Monday, 3 September, 2012 — Seasonal Climate Summary for Australia — Product Code IDCKGC2A00
Winter 2012 experienced generally close to normal maximum temperatures for much of Australia. Western Australia was the exception to this, with large parts in the top 10% of records. Minimum temperatures were cool over most of Australia, with much of northern and central Australia experiencing winter minimum temperatures in the bottom 10% of records.
Over most of the country, rainfall was not particularly exceptional for winter. Rainfall was generally below average across the western half of Australia and parts of the southeast, with the remainder of the country average to above average.
Winter maximum temperatures across Australia were generally close to normal, with the exception of WA. Maximum temperatures averaged across the nation were 0.42 °C above normal, and ranked as the 25th warmest winter of 63 years. WA had its eighth warmest winter daytime temperatures on record, with an anomaly of +0.95 °C.
Most of the country outside WA was within 1 °C of the long term average. Most of WA was at least 1 °C above average, with the exception of much of the southern coastline, and the Kimberley. Much of the western half of WA recorded decile 10 maximum temperatures for winter (top 10% on record), with a small area of the western Pilbara and Gascoyne (around Exmouth and Carnarvon) receiving their warmest winter daytime temperatures on record.
As is often expected with below average rainfall, much of the country experienced below normal night-time temperatures. For Australia as a whole, it was the third lowest mean winter minimum temperature on record, with an anomaly of −0.91 °C, the lowest since 1982. The NT had its coolest night-time mean temperatures on record (anomaly of −1.97 °C) beating the previous record set in 1976 (−1.87 °C). SA had its seventh coolest winter minima, and WA equal seventh. Tasmania was the only state to record above normal winter minimum temperatures.
Winter minima generally cooler than 1 °C below normal covered the Kimberley and eastern Interior parts of WA, most of the NT and outback SA, and parts of western Queensland and western NSW. Small areas near Wyndham in WA and Katherine in the NT experienced winter minimum temperatures near 3 ° C below normal. Large parts of Australia recorded minimum temperatures in the lowest 10% of records, such as the Kimberley and parts of the eastern Interior in WA, most of the NT, western and central SA, and scattered parts of both western Queensland and western NSW. Small areas near Wyndham, Derby and Giles in WA, Katherine in the NT and in the northern SA outback had record cold winter minimum temperatures.
|Areal average temperatures|
|Maximum Temperature||Minimum Temperature|
(out of 63)
(out of 63)
|Australia||39||+0.42||3||−0.91||3rd lowest; record is -1.18 (1976)|
|New South Wales||44||+0.69||13||−0.51|
|South Australia||31.5||+0.35||7||−0.80||lowest since 1997|
|Western Australia||56||+0.95||7.5||−0.75||lowest since 1976|
|Northern Territory||31||−0.06||1||−1.97||Previous record −1.87 (1976)|
*Anomaly is the departure from the long-term (1961–1990) average.
A fractional rank indicates that the value is tied for that rank.
Rainfall for winter 2012 was generally below average across the western half of Australia and parts of the southeast, and average to above average elsewhere. Neutral (neither El Niño or La Niña) conditions were in place for the winter period in the tropical Pacific, with signs of a possible El Niño eventuating in the coming spring. Typically neutral conditions in the tropical Pacific show no bias towards wet or dry conditions across Australia, and this is largely reflected in the rainfall pattern for winter.
Area-averaged rainfall for Australia was 53.2 mm (17% below normal), ranking as the 33rd driest winter of 113 years. Of the States, only Queensland and Victoria recorded above average winter rainfall. WA was the only state to fall in the top/bottom 10 of historical records, with its seventh driest winter on record (33.4 mm). Southwest WA (an area south of a line joining Jurien Bay and Bremer Bay) recorded its sixth driest winter after receiving a close to normal June, and a very dry July/August. July was particularly dry over southwest WA, with an area average of 38.9 mm, beating the previous record of 47.3 mm set in 1918. Perth rainfall was particularly significant, with the Perth Metro site recording only 27.8 mm for July, more than half of the previous record of 61.5 mm, set in 1876.
As is usual during the tropical dry season, much of the northern half of WA and the NT, along with the Gulf of Carpentaria coast of Queensland, received little or no rainfall for winter. This area of dryness extended further south than usual, with much of the southeast interior of WA and outback SA receiving close to no rainfall for winter. Other areas of below normal rainfall included southwest WA, an area of inland southern NSW extending into northern Victoria, and much of southern and eastern Tasmania. Southwest WA was particularly dry, falling into decile 1 in the historical record (lowest 10% of records). A large, sparsely populated region encompassing the southwest NT, western SA, and the WA interior also fell into decile 1.
Above normal winter rainfall was recorded across broad areas of Queensland, extending into parts of the Roper-McArthur district in the NT and the far northeast of SA. Above normal winter rainfall also occurred along parts of the southern coast, including an area covering most of southern Victoria and extending west to around Adelaide, as well as the coastal strip between Albany and Ravensthorpe in WA.
(out of 113)
|New South Wales||35||96.7||−17%|
*The mean is calculated for the 1961–1990 reference period.
|Australian weather extremes in winter 2012|
|Hottest day||38.5 °C at Fitzroy Crossing Aero (WA) on the 27th of August|
|Coldest day||−4.9 °C at Thredbo AWS (NSW) on the 6th of August|
|Coldest night||−14.0 °C at Charlotte Pass (NSW) on the 6th of July|
|Warmest night||26.0 °C at Coconut Island (Qld) on the 1st of June|
|Wettest day||203.4 mm at Reeves Knob (Vic.) on the 5th of June|
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.
This statement has been prepared based on information available at 12 noon EST on Monday 3 September 2012. 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.