Australia in autumn 2020

In Brief

  • Nationally, a warmer than average autumn; but with strong geographical differences
  • Mean maximum temperature warmer than average for the north and west, cooler than average for the southeast
  • Mean minimum temperature warmer than average for much of the west, the northern tropics, and Tasmania; near-average for the majority of the mainland southeast
  • Autumn drier than average for Australia as a whole
  • Rainfall for the season was below average for much of Western Australia, areas of Australia's coastal northern tropics, and an area of southeast to central Queensland extending down parts of the New South Wales coastline
  • Wetter than average for much of Victoria and New South Wales away from the east coast, Tasmania, southwest Queensland and adjacent parts of South Australia and the Northern Territory, and for a large area of the inland Kimberley and Northern Territory
  • While large areas have received above average rainfall in one or more months this year, longer-term rainfall deficits still persist in many parts of Australia

Temperatures

Autumn was warmer than average for Australia, with the mean temperature 0.56 °C above average. The national mean maximum temperature was 0.61 °C warmer than average, and the mean minimum temperature was 0.51 °C warmer than average.

The mean temperature for autumn was the ninth-warmest on record for Western Australia. No other State or the Northern Territory placed amongst the ten warmest or coolest autumns on record.

The mean maximum temperature for the season was above or very much above average across most of Western Australia; the southwest and the north of the Northern Territory; and most of northern and southeastern Queensland. Maxima for the season were below average for most of Victoria and New South Wales, except along the east coast, and also for adjacent southern border regions of Queensland, much of the eastern half of South Australia, and eastern Tasmania.

A few sites observed their lowest autumn mean maximum temperature on record in Tasmania, Victoria, and New South Wales, although only one of these sites have more than 50 years of observations.

The mean minimum temperature for autumn was above average for most of Western Australia, excluding most of the Kimberley away from the coast, and parts of the South West Land Division and South Coast mostly away from the coast; for most of western South Australia and adjacent southwest of the Northern Territory; for much of the northern half of the Northern Territory and Cape York Peninsula in Queensland; an area of southwestern Queensland; and Tasmania. Minima for the season were only cooler than average for a few areas - the largest being around the northern end of Spencer Gulf in South Australia, and extending inland to around Lake Eyre South.

Thick cloud over Cape York Peninsula and parts of northern Queensland at the start of autumn brought some sites their warmest autumn night (highest daily minimum temperature) on record on 6 March.

In the north, the warmth across the season also included periods of individual warm days. A large number of stations in Western Australia observed late-season maximum temperature records, particularly at the start of April. Other sites in Western Australia, the Northern Territory, northern and eastern Queensland, and northeastern New South Wales also observed late-season heat records on other days during April.

The end of autumn brought a cool spell to eastern Australia from 20 to 26 May. A large number of sites in Queensland observed their coolest autumn day (lowest maximum temperature) on record, and a few sites their coolest autumn night (lowest autumn temperature on record), with the former having a number of long-term sites with more than 80 years of observations. In the south this period also saw a strong cold front cross Victoria in the early hours of 20 May, with a band of thunderstorms and strong winds, with at least one suspected tornado which damaged more than 100 houses close to Geelong. Meanwhile, in New South Wales a deep low pressure system over the Tasman Sea produced large waves along parts of the coast.


Areal average temperatures
Maximum Temperature Minimum Temperature Mean Temperature
Rank
(of 111)
Anomaly
(°C)
Comment Rank
(of 111)
Anomaly
(°C)
Comment Rank
(of 111)
Anomaly
(°C)
Comment
Australia 87 +0.61 92 +0.51 91 +0.56
Queensland 74 +0.52 84 +0.47 82 +0.49
New South Wales 16 −0.88 = 76 +0.16 49 −0.35
Victoria 30 −0.78 77 −0.07 48 −0.42
Tasmania = 32 −0.80 85 +0.23 = 56 −0.28
South Australia 62 +0.13 = 68 −0.05 70 +0.04
Western Australia 102 +1.43 10th highest = 101 +0.89 equal 10th highest 103 +1.16 9th highest
Northern Territory 85 +0.80 87 +0.61 91 +0.71

Rank ranges from 1 (lowest) to 110 (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

Rainfall for autumn was 19% below average for Australia as a whole, although there are marked differences in results across the nation.

Rainfall for the season was below to very much below average for most of Western Australia south of the Kimberley; areas around the border of northwest South Australia and the southwest of the Northern Territory; pockets of the tropical north of Australia; across much of central to southeastern Queensland; and parts of northeastern and far southeast New South Wales and adjacent far eastern Victoria.

Rainfall for autumn was above average for a broad area through the southeast and stretching through central Australia into northwestern Australia. Rainfall was above or very much above average for most of Tasmania, much of Victoria and New South Wales away from the east coast, Queensland Channel Country and Maranoa and Warrego districts, much of northeast and southeast South Australia, the far southeast of the Northern Territory, and a large area spanning the southern Kimberley and northern Interior District in Western Australia and adjacent parts of the northwest of the Alice Springs District in the Northern Territory.

The remnants of tropical cyclone Esther brought heavy rainfall to parts of northern Australia during early March, with flooding in western Queensland, and record-high autumn daily rainfall at some sites in Queensland and in northern Western Australia.

Autumn also started with a wet period in the south, with a large number of sites in Victoria, Tasmania, and a scattering in New South Wales observing record-high daily rainfall for autumn, mostly on 5 or 6 March. A few other sites in each State observed a record wet day for autumn at other points in the season.

A large number of sites in Victoria had their highest total autumn rainfall on record, with a very large number of other sites having their wettest autumn in at least 20 years. Several sites in Tasmania and New South Wales also observed their wettest autumn on record or wettest autumn for at least 20 years.


Area-average rainfall
Rank
(of 121)
Average
(mm)
Departure
from mean
Comment
Australia 46 97.6 −19%
Queensland 41 113.8 −30%
New South Wales 99 163.4 +14%
Victoria 105 199.7 +27%
Tasmania 104 422.9 +24%
South Australia 68 45.9 −18%
Western Australia 35 64.7 −28%
Northern Territory 54 103.2 −26%
Murray-Darling Basin 98 145.2 +22%

Rank ranges from 1 (lowest) to 120 (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 in autumn 2020
Hottest day 45.1 °C    at Onslow Airport (WA) on 1 March
Coldest day −2.7 °C    at Thredbo AWS (NSW) on 1 May
Coldest night −7.9 °C    at Liawenee (Tas.) on 25 May
Warmest night 31.9 °C    at Telfer Aero (WA) on 16 March
Wettest day 339.0 mm at Allingham Forrest Drive (Qld) on 11 March


Notes

The Seasonal 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 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 pm EST on Monday 1 June 2020. 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.


Further information

Media
(03) 9669 4057
Enquiries