Perth in winter 2013: a dry winter

  • Rainfall: below average
  • Maximum temperature: near average to above average
  • Minimum temperature: near average

Rainfall

Winter 2013 saw below average rainfall in the Perth metropolitan area as the result of a record dry June, a near average July, and an above average August. Winter rainfall totals were generally in the 230 mm to 290 mm range on the offshore islands, 290 mm to 400 mm on the coastal plain, and near 530 mm in the hills.

Significant rainfall events during winter 2013 in Perth:

  • generally only light to moderate falls in June with a number of sites reporting their driest June on record
  • a strong cold front moved through the metropolitan area in the afternoon on 9 July bringing moderate to heavy falls
  • two cold fronts moved across the region on 15 and 16 July with most sites receiving moderate rainfall
  • a series of cold fronts and associated cloudbands brought moderate to heavy falls to most sites on 24, 26, and 27 July
  • a slow moving cloudband ahead of an approaching cold front brought persistent showery periods, with moderate to heavy falls between 5 and 8 August. Bickley recorded a daily total of 80.2 mm on 8 August, the highest daily fall in the Perth metropolitan area in winter 2013
  • a low pressure system on 27 and 28 August brought moderate to heavy falls

Perth Metro recorded 351.4 mm of rainfall on 43 rain days during winter 2013, which was well below the average of 477.2 mm on 47.7 rain days. Rainfall totals at Perth Metro for the individual months in winter 2013 were: June: 44.0 mm (average 175.4mm), July: 140.0 mm (average 168.7 mm), and August: 167.4 mm (average 133.1 mm).

Maximum temperature

Daytime temperatures for winter 2013 were near average to above average as a result of a near average June and July, and an above average August. Mean daily maxima for winter were in the mid-teens in the hills and high teens on the coastal plain and offshore islands. Rottnest Island, Swanbourne, and Pearce RAAF all recorded their equal warmest winter on record.

During winter 2013, sites on the Swan coastal plain experienced approximately 30 days with daily maximum temperatures in the low twenties, and only one day with temperatures consistently at or below 15 ºC. On that day, 17 July, Bickley recorded a maximum of 11.6 ºC, the lowest maximum temperature in the metropolitan area in winter 2013. The warmest day for most sites occurred on 24 August and the highest temperature recorded in the metropolitan area in winter 2013 was 26.9 °C at Gosnells City on that day.

Perth Metro's mean daily maximum temperature for winter 2013 was 19.7 °C, which was the equal second warmest winter on record, equal with the winters of 1976, 1983, and 2012. Perth Metro's warmest winter was in 2006 with a mean maximum temperature of 19.8 °C. Daily maxima at Perth Metro during winter ranged from a cold 14.6 °C on 17 July to a warm 26.4 °C on 24 August.

Minimum temperature

Mean daily minimum temperatures during winter 2013 were near average for most sites to below average in the northeast suburbs, with mean daily minima generally in the 8 ºC to 9 ºC range in the hills and on the inland coastal plain, about 10 ºC near the coast, and in the 12 ºC to 13 °C range on the offshore islands. The winter mean minimum temperatures were the result of a near average to below average June, a near average to below average July, and a very much above average August. Rottnest Island recorded mean minima slightly above the average in June and July, and a very much above average August, resulting in it recording its equal highest winter mean maximum in 115 years of record.

During winter 2013, most sites experienced three mild nights with daily minima over 15 °C from 6 to 8 August, with Jandakot Aerodrome and Swanbourne recording their equal highest winter minima on 7 August, whilst Perth Metro recorded its mildest winter night in 116 years of recording. However, the highest overnight temperature recorded in the Perth metropolitan area in winter 2013 was on 9 June when Rottnest Island recorded a minimum of 17.7 °C . Most sites on the coastal plain and in the hills experienced four very cold nights with daily minima below 5 °C on 8, 18, 20, and 21 July, with the lowest temperature in winter 2013 in the Perth area being -1.2 °C at Jandakot Aerodrome on 8 July.

Perth Metro's mean daily minimum temperature for winter 2013 was 8.5 °C, which is near the average of 8.1 °C. Daily minima at Perth Metro ranged from a very cold 1.4 °C on 18 July to a record mild 17.1 °C on 7 August.

