Perth in summer 2012/2013: One of hottest summer

This statement was prepared before all data for the period were available. This may affect some of the statistics presented.
  • Rainfall: near average to above average
  • Maximum temperature: very-much-above-average, hottest summer for Perth Metro
  • Minimum temperature: above average

Rainfall

Above average rainfall in December, an average January and February resulted in near average to above average rainfall totals across the Perth metropolitan area during summer 2012/2013. Rainfall totals were in the 30 mm to 70 mm range, grading to 90 mm in the Perth hills.

The daily rainfall on the 12 December 2012 at Garden Island was their wettest December day in 13 years of record. Please refer to the individual Perth monthly climate summaries for further details.

Perth Metro recorded 28.2 mm of rainfall on 13 rain days during summer 2012/2013, which was near the average of 35.7 mm. Rainfall totals at Perth Metro for the individual months in summer 2012/2013 were: December: 20.2 mm (average 13.3 mm), January: 7.2 mm (average 9.7 mm), and February: 0.8 mm (average 12.7 mm).

Maximum temperature

Day-time temperatures for summer 2012/2013 were very much above average across the Perth metropolitan area, with Perth Metro and Swanbourne are being one of the hottest summer on record. The above average summer was the result of an above average December, a near average January and a very-much-above-average February. Mean daily maxima in the high twenties in islands to low thirties in the coastal plains and hills.

During summer 202/2013, coastal plain sites generally experienced daily maxima temperatures over 35.0 °C one in every three days, whilst hot days with daily maxima over 35 °C across the whole Perth area occurred only on five occasions, notable on 25 December(Christmas Day), 10,12, 20 and 21 February as the result of troughs off the west coast directing northeasterly winds over the city. The highest temperature recorded in the metropolitan area during summer 2013 was 43.2 °C at Pearce RAAF on 21 February. The cool to mild days with daily maxima in twenties across the Perth area were 12 in December, halve in January and down to 3 in February. Bickley recorded the lowest maximum in the metropolitan area on 7 December with 19.7 °C.

Perth Metro's mean daily maximum temperature for summer 2012/2013 was 32.3 °C, which was the hottest summer on record since record commenced in 1897, exceeding the previous record of 32.0°C set on summers of 2010/2011, 2009/2010, and 1977/1978. Daily maxima during summer ranged from a mild 23.6 °C on 7 December to a very hot 42.1°C on 31 December. Perth Metro recorded 21 days with daily maximum temperature of 37 °C or higher, the highest number of such days on record. The previous record was 19 days in summers of 1961/1962 and 1971/1972. The average of 37 °C or higher days was about 10 days.

Minimum temperature

Mean daily minimum temperatures during summer 2012/2013 were above average across the Perth region, with mean daily minima mostly in mid to high teens. The above average summer was the result of an above average December and January, near average February.

During summer 2012/2013,cold nights with daily minima below 10 °C were observed twice in early summer in coastal plains and hills: 1 and 8 December. A daily minimum of 6.2 °C at Perth Airport on 1 December was the lowest overnight temperature of the season. Coastal plain sites generally experienced warm nights with daily minima over 20 °C one in every three days, though warm nights across the whole Perth area were down to 13 occasions: 26 December (Boxing Day), 28 December to 1 January, 6-8 January,15 January, 12-13 February. The warmest summer night saw a minimum of 29.0 °C recorded at Gosnells City on 15 January 2013.

Perth Metro's mean daily minimum temperature for summer 2012/2013 was 18.8 °C, which is above the average of 17.5 °C. Daily minima at Perth Metro in summer ranged from a cool 9.4 °C on 7 December to a hot 27.3 on 29 December 2012 and 15 January 2013.

Wind and Sunshine

Perth’s mean daily sunshine was 11.0 hours per day in summer 2012/2013, which is close to the long term average of 11.3 hours per day.

 

