Australia in March 2021

In brief

  • Rainfall was above average for Australia as a whole
  • Rainfall for the month was above or very much above average for much of the east, central and north-west of Australia, as well as the west of Western Australia
  • Rainfall for New South Wales was more than double the March average, coming in as the second-wettest March on record for the state, behind March 1956 — extensive areas of flooding resulted
  • Rainfall for the month was below average for the southern half of Queensland's Cape York Peninsula
  • Mean maximum temperatures for March were cooler than average for large areas of mainland Australia extending from the north-west through to New South Wales and Victoria; however, they were warmer than average for much of the northern half of Queensland extending into the Wide Bay and Burnett District, pockets of the Northern Territory, and parts of the southern half of Western Australia
  • Mean minimum temperatures for March were warmer than average for most of Queensland, the northern half of the Northern Territory, and the south-western quarter of Western Australia; cooler than average for some smaller areas, mostly across central New South Wales and in the Pilbara and Kimberley in Western Australia

Temperatures

The national mean temperature for March was 0.21 °C warmer than average for Australia as a whole.

The mean maximum temperature was close to average for March at +0.03 °C. The mean minimum temperature was above average for March at +0.39 °C. None of the States or Territories ranked in the top or bottom 10 warmest or coolest for their respective maximum or minimum March temperature ranks.

Mean maximum temperatures for March were cooler than average for large areas of mainland Australia extending from the north-west of Western Australia, taking in the East and West Kimberley, Pilbara, and north-eastern Interior District, through the south-west of the Northern Territory and far north of South Australia, to New South Wales, and also covering most of Victoria except the far west, and the southern border region of Queensland. This area of cooler than average mean maximum temperatures largely followed the band of above average rainfall.

Maximum temperatures for the month were very much below average (decile 1) for large parts of New South Wales, mostly along and inland of the Great Dividing Range, extending into parts of the north-west of the state.

The mean maximum temperature for March was warmer than average for much of the northern half of Queensland, extending along the coast into the Wide Bay and Burnett District, and also for pockets of the Northern Territory in the Top End and east of Tennant Creek, and for parts of Western Australia in the western Gascoyne, western Interior, and along the southern coast.

The mean minimum temperature for the month was above average for much of the west and inland south of Western Australia, the northern half of the Northern Territory, far north-east New South Wales, and most of Queensland away from the Channel Country District and central Cape York Peninsula. Mean minimum temperatures were below average for some areas, including inland New South Wales away from the west, and in Western Australia in the central Pilbara and between the central Kimberley coast and the north-east of the Interior District.

Cool days were observed across parts of New South Wales and Queensland between the 14th and 17th associated with the passage of a cold front and surface trough. Daytime temperatures were more than six degrees cooler than average in broad areas, with some stations in Queensland and New South Wales observing their coldest March day (lowest maximum temperature) on record, although only one site has observations spanning more than 30 years.

In Western Australia cool days were observed in the Kimberley and eastern Pilbara on the 19th and 20th, with a few stations having their coldest March day on record. Conversely, the end of the month saw low-intensity heatwave conditions across parts of the inland southern Gascoyne and eastern South West Land Division, and severe heatwave conditions in the Southeast Coastal District. A small number of stations observed their warmest March night on record on the 30th.


Areal average temperatures
Maximum Temperature Minimum Temperature Mean Temperature
Rank
(of 112)
Anomaly
(°C)
Comment Rank
(of 112)
Anomaly
(°C)
Comment Rank
(of 112)
Anomaly
(°C)
Comment
Australia 60 +0.03 77 +0.39 = 62 +0.21
Queensland 74 +0.59 96 +0.98 92 +0.79
New South Wales 17 −1.34 57 −0.16 31 −0.74
Victoria = 33 −1.02 62 −0.20 = 45 −0.60
Tasmania = 78 +0.19 83 +0.25 = 79 +0.22
South Australia 51 −0.07 64 +0.22 60 +0.08
Western Australia = 57 +0.04 68 +0.12 63 +0.08
Northern Territory 66 +0.35 76 +0.68 73 +0.52

Rank ranges from 1 (lowest) to 112 (highest). A rank marked with ’=‘ indicates the value is tied for that rank. Anomaly is the departure from the long-term (1961–1990) average.


Temperature maps
MeanAnomalyDeciles
Mean
daily
maximum
temperatures
Map of mean daily maximum temperature Map of mean daily maximum temperature anomalies Map of mean daily maximum temperature deciles
Mean
daily
minimum
temperatures
Map of mean daily minimum temperature Map of mean daily minimum temperature anomalies Map of mean daily minimum temperature deciles
Mean
daily
temperatures
Map of mean daily temperature Map of mean daily temperature anomalies Map of mean daily temperature deciles

Rainfall

March rainfall was above average for Australia as a whole.

Rainfall for the month was above or very much above average for most of New South Wales and the southern half of Queensland, the southern half and west of the Northern Territory, the northern half and central south of South Australia, the Kimberley and much of the west of Western Australia, parts of central and eastern Victoria, and the east coast of Tasmania.

