Monday, 3 March 2014 - Seasonal Climate Summary for Perth - Product code IDCKGC21L0

Perth in summer 2013-14: warm, sunny, and very dry

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

Rainfall

Summer 2013-14 saw well below average rainfall across the Perth metropolitan area as a result of all the summer months recording below average rainfall. Bickley had its driest summer in 43 years of record, whilst Swanbourne had its equal driest summer in 20 years of record, and a number of metropolitan sites had their lowest summer rainfall since at least 2000. Summer rainfall totals were less than 5 mm, with the highest total being 4.6 mm at Werribee, in the hills northeast of Perth.

Perth Metro recorded only 2.0 mm rainfall on two days during summer 2013-14, with 1.8 mm being recorded on 1 December and 0.2 mm on 16 January. This was well below the summer average of 35.4 mm on 8.4 rain days, and Perth Metro's fifth driest summer since records commenced in 1876. It was also Perth Metro's driest summer for four years, since the record dry summer of 2009-2010 when only 0.2 mm was registered. Rainfall totals at Perth Metro for the individual months in summer 2013-14 were: December, 1.8 mm (average 13.3 mm); January, 0.2 mm (average 9.7 mm); and February, 0.0 mm (average 12.6 mm).

Perth Metro experienced 89 consecutive days with daily rainfalls of 0.2 mm or less this summer, from the 2nd December to the end of February, which is the second longest run of days where 0.2 mm or less rainfall has been recorded at Perth Metro since rainfall recordings commenced in 1876. Perth Metro's longest such dry spell is 122 days between 21 November 2009 and 22 March 2010, with the only rainfall recorded during this period being 0.2 mm on 7 February 2010. The dry spell in 2009-10 was broken by the damaging Perth hailstorm of 22 March 2010, with 40.2 mm in the 24 hours to 9am on the 23rd.

Perth Metro's dry spell really commenced on 21 October with only 12.2 mm of rain being recorded on three rain days to the end of February (over the past 131 days), compared to the November to February average of 57.7 mm on 14.4 rain days. The total of three rain days in the November to February period breaks the previous record low for this period of five rain days, recorded in 1902-03, 1997-98, and 2009-10.

Maximum temperature

Daytime temperatures for summer 2013-14 were above average across Perth as a result of consistently above average temperatures in December, January, and February. Mean daily maxima for summer were in the high twenties on the offshore islands, and in the low thirties on much of the coastal plain and in the hills.

During summer 2013-14, the number of hot days with maximum temperatures of 35 °C or higher totalled about 15 in the hills and near the coast, and about 30 in the eastern suburbs. Offshore islands had fewer hot days and Rottnest Island only had one day over 35 °C during the summer. There were three or four hot spells during summer for most sites, including a five-day spell from 12 to 16 December (of note because it was during the Ashes Test), a three-day spell from 10 to12 January (mainly eastern suburbs and hills), the six-day spell from 18 to 23 January, and a six-day spell from 18 to 23 February. The mid-December hot spell also saw a run of four days with maximum temperatures above 40 °C (13th to 16th) at Pearce RAAF, which had not occurred in December at the site in temperature records going back to 1940.

The hottest day in summer in Perth was 11 January, with a maximum temperature of 44.5 °C recorded at Pearce RAAF, whilst a maximum of 44.3 °C at Swanbourne on the 11th was its highest temperature in 19 years of record.

No site recorded a maximum below 20 °C during summer 2013-14.  The lowest maximum temperature for summer 2013-14 in the Perth metropolitan area was 20.3 °C at Garden Island on 3 December.

Perth Metro's mean daily maximum temperature for summer 2013-14 was 32.0 °C , and is the equal second warmest summer for Perth Metro in 116 years of record, equal with the summers of 1977-78, 2009-10, and 2010-11. Perth Metro's warmest summer on record was last year (2012-13), with a mean maximum temperature of 32.3 °C , whilst the last five summers in Perth have been five of the six warmest on record.

Daily maxima at Perth Metro during summer ranged from a mild 23.5 °C on 3 December to a very hot 43.3 °C on 11 January.

Minimum temperature

Mean daily minimum temperatures during summer 2013-14 were near average across the Perth metropolitan area, and were in the mid-to-high teens.

During summer 2013-14, most sites experienced at least 15 to 20 warm nights with daily minima over 20 °C . The warmest night was 12 January, and a minimum of 31.2 °C at Pearce RAAF was not only highest minimum temperature for summer 2013-14 in Perth, but also the highest minimum temperature at Pearce RAAF in 57 years of record. Cold nights were rare and daily minima below 10 °C were recorded at coastal plain and hills sites on 2 to 5 December, 23 December, and 2 January. The lowest temperature recorded during summer in the Perth metropolitan area was 8.4 °C at Medina Research Station on 4 December 2013.

Perth Metro's mean daily minimum temperature for summer 2013-14 was 18.1 °C, near the average of 17.6 °C. Daily minima at Perth Metro ranged from a cold 12.6 °C on 2 January to a record breaking 29.7 °C on 12 January, the highest minimum temperature at Perth Metro since records commenced in 1897. The previous record at Perth Metro was 29.3 °C on 6 February 1898, 8 February 1933, and 3 February 1962.

