Australia in May 2020

In brief

  • Nationally, May was cooler than average for Australia; the first month with a national mean temperature below average since October 2016
  • Both mean maximum and mean minimum temperatures were below average for Australia as a whole
  • Mean maximum temperature below average for most of the eastern half of mainland Australia, extending into the inland northeast of Western Australia
  • Mean minimum temperatures below average for much of mainland Australia away from the eastern seaboard and much of the north; above average for Tasmania and some pockets of coastal northern Australia
  • May rainfall below average for the country as a whole
  • Rainfall below average for much of the southern half of Australia
  • Rainfall above average for much of northern Australia, particularly in the Kimberley and central northern Queensland

Temperatures

For Australia as a whole the national mean temperature was 0.62 °C cooler than average for May. This was the first time a cooler than average mean monthly temperature has been observed for Australia nationally since October 2016, and is the coolest May since 2011.

Nationally, both the mean maximum and mean minimum temperature were below average for May. The mean maximum temperature for May was 0.37 °C below average, while the mean minimum temperature was 0.898nbsp;°C below average. No State or the Northern Territory placed amongst the ten warmest or coolest on record for May.

Maximum temperatures for May were below average across nearly all of Victoria and New South Wales except for some parts of the coast; the central and eastern two thirds of South Australia; most of Queensland except parts of the southeast, Peninsula, and areas through the west of the State; across the inland Kimberley and northern Interior District in Western Australia; and through much of the Northern Territory except the Top End, Gulf coast, and southwest.

Warmer than average mean monthly maximum temperatures for May were observed along parts of the northern coast in the Top End; in Western Australia in the southwesten Pilbara, western Gascoyne, and part of the south coast.

The mean minimum temperature for the month was below or very much below average for the southern half of Western Australia; for South Australia except the far southeast; the southern half of the Northern Territory and much of the area south of the Gulf of Carpentaria; for Queensland's Herbert and Lower Burdekin and Central Coast and parts of the far west and inland southern border regions of that State; for most of the western half of New South Wales; and large parts of Victoria mostly in the inland southwest, South Gippsland, and northern border regions.

Mean minimum temperatures for the month were above average for Tasmania, the northern tip of Cape York Peninsula in Queensland, a pocket of the southwestern Top End in the Northern Territory, and along much of the Pilbara coast in Western Australia.

Some sites in New South Wales set records for their lowest May mean daily maximum temperature, and some in South Australia set records for lowest May mean daily minimum temperature, although for both States these sites have less than 50 years of observations. Some sites in Victoria also observed their lowest May mean daily maximum temperature for at least 20 years.

A strong cold outbreak brought cool temperatures to southeastern Australia and significant snowfall in the Alps with widespread light falls over elevated locations in the first days of May.

Towards the end of the month thick cloud over parts of northern Australia, combined with a cold outbreak reaching into northern Queensland and bringing cool, dry southeasterly flow into the Northern Territory, saw cool days in the northern tropics and parts of central and southeast Queensland between the 22nd and 24th. A large number of sites in Queensland observed their coldest May day on record, with a few sites having more than 80 years of observations. In the Northern Territory many sites also recorded their coolest May day or their coolest May night on record. For Queensland as a whole, 23 May was the coldest May day on record (16.94 °C, previous record 17.44 °C on 25 May 2012). A few sites in Queensland also observed their lowest May temperature on record on the 24th.


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 = 38 −0.37 33 −0.88 32 −0.62
Queensland 28 −0.62 47 −0.65 40 −0.63
New South Wales = 26 −0.70 49 −0.72 40 −0.70
Victoria = 28 −0.75 38 −0.82 = 32 −0.78
Tasmania 74 +0.09 79 +0.26 78 +0.18
South Australia = 37 −0.56 14 −1.70 = 19 −1.12
Western Australia = 65 +0.43 33 −0.72 49 −0.14
Northern Territory = 27 −1.14 35 −1.02 = 30 −1.07

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

May rainfall was 31% below average for Australia as a whole. No State or the Northern Territory ranked amongst the 20 wettest or driest Mays on record. However, there was a significant geographical difference.

Rainfall was below average for most of the southern half of Western Australia, most of South Australia except parts of the northeast and southeast, the far south of the Northern Territory, most of Tasmania away from the west, and large areas of the eastern States from northern Victoria through western to central New South Wales, northeast and southeast New South Wales, and large areas of southern Queensland.

Rainfall was above average for much of northern Australia, including the Kimberley, northeastern Interior in Western Australia, the northern half of the Northern Territory except the Top End, and Queensland's northern tropics and Cape York Peninsula.

Northern coastal Queensland experienced heavy rain during the last third of May. The highest individual falls occurred when a surface trough and moist onshore flow brought locally heavy falls exceeding 250 mm around Mission Beach on the 20th. A few sites in Queensland had their highest May daily rainfall on record or their highest total May rainfall for at least 20 years.

The passage of strong cold fronts brought severe weather to Victoria in the early hours of the 20th, including reports of tornadoes near Donald and in Geelong, where more than 100 houses were damaged. This frontal system passed over New South Wales before a deep low formed over the Tasman Sea during the 22nd, remaining offshore of New South Wales over the following days weakening as it tracked northward by the 26th. Parts of the coast around Sydney and areas further south experienced damaging surf conditions.

Ex-tropical cyclone Mangga combined with an upper level trough and strong cold front approaching Western Australia on 24 May. Widespread severe weather resulted over much of southwest Western Australia between the 24th and 26th, including strong and gusty winds, abnormally high tides and storm surges, and severe coastal erosion.


Area-average rainfall
Rank
(of 121)
Average
(mm)
Departure
from mean
Comment
Australia 46 19.7 −31%
Queensland 71 21.7 −29%
New South Wales 38 22.1 −53%
Victoria 57 51.1 −21%
Tasmania 39 103.1 −25%
South Australia 21 7.2 −66%
Western Australia 67 24.0 −6%
Northern Territory 71 7.1 −48%
Murray-Darling Basin 35 21.1 −50%

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 during May 2020
Hottest day 38.3 °C    at West Roebuck (WA) on the 8th
Coldest day −2.7 °C    at Thredbo AWS (NSW) on the 1st
Coldest night −7.9 °C    at Liawenee (Tas.) on the 25th
Warmest night 28.8 °C    at Troughton Island (WA) on the 1st
Wettest day 301.8 mm at Bingil Bay (Qld) on the 21st


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 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.


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