Wind and Sunshine

Perth’s mean daily sunshine was 6.8 hours in winter 2013, which is close to the long term average of 6.4 hours per day. It was the sunniest winter for three years since a mean of 7.2 hours was recorded in winter 2010.

Further information

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Extremes in winter 2013
Hottest day 26.9 °C at Gosnells City on 24 Aug
Warmest days on average 19.7 °C at Pearce RAAF
19.7 °C at Perth Metro
19.7 °C at Swanbourne
Coolest days on average 16.3 °C at Bickley
Coldest day 11.6 °C at Bickley on 17 Jul
Coldest night -1.2 °C at Jandakot Aero on 8 Jul
Coolest nights on average 7.4 °C at Jandakot Aero
Warmest nights on average 13.4 °C at Rottnest Island
Warmest night 17.7 °C at Rottnest Island on 9 Jun
17.3 °C at Swanbourne on 7 Aug
Wettest overall 527.8 mm at Bickley
Wettest day 80.2 mm at Bickley on 8 Aug
Highest wind gust 111 km/h at Rottnest Island on 16 Jul
98 km/h at Bickley on 26 Jul

Record highest winter mean daily maximum temperature
Mean daily maximum
temperature
for winter 2013 (°C)
Previous warmest
for winter
Years of
record
Average for
winter
Pearce RAAF 19.7 = 19.7 in 2006 52 18.3
Rottnest Island 18.9 = 18.9 in 2006 115 18.1
Swanbourne 19.7 = 19.7 in 2012 19 18.8



Record highest winter daily minimum temperature
Highest daily minimum
temperature
in winter 2013 (°C)
Previous warmest
for winter
Years of
record
Average for
winter
Jandakot Aero 16.5 on 7 Aug = 16.5 on 7 Aug 2006 24 7.0
Perth Metro 17.1 on 7 Aug 17.0 on 7 Aug 2006 116 8.1
Swanbourne 17.3 on 7 Aug = 17.3 on 7 Aug 2006 20 10.0



Record highest winter mean daily minimum temperature
Mean daily minimum
temperature
for winter 2013 (°C)
Previous warmest
for winter
Years of
record
Average for
winter
Rottnest Island 13.4 =13.4 in 1994 115 12.6



Summary statistics for winter 2013
Maximum temperatures
for winter
(°C)
Minimum temperatures
for winter
(°C)
Rainfall
for winter
(millimetres)
Mean for
winter
2013
Diff
from
average
Highest for
winter
2013
Mean for
winter
2013
Diff
from
average
Lowest for
winter
2013
Total for
winter
2013
Average
for
winter
Rank of
winter
2013
Fraction of
winter
average
Bickley 16.3 +0.6 23.1 24 Aug 8.2 +0.6 1.7 8 Jul 527.8 591.3 average 89%
Champion Lakes 18.7   24.4 24 Aug 9.6   3.7 18 Jul 354.4
Garden Island HSF 18.7 +0.4 21.9 23 Aug 12.0 +0.6 6.5 8 Jul 293.8 321.8 low 91%
Jandakot Aero 19.2 +0.7 25.0 24 Aug 7.4 +0.4 -1.2 8 Jul 411.0 459.9 average 89%
Medina Research Centre         8.4 -0.1 0.8 18 Jul        
Pearce RAAF 19.7 +1.4 26.2 24 Aug 7.6 -1.1 -0.9 18 Jul 264.7 372.7 low 71%
Perth Airport 19.6 +1.2 26.1 24 Aug 8.1 -0.2 -0.3 18 Jul 293.2 434.6 v low 67%
Perth Metro 19.7 +0.8 26.4 24 Aug 8.5 +0.4 1.4 18 Jul 351.4 477.2 low 74%
Rottnest Island 18.9 +0.8 22.9 23 Aug 13.4 +0.8 9.2 17 Jul 229.2 391.1 low 57%
Swanbourne 19.7 +0.9 23.7 24 Aug 10.3 +0.3 4.4 8 Jul 368.4 388.8 average 95%

Notes

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 10 am on Monday 2 September 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