Australia in May 2021

In brief

  • May rainfall was well below average for Australia as a whole
  • Rainfall for the month was below average for most of northern Australia, the west of New South Wales and Victoria, Tasmania, southern South Australia, and the east of Western Australia
  • Rainfall for the month was above average for the west of Western Australia, eastern Victoria and south-eastern New South Wales
  • Mean maximum temperatures for May were warmer than average for most of Australia, but close to average for much of New South Wales, southern Queensland and South Australia
  • Mean minimum temperatures for May were warmer than average for most of Western Australia, but cooler than average for the Kimberley and large parts of the Northern Territory, and scattered areas of the eastern mainland, mostly in inland New South Wales

Temperatures

The mean temperature for May was 0.51 °C warmer than average for Australia overall.

The mean maximum temperature was above average for May at +1.04 °C. The mean minimum temperature was below average for May at −0.03 °C. None of the states or territories ranked in the top or bottom 10 warmest or coolest for their respective May temperatures.

Mean maximum temperatures for May were warmer than average for most of Australia, but close to average for much of New South Wales, southern Queensland, South Australia, and the inland south-west of Western Australia. Mean maximum temperatures more than 1 °C above average were observed for much of Western Australia except the inland south-west and north-west coast, most of Queensland and most of the Northern Territory south of the Top End.

Mean minimum temperatures for May were warmer than average for most of Western Australia, but cooler than average for the Kimberley. Cooler than average mean minimum temperatures for May were also observed in large parts of the Northern Territory, and scattered areas of the eastern mainland in western New South Wales and parts of adjacent states, and in the Maranoa District in southern Queensland.

The month began with particularly warm temperatures across the south-east, a number of sites in New South Wales, Victoria and Tasmania had their warmest May maximum temperature on record on the 2nd. A few sites in Victoria also observed their warmest May night on record on the 2nd, while a couple of sites in New South Wales also had a record warm night on the 7th.

High pressure systems brought clear skies and settled weather at times in the second half of the month for much of eastern Australia. Minimum temperatures in parts of inland New South Wales were more than 4 °C below average from the 16th to the 20th and more than 10 °C below average in the Queensland southern interior on the 17th, although no sites set records. Nights were colder still across the south-east between the 29th and 31st. Many sites in Victoria, New South Wales and south-east South Australia observed their coldest May night on record during that period.


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 = 93 +1.04 = 66 −0.03 87 +0.51
Queensland 86 +0.92 64 −0.15 77 +0.39
New South Wales 71 +0.66 55 −0.47 65 +0.10
Victoria 93 +0.93 61 −0.21 84 +0.36
Tasmania 82 +0.25 = 37 −0.51 = 57 −0.12
South Australia 82 +0.96 56 −0.27 = 71 +0.34
Western Australia 97 +1.32 90 +0.77 98 +1.05
Northern Territory 92 +1.03 38 −0.90 69 +0.07

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

May rainfall was 39% below average for Australia overall. Rainfall for the month was below average for most of northern Australia, the west of New South Wales and Victoria, southern South Australia, Tasmania, and the east of Western Australia. Rainfall for the month was above average for the west of Western Australia, eastern Victoria and south-eastern New South Wales.

May is typically the start of the northern Australia dry season and was particularly dry for the Northern Territory this year, with the Territory observing its ninth-driest May on record. Southern Australia May rainfall was around 25% below the 19611990 average, and has been above only once this century, in 2016.

At the start of the month, cold fronts and surface troughs brought rainfall in both south-east and south-west Australia. In the west, a trough over the north-west brought moisture in from the Indian Ocean, contributing to a broad cloudband and isolated thunderstorms along the coast. In the east, a cold front and low pressure system interacted with a coastal trough. Some sites in New South Wales, Victoria and Western Australia had their highest May daily rainfall on record from these events. Barrow Island and Roebourne Aero on Western Australia's Pilbara coast recorded unseasonably heavy daily rainfall of over 100 mm on the 5th and 6th respectively.

Between the 10th and 12th a complex low and cold front brought widespread rainfall over south-east Australia, including locally heavier daily falls in excess of 100 mm in the South Coast District in New South Wales, and East Gippsland in Victoria. A number of sites in both states observed daily rainfall records for May in the 24 hours to 9 am on the 12th.

Widespread rainfall in South Australia and Victoria was associated with a strong cold front on the 25th. Daily totals were generally between 10 and 20 mm but exceeded 30 mm in Victoria's north-east and the Mount Lofty Ranges near Adelaide. For parts of South Australia's Agricultural zone and western Victoria, this was the first notable rain for several months, but monthly totals were well below the May average. Ahead of the front on the 24th, strong and gusty northerly winds raised dust in many areas of South Australia.

A number of sites along the coast in New South Wales and Victoria had their highest total May rainfall on record or highest for at least 20 years.


Area-average rainfall
Rank
(of 122)
Average
(mm)
Departure
from mean
Comment
Australia 40 17.8 −39%
Queensland 17 7.0 −77%
New South Wales 48 27.7 −43%
Victoria 61 56.0 −16%
Tasmania 29 94.5 −30%
South Australia = 29 9.1 −57%
Western Australia 82 28.9 +9%
Northern Territory 9 0.8 −94% 9th lowest
Murray-Darling Basin 29 19.9 −55%

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 May 2021
Hottest day 38.1 °C    at Mandora (WA) on the 1st
Coldest day −3.9 °C    at Mount Hotham (Vic.) on the 15th
Coldest night −9.4 °C    at Perisher Valley AWS (NSW) on the 16th
Warmest night 27.4 °C    at Troughton Island (WA) on the 4th
Wettest day 195.0 mm at Braidwood (Mongarlowe (Leweston)) (NSW) on the 6th


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 1:00 pm EDST on Tuesday 1 June 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