Rainfall for New South Wales was more than double the average rainfall for March, coming in as the second-wettest March on record for the state, behind March 1956. Rainfall for the month was in the highest 10% of historical records (decile 10) for most of the eastern half of the state and much of the north, extending into parts of southern Queensland and Central Australia. Areas of extensive flooding resulted throughout eastern New South Wales.

Rainfall for the month was below average for the southern half of Queensland's Cape York Peninsula, and a few small pockets in both the Top End in the Northern Territory and south-east South Australia.

A deep surface trough extended from north-west Queensland to the inland south of the state from the 14th, and produced widespread moderate falls in north-west, central, and southern parts of the state. On the 17th, an isolated, extremely heavy daily rainfall total of 550 mm was recorded at Byfield Childs Road in the Capricornia District in Queensland, with further falls over 100 mm the following day.

From around the 17th, a blocking high pressure system became established in the Tasman Sea. Extreme multi-day rainfall and flooding affected many parts of eastern and central Australia from 17 to 26 March 2021, as a result of this split-flow blocking high pressure system in the Tasman Sea, and a low-pressure system off northwest Australia feeding moist tropical air into eastern Australia as it tracked into the south-east over the 10-day period. In coastal New South Wales moist onshore flow contributed to the heaviest falls, supported at times by surface troughs and a small low pressure system between the 19th and 20th. More detail on the synoptic situation will be provided in a forthcoming Special Climate Statement, while further details of flooding is included in the Queensland and New South Wales regional climate summaries.

Heavy rainfall during this period extended from central Australia to northern inland New South Wales, leading to widespread significant flooding in coastal New South Wales, and some adjacent parts of south-east Queensland and eastern Victoria. There was also significant flooding on some inland rivers in northern New South Wales and southern Queensland, as well as in eastern Tasmania.

Some stations in Queensland and Victoria had their highest March daily rainfall on record during the event (with two stations at Queensland having records longer than 100 years), as did a few in Tasmania, but by far the largest number of records were in New South Wales where more than 50 stations set daily rainfall records for March, with nine of these having an observation period of more than 50 years, and three of these more than 100 years.

A very large number sites across northern and eastern New South Wales also had their highest total March monthly rainfall on record, with six of these having an observation period of more than 100 years and an additional 16 with an observation period of more than 50 years. Some sites in Queensland and a few in Victoria also had their highest total March rainfall on record or their highest total March rainfall for at least 20 years.

In Western Australia a broad trough and a weak low pressure system tracked over the state's west and south, and produced thunderstorms and showers with moderate rainfall early in the month. A few stations in the South West Land Division had their highest March daily rainfall on record on the 3rd or 4th. Many stations had their wettest March on record or wettest March for at least 20 years.

In the Northern Territory some stations in the Gregory District had their wettest March day on record, while other sites in the Gregory District, as well as sites in the south-west of the Territory, had their highest total March rainfall for at least 20 years.


Area-average rainfall
Rank
(of 122)
Average
(mm)
Departure
from mean
Comment
Australia 99 80.8 +28%
Queensland 68 92.1 −1%
New South Wales 121 136.3 +153% 2nd highest (record 177.6 mm in 1956)
Victoria 85 48.0 +15%
Tasmania 83 103.4 +19%
South Australia 103 33.4 +66%
Western Australia 91 64.5 +48%
Northern Territory 84 102.9 +1%
Murray-Darling Basin 119 95.6 +123% 4th highest (record 159.3 mm in 1956)

Rank ranges from 1 (lowest) to 122 (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.


Rainfall maps
TotalsPercentagesDeciles
Total
rainfall
Map of total rainfall Map of percentage of normal rain Map of rainfall deciles


Australian weather extremes during March 2021
Hottest day 43.0 °C    at Oodnadatta Airport (SA) on the 2nd
Coldest day 3.0 °C    at kunanyi (Mount Wellington Pinnacle) (Tas.) on the 2nd
Coldest night −5.5 °C    at Perisher Valley AWS (NSW) on the 3rd
Warmest night 30.1 °C    at Giles Meteorological Office (WA) on the 5th
Wettest day 550.0 mm at Byfield Childs Road (Qld) on the 17th


Notes

The Monthly Climate Summary is prepared to list the main features of the weather in Australia using the most timely and accurate information available on the date of publication; it will generally not be updated. Later information, including data that has had greater opportunity for quality control, will be presented in the Monthly Weather Review, usually published in the fourth week of the following month.

Climate Summaries are usually published on the first working day of each month.

This statement has been prepared based on information available at 1:30 pm EDST on Thursday 1 April 2021. Some checks have been made on the data, but it is possible that results will change as new information becomes available, especially for rainfall where much more data becomes available as returns are received from volunteers.

Long-term averages in this statement and associated tables are for the period 1961 to 1990 unless otherwise specified. Temperature area averages are derived from the ACORN-SAT version 2 dataset. Rainfall area averages, along with rainfall and temperature maps, are derived from the AWAP dataset.


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