Further information

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Extremes in summer 2012-13
Hottest day 43.2 °C at Pearce RAAF on 21 Feb 2013
43.0 °C at Gosnells City on 31 Dec 2012
42.7 °C at Pearce RAAF on 31 Dec 2012
Warmest days on average 34.3 °C at Pearce RAAF
32.8 °C at Perth Airport
32.3 °C at Perth Metro
Coolest days on average 27.8 °C at Rottnest Island
28.1 °C at Garden Island HSF
30.7 °C at Bickley
Coldest day 19.7 °C at Bickley on 7 Dec 2012
21.1 °C at Rottnest Island on 1 Dec 2012
21.3 °C at Bickley on 6 Dec 2012
Coldest night 6.2 °C at Perth Airport on 1 Dec 2012
6.6 °C at Jandakot Aero on 8 Dec 2012
6.7 °C at Pearce RAAF on 1 Dec 2012
Coolest nights on average 16.1 °C at Bickley
17.5 °C at Jandakot Aero
17.6 °C at Pearce RAAF
Warmest nights on average 19.8 °C at Rottnest Island
19.5 °C at Garden Island HSF
19.1 °C at Champion Lakes
Warmest night 29.0 °C at Gosnells City on 15 Jan 2013
28.6 °C at Pearce RAAF on 12 Feb 2013
28.1 °C at Champion Lakes on 29 Dec 2012
Warmest on average overall 25.9 °C at Pearce RAAF
25.6 °C at Perth Metro
25.5 °C at Champion Lakes
Coolest on average overall 23.4 °C at Bickley
23.8 °C at Garden Island HSF
23.8 °C at Rottnest Island
24.8 °C at Jandakot Aero
Wettest overall 84.6 mm at Champion Lakes
72.1 mm at Medina Research Centre
69.6 mm at Serpentine
Driest overall 27.8 mm at Gosnells City
28.2 mm at Perth Metro
34.0 mm at Perth Airport
Wettest day 50.6 mm at Champion Lakes on 13 Dec 2012
42.8 mm at Serpentine on 12 Dec 2012
38.6 mm at Garden Island HSF on 12 Dec 2012
Highest wind gust 80 km/h at Rottnest Island on 17 Jan 2013
76 km/h at Champion Lakes on 22 Jan 2013
74 km/h at Champion Lakes on 26 Dec 2012
74 km/h at Rottnest Island on 17 Feb 2013
74 km/h at Champion Lakes on 26 Feb 2013

Record highest summer daily rainfall
Highest daily rainfall
in summer 2012-13 (mm)
Previous wettest
for summer
Years of
record
Garden Island HSF 38.6 on 12 Dec 2012 35.4 on 8 Feb 2008 13



Record highest summer mean daily maximum temperature
Mean daily maximum
temperature
for summer 2012-13 (°C)
Previous warmest
for summer
Years of
record
Average for
summer
Rottnest Island 27.8 = 27.8 in 2011 21 26.2
Swanbourne 31.4 = 31.4 in 2010 19 29.3
Perth Metro 32.3 32.0 in 2010,2009,1977 106 30.4



Summary statistics for summer 2012-13
Maximum temperatures
for summer
(°C)
Minimum temperatures
for summer
(°C)
Rainfall
for summer
(millimetres)
Mean for
summer
2012-13
Diff
from
average
Highest for
summer
2012-13
Mean for
summer
2012-13
Diff
from
average
Lowest for
summer
2012-13
Total for
summer
2012-13
Average
for
summer
Rank of
summer
2012-13
Fraction of
summer
average
Bickley 30.7 +0.9 39.0 12 Feb 2013 16.1 +1.2 8.2 1 Dec 2012 54.8 51.0 average 107%
Champion Lakes 32.0   40.8 31 Dec 2012 19.1   9.6 1 Dec 2012 84.6
Garden Island HSF 28.1 +1.1 38.7 21 Feb 2013 19.5 +1.1 13.2 1 Dec 2012 57.4 30.9 high 186%
Jandakot Aero 32.1 +1.5 41.3 12 Feb 2013 17.5 +1.4 6.6 8 Dec 2012 36.8 43.3 average 85%
Medina Research Centre 32.1 +2.0 41.7 12 Feb 2013     9.0 8 Dec 2012 72.1 42.9 high 168%
Pearce RAAF 34.3 +2.0 43.2 21 Feb 2013 17.6 +1.3 6.7 1 Dec 2012 50.0 27.7 high 181%
Perth Airport 32.8 +2.0 42.2 31 Dec 2012 18.0 +1.6 6.2 1 Dec 2012 34.0 35.6 average 96%
Perth Metro 32.3 +1.7 42.1 31 Dec 2012 18.8 +1.2 9.4 8 Dec 2012 28.2 35.7 average 79%
Rottnest Island 27.8 +1.6 38.5 21 Feb 2013 19.8 +1.1 14.4 1 Dec 2012 37.2 29.2 average 127%
Swanbourne 31.4 +2.1 40.9 20 Feb 2013 18.9 +1.2 11.4 8 Dec 2012

Notes

This statement was prepared before all data for the period were available. This may affect some of the statistics presented.

A Seasonal Climate Summary is prepared to list the main features of the weather in Perth 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.

This statement has been prepared based on information available at 2 pm on Wednesday 27 February 2013. Some checks have been made on the data, but it is possible that results will change as new information becomes available.

Averages are long-term means based on observations from all available years of record, which vary widely from site to site. They are not shown for sites with less than 10 years of record, as they cannot then be calculated reliably.
The median is sometimes more representative than the mean of long-term average rain.

The Rank indicates how rainfall this time compares with the climate record for the site, based on the decile ranking (very low rainfall is in decile 1, low in decile 2 or 3, average in decile 4 to 7, high in decile 8 or 9 and very high is in decile 10).
The Fraction of average shows how much rain has fallen this time as a percentage of the long-term mean.

The ACORN-SAT dataset is being used for temperature area averages from December 2012 onwards. The major change from earlier datasets is that the ACORN-SAT dataset commences in 1910, rather than 1950, and hence rankings are calculated using a larger set of years.

Further information

Media
(03) 9669 4057
Enquiries