Sunshine

Perth's mean daily sunshine was 12.2 hours in summer 2013-14, which is the sunniest summer in Perth in 115 years of record, exceeding the previous record of 12.1 hours per day in the summer of 1997-1998.

Further information

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Extremes in summer 2013-14
Hottest day 44.5 °C at Pearce RAAF on 11 Jan 2014
Warmest days on average 34.1 °C at Pearce RAAF
Coolest days on average 27.1 °C at Rottnest Island
30.7 °C at Bickley
Coldest day 20.3 °C at Garden Island HSF on 3 Dec 2013
21.7 °C at Bickley on 1 Dec 2013
Coldest night 8.4 °C at Medina Research Centre on 4 Dec 2013
Coolest nights on average 15.6 °C at Bickley
Warmest nights on average 19.3 °C at Rottnest Island
18.2 °C at Champion Lakes
18.2 °C at Swanbourne
Warmest night 31.2 °C at Pearce RAAF on 12 Jan 2014
Warmest on average overall 25.7 °C at Gosnells City
Coolest on average overall 23.1 °C at Bickley
Wettest overall 4.6 mm at Werribee
Wettest day 4.6 mm at Werribee on 6 Dec 2013
Highest wind gust 81 km/h at Rottnest Island on 7 Feb 2014
81 km/h at Bickley on 26 Feb 2014

Extremes Records Summaries Important notes the top

Record lowest total summer rainfall
Total rainfall
for summer 2013-14 (mm) 		Previous driest
for summer		 Years of
record		 Average for
summer
Bickley 0.8 1.2 in 2009 43 49.9
Swanbourne 0.2 = 0.2 in 2009 20 32.5

Lowest total summer rainfall for at least 10 years
Total rainfall
for summer 2013-14 (mm) 		Most recent summer
at least this dry		 Years since
drier		 Average for
summer
Serpentine 3.6 2.2 in 1974* 19 34.6
Rottnest Island 1.2 0.6 in 1997 16 30.3
Jarrahdale 4.2 =4.2 in 1994* 15 47.4
Gosnells City 2.5 2.0 in 2000 13 38.3
Medina Research Centre 1.4 1.3 in 2000 13 42.5

* note: there are gaps in the historical record at this site, so it is possible a lower value has gone unreported.



Record highest summer temperature
Highest temperature
in summer 2013-14 (°C) 		Previous warmest
for summer		 Years of
record		 Average for
summer
Swanbourne 44.3 on 11 Jan 2014 43.1 on 26 Jan 2012 21 29.4


Record highest summer daily minimum temperature
Highest daily minimum
temperature
in summer 2013-14 (°C)		 Previous warmest
for summer		 Years of
record		 Average for
summer
Perth Metro 29.7 on 12 Jan 2014 29.3 on 6 Feb 1898,8 Feb 1933,3 Feb 1962 116 17.6
Pearce RAAF 31.2 on 12 Jan 2014 30.6 on 31 Jan 1984 57 16.4


Extremes Records Summaries Important notes the top

Summary statistics for summer 2013-14
Maximum temperatures
for summer
(°C)		 Minimum temperatures
for summer
(°C)		 Rainfall
for summer
(millimetres)
Mean for
summer
2013-14		 Diff
from
average		 Highest for
summer
2013-14		 Mean for
summer
2013-14		 Diff
from
average		 Lowest for
summer
2013-14		 Total for
summer
2013-14		 Average
for
summer		 Rank of
summer
2013-14		 Fraction of
summer
average
Bickley 30.7 +0.9 40.7 11 Jan 2014 15.6 +0.6 9.1 4 Dec 2013 0.8 49.9 lowest 2%
Champion Lakes 31.9   42.2 11 Jan 2014 18.2   12.8 4 Dec 2013 0.4
Garden Island HSF 27.6 +0.5 41.4 11 Jan 2014 19.0 +0.5 13.9 4 Dec 2013 2.8 30.7 v low 9%
Gosnells City 33.4 +1.2 44.0 11 Jan 2014 18.1 +0.2 12.0 2 Jan 2014 2.5 38.3 v low 7%
Jandakot Aero 31.8 +1.2 43.2 11 Jan 2014 16.6 +0.5 8.7 2 Jan 2014 2.0 42.0 v low 5%
Medina Research Centre 31.3 +1.1 44.4 11 Jan 2014 16.9 +0.2 8.4 4 Dec 2013 1.4 42.5 v low 3%
Pearce RAAF 34.1 +1.8 44.5 11 Jan 2014 16.9 +0.5 9.3 23 Dec 2013 0.8 27.6 v low 3%
Perth Airport 32.6 +1.7 43.5 11 Jan 2014 17.2 +0.7 9.6 2 Jan 2014 1.0 35.1 v low 3%
Perth Metro 32.0 +1.4 43.3 11 Jan 2014 18.1 +0.5 12.6 2 Jan 2014 2.0 35.4 low 6%
Rottnest Island 27.1 +0.8 35.2 4 Feb 2014 19.3 +0.6 14.0 4 Dec 2013 1.2 28.7 v low 4%
Swanbourne 31.2 +1.8 44.3 11 Jan 2014 18.2 +0.4 12.4 4 Dec 2013 0.2 32.5 lowest 1%

Extremes Records Summaries Important notes the top

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 2 pm on Monday 3 March 2014. 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

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