Australia in summer 2020–21

In Brief

  • The national mean temperature for summer was slightly above average
  • The mean maximum temperature was below average for Australia as a whole
  • The mean minimum temperature was above average for Australia as a whole
  • Mean maximum temperatures were cooler than average for much of the mainland, but warmer than average for parts of the west coast, and parts of south-west Queensland and between Fraser Island and Rockhampton
  • Mean minimum temperatures were above average for the west and north-west of Western Australia, the north and east of the Northern Territory, all of Queensland, and the northern and eastern margin of New South Wales; they were below average for the northern interior of Western Australia and adjacent Northern Territory, areas of southern inland New South Wales, north-west Victoria, and south-east and northern South Australia
  • Rainfall for summer above average for Australia as a whole
  • Rainfall for summer above average for much of Western Australia, the north and west of the Northern Territory, western South Australia, far northern Queensland, most of New South Wales away from the west and south-east coast, south-west and north-east Victoria, and northern Tasmania
  • Rainfall for the season was below average for an area of eastern Queensland south of Mackay
  • Longer-term rainfall deficits still persist in many parts of Australia

Temperatures

Summer 2020–21 was warmer than average, with a mean temperature 0.06 °C above average. The national mean maximum temperature was below average at −0.28 °C, while the mean minimum temperature was 0.39 °C warmer than average.

Mean maximum temperatures were cooler than average for much of the mainland, but warmer than average for parts of the west coast, and parts of south-west Queensland and between Fraser Island and Rockhampton. The mean maximum temperature for the season was very much below average (decile 1, the lowest 10% of historical observations) for much of inland eastern Western Australia.

Mean minimum temperatures were above average for the west and north-west of Western Australia, the north and east of the Northern Territory, all of Queensland, and the northern and eastern margin of New South Wales; they were below average for the northern interior of Western Australia and some adjacent parts of the Northern Territory, areas of southern inland New South Wales, north-west Victoria, and south-east and northern South Australia. The mean minimum temperature for the season was very much above average (decile 10, the highest 10% of historical observations) for much of inland Queensland and the Cape York Peninsula and parts of coastal north-west Western Australia.

A very cold start to December saw a few stations near the west coast of Western Australia observed record low temperatures for summer on 1 December, associated with the passage of a tropical low.


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 43 −0.28 83 +0.39 = 66 +0.06
Queensland 71 +0.46 103 +1.23 9th highest 93 +0.85
New South Wales 44 −0.19 70 +0.23 57 +0.03
Victoria = 44 −0.34 64 +0.18 55 −0.07
Tasmania 50 −0.15 = 65 −0.04 = 61 −0.09
South Australia 38 −0.48 53 −0.12 48 −0.30
Western Australia 29 −0.53 70 +0.04 43 −0.24
Northern Territory = 44 −0.67 88 +0.51 = 62 −0.07

Rank ranges from 1 (lowest) to 111 (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 summer was 29% above average for Australia as a whole. Summer 2020–21 was the wettest since 2016–17, and December 2020 was the third wettest December since national records began in 1900.

Rainfall for summer was above average for much of Western Australia, the north and west of the Northern Territory, western South Australia, far northern Queensland, most of New South Wales away from the west and south-east coast, south-west and north-east Victoria, and northern Tasmania . Rainfall for the season was below average for an area of eastern Queensland extending south from Mackay.

Four named tropical cyclones occurred within the Australian region during summer 2020–21, with one (tropical cyclone Imogen) making landfall over the Queensland Gulf Country on 3 January. Imogen's remnants then combined with a coastal trough and low, resulting in widespread moderate rainfall across northern Queensland. A few stations observed their highest daily rainfall on record for summer.

Four unnamed significant tropical lows also brought heavy rain and some flooding to parts of northern Australia, including the Kimberley region in January and Gascoyne and Pilbara regions in early February. A number of stations observed their highest daily rainfall on record for summer.

Many stations in New South Wales set daily rainfall records across a number of events during summer. A number of stations set records for their highest total summer rainfall.

A cold front and low pressure trough brought tropical moisture into Victoria and southern New South Wales in late January to early February. A few stations in Victoria observed record-high daily rainfall for summer and daily totals approached or exceeded the average monthly rainfall across large areas.


Area-average rainfall
Rank
(of 121)
Average
(mm)
Departure
from mean
Comment
Australia 108 268.7 +29%
Queensland 74 349.8 +8%
New South Wales 101 215.7 +29%
Victoria 83 135.7 +14%
Tasmania 92 282.8 +18%
South Australia 88 67.4 +14%
Western Australia 104 230.2 +54%
Northern Territory 103 442.4 +39%
Murray-Darling Basin 87 160.4 +13%

Rank ranges from 1 (lowest) to 121 (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 summer 2020–21
Hottest day 48.7 °C    at Birdsville Airport (Qld) on 5 December
Coldest day 1.9 °C    at Thredbo AWS (NSW) on 6 and 7 December
Coldest night −6.0 °C    at Perisher Valley AWS (NSW) on 11 December
Warmest night 33.3 °C    at Windorah Airport (Qld) on 3 December
Wettest day 456.0 mm at Numinbah (Qld) on 13 December


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 1:30 pm EDST on Monday 1 March 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.


Further information

Media
(03) 9669 4057

Climate