth Metropolitan region on the morning of the 29th exceeded 100 km/h in some locations and the Perth Metro weather station recorded its highest wind gust for May at 80 km/h. Daily rainfall totals in the 24 hours to 9 am on the 29th were 10 to 15 mm across the south-west with isolated falls of 25 to 50 mm in the Lower West and South West districts. Bunbury had its highest daily rainfall for May at 72.6 mm (30 years of record). A waterspout also formed off the coast in Dunsborough in south-west Western Australia.

Cold mornings for parts of eastern and southern Australia

South Australia, Victoria, New South Wales, the Australian Capital Territory and Queensland experienced cooler than average May minimum temperatures for several days mid-month, in the wake of a cold front that moved across south-east and eastern Australia, which combined with a slow moving high pressure system. This produced persistent cooler southerly airflow that reached inland areas. Minimum temperatures were 6 °C below the May average across large areas of south-eastern and eastern Australia from the 18th to 23rd and several sites in southern South Australia recorded their lowest May minimum temperature on record on the 22nd.

North-west cloudband brings rainfall to large parts of the country

At the end of the month, a cold front interacted with tropical moisture and brought widespread rainfall to an area extending from north-west Western Australia to south-east Australia. The system originated off the coast of Western Australia and moved into the Northern Territory and South Australia, generating broad areas of rainfall. Parts of the Kimberley in Western Australia recorded 15 to 50 mm and Alice Springs Airport, in the Northern Territory, recorded 28.0 mm to 9am on the 30th, its highest May daily total since 2004.

The cold front moved across south-eastern Australia on the 30th, with warm northerly winds strengthening ahead of the front resulting in damaging winds gusts over elevated areas of southern New South Wales, Victoria and Tasmania. Several sites across south-eastern Tasmania, and elevated areas across north-eastern Victoria and south-eastern New South Wales recorded wind gusts up to 100 km/h, including Thredbo (New South Wales) with its equal highest wind gust on record for May at 146 km/h.  

Widespread light to moderate rainfall was associated with the passing of the cold front and associated trough with a large band of rainfall extending from the Kimberley in Western Australia to south-eastern states. The heaviest rainfall totals of 50 to 100 mm were recorded across parts of the northern Kimberley in Western Australia and north-eastern Victoria in the 24 hours to 9 am on the 31st. Many sites across north-eastern Victoria had their highest daily rainfall for May, including Mount Hotham with 115.8 mm (32 years of record), Falls Creek with 84.6 mm (33 years of record) and Mansfield with 61.4 mm (124 years of record).

Rank ranges from 1 (lowest) to 125 (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.