Greater Perth in spring 2019: very warm and dry

Spring 2019 was very warm and dry across Greater Perth. Rainfall totals were well below seasonal averages due to a very dry start to spring with Perth Metro recording its driest September on record. Mean maximum temperatures were more than one degree above average, and it was Perth city's equal second-warmest spring on record.

Well below average rainfall

  • Spring rainfall totals were about 50-80 mm for coastal plain locations and offshore islands, up to 150-170 mm in the Perth hills; spring rainfall for all locations across Greater Perth was about 40% to 70% of their respective seasonal rainfall average
  • Perth Metro's spring rainfall is estimated at 77.6 mm (*), which was its second-lowest spring rainfall in 26 years of records, and lowest for nine years when 75.8 mm was recorded in spring 2010
  • Swanbourne recorded 60.8 mm this spring, which was their driest spring on record

Very warm daytime temperatures

  • Mean maximum temperatures were 1-3 °C above average and mean minimum temperatures were slightly above average across Greater Perth
  • Perth Metro recorded a mean maximum temperature of 25.3 °C, which was its equal second-warmest spring in 26 years of record, equalling with 2010 and behind the record warm spring in 2015 (25.9 °C)
  • It was only the third occasion that spring mean maximum temperature reached 25 °C in Perth city since temperature records commenced in 1897
  • Coastal plain locations experienced four consecutive days with 35 °C or higher in late spring between 13 and 16 November, which was the first such hot spell for Perth Metro and Perth Airport; the Perth city previously had only one such hot spell when temperatures exceeded 35 °C between 9 and 12 November in 1933 at Perth Regional Office
  • The hottest spring days were on 9 or 16 November, with temperatures reached the high 30s to the low 40s; Perth Metro, Perth Airport and several others sites had their highest spring temperature on record

Perth Metro

  • (*) Perth Metro's spring rainfall was estimated at 77.6 mm, due to the rain gauge blockage daily rainfall was estimated at 10 mm on 5 October
  • The mean daily maximum temperature for Perth Metro was 25.3 °C, which is 1.8 °C above the long-term average of 23.5 °C. The warmest day was 40.4 °C on 16 Nov, and the coolest day was on 19 Sep when the temperature reached 15.6 °C
  • The mean daily minimum temperature for Perth Metro was 12.2 °C, which is 0.4 °C above the long-term average of 11.8 °C. The coldest morning was 2.5 °C on 7 Sep, and the warmest morning was on 9 Nov when the minimum temperature was 19.9 °C

Further information

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Extremes in spring 2019
Hottest day 43.1 °C at Pearce RAAF on 16 Nov
Warmest days on average 26.6 °C at Pearce RAAF
Coolest days on average 21.9 °C at Rottnest Island
Coldest day 12.4 °C at Bickley on 19 Sep
Coldest night 0.2 °C at Karnet on 5 Sep
Coolest nights on average 10.6 °C at Bickley
Warmest nights on average 15.0 °C at Rottnest Island
Warmest night 22.3 °C at Pearce RAAF on 14 Nov
Warmest on average overall 18.9 °C at Pearce RAAF
Coolest on average overall 16.8 °C at Bickley
Wettest overall 185.4 mm at Karnet
Driest overall 47.0 mm at Rottnest Island
Wettest day 34.4 mm at Karnet on 3 Sep
Strongest wind gust 107 km/h at Rottnest Island on 4 Oct

Record lowest spring total rainfall
New record
(mm)
Old
record
Years of
record
Average for
spring
Swanbourne 60.8 68.8 in 2000 26 143.9



Record highest spring temperature
New record
(°C)
Old
record
Years of
record
Average for
spring
Perth Airport 41.1 on 16 Nov 40.8 on 11 Nov 2003 76 23.0
Pearce RAAF 43.1 on 16 Nov 41.6 on 22 Nov 1978 65 23.6
Jandakot Aero 40.3 on 9 Nov 40.0 on 11 Nov 2003 30 23.1
Gosnells City 41.5 on 16 Nov 41.4 on 11 Nov 2003 27 24.3
Bickley 38.9 on 16 Nov 38.0 on 11 Nov 2003 26 21.2
Perth Metro 40.4 on 16 Nov 40.3 on 11 Nov 2003 26 23.5



Summary statistics for spring 2019
Maximum temperatures
(°C)
Minimum temperatures
(°C)
Rainfall
(millimetres)
Mean for
spring
2019
Diff
from
average
Highest for
spring
2019
Mean for
spring
2019
Diff
from
average
Lowest for
spring
2019
Total for
spring
2019
Average
for
spring
Rank of
spring
2019
Fraction of
spring
average
Bickley 23.1 +1.9 38.9 16 Nov 10.6 +0.7 2.4 5 Sep 155.0 228.7 low 68%
Garden Island HSF 22.1 +0.9 38.1 9 Nov 14.2 +0.4 7.5 5 Sep 55.6 110.0 low 51%
Jandakot Aero 25.1 +2.0 40.3 9 Nov 10.7 +0.5 1.4 7 Sep 84.0 159.1 v low 53%
Mandurah 23.1 +1.2 37.7 15 Nov 13.9 +0.3 5.4 5 Sep 62.6 115.8 low 54%
Millendon (Swan Valley) 26.2   42.2 16 Nov 10.8   2.1 7 Sep 83.0
Pearce RAAF 26.6 +3.0 43.1 16 Nov 11.1 +0.6 1.5 20 Sep 62.0 125.8 v low 49%
Perth Airport 25.9 +2.9 41.1 16 Nov 11.2 +0.5 1.7 7 Sep 76.6 140.7 v low 54%
Perth Metro 25.3 +1.8 40.4 16 Nov 12.2 +0.4 2.5 7 Sep
Rottnest Island 21.9 +1.1 35.8 9 Nov 15.0 +0.7 9.0 5 Sep 47.0 99.5 v low 47%
Swanbourne 23.5 +1.0 40.0 9 Nov 13.5 +0.8 5.3 5 Sep 60.8 143.9 lowest 42%

Notes

The Seasonal climate summary, generally published on the first working day of each month, lists the main features of the weather in Greater Perth using the most timely and accurate information available on the date of publication; it will generally not be updated. More extensive discussion of significant weather events, along with later information and data that has had greater opportunity for quality control, will be presented in the Monthly Weather Review.

This summary includes data from observing sites in or near the Greater Perth “Greater Capital City Statistical Area” (GCCSA). The Australian Bureau of Statistics designed the GCCSAs to “include the population within the urban area of the city, as well as people who regularly socialise, shop or work within the city, and live in small towns and rural areas surrounding the city. It is important to note that GCCSAs do not define the built up edge of the city. They provide a stable definition for these cities and are designed for the output of a range of social and economic survey data.

This statement has been prepared based on information available at 9 am on Monday 2 December 2019. Some checks have been made on the data, but it is possible that results will change as new information becomes available.

In some situations, some or all of the rainfall is in the form of hail or snow. In these cases the totals given are for the water equivalent: the depth of liquid water that results from melting any frozen precipitation. There can be significant 'undercatch' of snow in strong winds, meaning the true precipitation can be higher than that reported.

Averages for individual sites 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.

Where temperature area averages are mentioned, they are derived from the ACORN-SAT dataset.

Further information

Media
(03) 9669 4057
Enquiries