Australia in May 2010

In Brief

May 2010 for Australia was a generally unexceptional month, except in parts of northwestern Australia. Averaged nationwide, temperatures and rainfall were both slightly above normal.


Nationwide maximum temperatures were 0.23°C above normal. The most notable warmth was in the far northern tropics, and on the Pilbara coast in Western Australia. Days were about 1°C warmer than normal along the coast of the NT Top End and on northern Cape York Peninsula, sufficient to rank in the highest decile. Anomalies were slightly larger, reaching 2°C in places, in parts of the Pilbara. The only other areas which reached 1°C above normal were in the southeast, principally in northwestern Victoria and the Riverland of South Australia.

Below-average maximum temperatures were mostly confined to the north and east Kimberley region of Western Australia, and central areas of the Northern Territory, with anomalies below −1°C in a band from the east Kimberley to Tennant Creek. A few below-normal patches were also scattered in outback South Australia, inland Queensland and western New South Wales.

Overnight minimum temperatures were mostly well above normal in the northern tropics, below normal in the eastern states south of about Townsville, and close to normal in most other areas. Nationally minima averaged 0.20°C above normal. The northern tropics had exceptionally warm nights, with monthly temperatures at least 2°C above normal across most of the Kimberley, NT Top End and Queensland Gulf Country. Anomalies locally reached +4°C in the central Kimberley and the Victoria River district of the NT. Such temperatures were in the highest decile throughout, and reached record levels through much of the northwestern NT. Outside the northern tropics, the only area which was 1°C or more above normal was the far southeast of Western Australia.

Nights were cooler than normal in most of the eastern states (including Tasmania) from about Townsville southwards, except for Gippsland in Victoria. The below-normal minima also extended into most agricultural areas of South Australia. Anomalies were mostly modest, although a band extending southwest from Rockhampton into southern inland Queensland was 1-2°C below normal. Nights were also cooler than normal in most of western WA west of a Port Hedland-Southern Cross line. They were 1-2°C below normal in coastal areas between Bunbury and Geraldton, reaching the lowest decile locally around Perth.

Areal average temperatures
  Maximum Temperature Minimum Temperature
(out of 61)
Comment Rank
(out of 61)
Australia 36 +0.23 40 +0.20
Queensland 36 +0.19 27 −0.28
New South Wales 41 +0.74 25 −0.46
Victoria 46 +0.72 28 −0.43
Tasmania 50 +0.81 30 −0.14
South Australia 30 +0.14 44 +0.58
Western Australia 41 +0.57 39 +0.41
Northern Territory 19 −0.70 47 +0.69

*Anomaly is the departure from the long-term (1961-1990) average.

Temperature maps
Map of mean daily maximum temperature Map of mean daily maximum temperature anomalies Map of mean daily maximum temperature deciles
Map of mean daily minimum temperature Map of mean daily minimum temperature anomalies Map of mean daily minimum temperature deciles


National rainfall was 6% above the long-term average. It was a wet month over most tropical areas of Western Australia and the Northern Territory, north of a Port Hedland-Giles-Alice Springs line. In these regions, for which May is normally the first month of the dry season, rainfall was well above normal, reaching the highest decile in the Kimberley and northern interior of Western Australia, and the north and central west of the Northern Territory. Records were set in places, especially in the north and east Kimberley and in the Tanami Desert (NT), and the Northern Territory had its ninth-wettest May on record. The above-normal rainfall also extended into inland Queensland, in a band from Mount Isa to Longreach, and over much of South Australia from Adelaide northwards.

Other areas where rainfall was above average was in the Esperance region of southern Western Australia, the coast and adjacent ranges of New South Wales from Newcastle south to far eastern Victoria, parts of northeastern Tasmania (due to a single event at the end of the month), and much of southwestern New South Wales and adjacent northern border areas of Victoria. Only a few locations in these regions reached the highest decile, mostly west and east of Esperance.

Most other areas were drier than average, particularly in Queensland, where statewide rainfall was 48% below normal. Large parts of inland NSW, Victoria, Tasmania and western WA were also drier than normal. Whilst these areas were dry, they were not exceptionally so. Only a few patches were in the lowest decile, mostly in the southwest of Western Australia.

Areal average rainfall
(out of 111)
from mean*
Australia 80 30.3 +6%
Queensland 48 15.9 −48%
New South Wales 62 40.1 −15%
Victoria 46 47.3 −27%
Tasmania 26 92.2 −33%
South Australia 86 26.8 +26%
Western Australia 81 31.1 +21%
Northern Territory 103 38.0 +181%
Murray-Darling Basin 58 28.2 −33%

*The mean is calculated for the 1961-1990 reference period.

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

Australian weather extremes in May 2010
Hottest day 39.0 °C at Bidyadanga and Roebourne (WA) on the 4th
Coldest day −1.5 °C at Mount Baw Baw (Vic) on the 11th
Coldest night −10.2 °C at Liawenee (Tas) on the 22nd
Warmest night 28.6 °C at Troughton Island (WA) on the 5th and 6th
Wettest day 191.6 mm at Gray (Tas) on the 29th


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.

This statement has been prepared based on information available at 12 noon on Tuesday 1 June 2010. 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.

In the tables, fractional ranks denote tied values.

A new area-averaging method was adopted for rainfall in May 2009. Current and historical totals for Tasmania are substantially higher than under the old scheme, but differences for other states, and nationally, are negligible. The rankings and departures from mean shown here use the new method.

Further information

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