Perth in autumn 2016: Cool days and warm nights; above average rainfall

Mean maximum temperatures were below average in the Perth metropolitan area, while mean minimum temperatures were above average. Autumn rainfall was above average, particularly at mainland sites.

  • Below average mean maximum temperatures
  • Above average mean minimum temperatures
  • Autumn rainfall was above average for all mainland sites
  • Record highest autumn total rainfall at Mount Helana
  • Record lowest autumn mean maximum temperature at Swanbourne

Rainfall in autumn 2016 was mostly above average in the Perth metropolitan area, with totals ranging from 137.2 mm at Garden Island to 310.0 mm at Bickley. Mount Helana recorded its highest total autumn rainfall on record, with a few other sites recording their highest total autumn rainfall for at least 20 years. Perth Metro recorded a total of 197.0 mm, which was just above the autumn average of 180.2 mm, and the wettest autumn for three years.

Mean maximum temperatures in autumn were 0.4 °C to 1.3 °C below average, with Swanbourne recording its lowest autumn mean daily maximum temperature in its 22 years of record. In contrast, overnight temperatures were between 0.2 °C and 1.0  °C above average. Perth Metro recorded a mean maximum temperature of 25.2 °C, which is the mildest autumn at the site in 19 years, and a mean minimum temperature of 14.4 °C (0.7  °C above average).

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Extremes in autumn 2016
Hottest day 40.9 °C at Medina Research Centre on 14 Mar
40.9 °C at Pearce RAAF on 14 Mar
Warmest days on average 25.7 °C at Gosnells City
Coolest days on average 22.4 °C at Bickley
Coldest day 13.7 °C at Bickley on 21 May
Coldest night 2.1 °C at Jandakot Aero on 8 May
Coolest nights on average 13.0 °C at Bickley
Warmest nights on average 17.2 °C at Rottnest Island
Warmest night 26.9 °C at Pearce RAAF on 14 Mar
Warmest on average overall 20.4 °C at Gosnells City
Coolest on average overall 17.7 °C at Bickley
Wettest overall 310.0 mm at Bickley
Wettest day 55.6 mm at Werribee on 27 Mar
Strongest wind gust 109 km/h at Rottnest Island on 21 May
98 km/h at Perth Airport on 24 May
96 km/h at Garden Island HSF on 21 May
96 km/h at Swanbourne on 21 May
96 km/h at Rottnest Island on 24 May

Record highest autumn total rainfall
New record
(mm)
Old
record
Years of
record
Average for
autumn
Mount Helena 291.9 281.8 in 2005 30 163.3

Highest autumn total rainfall for at least 20 years
Observed
(mm)
Most recent
higher
Average for
autumn
Pearce RAAF 260.2 281.7 in 1974 136.9
Gidgegannup 295.8 368.0 in 1984* 177.8
Maida Vale 224.8 283.0 in 1984* 160.7

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




Record lowest autumn mean daily maximum temperature
New record
(°C)
Old
record
Years of
record
Average for
autumn
Swanbourne 24.3 24.6 in 1997 22 25.6

Lowest autumn mean daily maximum temperature for at least 20 years
Observed
(°C)
Most recent
lower
Average for
autumn
Pearce RAAF 25.6 25.1 in 1992 26.3



Summary statistics for autumn 2016
Maximum temperatures
(°C)
Minimum temperatures
(°C)
Rainfall
(millimetres)
Mean for
autumn
2016
Diff
from
average
Highest for
autumn
2016
Mean for
autumn
2016
Diff
from
average
Lowest for
autumn
2016
Total for
autumn
2016
Average
for
autumn
Rank of
autumn
2016
Fraction of
autumn
average
Bickley 22.4 -1.3 37.2 14 Mar 13.0 +0.5 6.1 30 May 310.0 213.9 high 145%
Garden Island HSF 23.4 -0.8 39.5 14 Mar 16.6 +0.5 9.3 12 May 137.2 134.8 average 102%
Gosnells City 25.7 -0.9 40.3 13 Mar 15.2 +0.6 6.2 12 May 209.0 166.9 high 125%
Jandakot Aero 25.0 -0.8 40.7 14 Mar 13.3 +0.9 2.1 8 May 217.8 167.4 high 130%
Medina Research Centre     40.9 14 Mar 13.7 +0.4 3.5 8 May 191.4 161.0 high 119%
Pearce RAAF 25.6 -0.7 40.9 14 Mar 13.6 +0.2 2.6 8 May 260.2 136.9 v high 190%
Perth Airport 25.3 -0.4 40.1 14 Mar 13.8 +0.7 3.1 8 May 180.4 156.6 high 115%
Perth Metro 25.2 -0.7 39.8 14 Mar 14.4 +0.7 4.6 8 May 197.0 180.2 high 109%
Rottnest Island 23.3 -0.4 39.4 14 Mar 17.2 +0.1 10.5 22 May 139.6 129.6 average 108%
Swanbourne 24.3 -1.3 40.7 14 Mar 15.6 +0.6 8.1 31 May 229.0 156.4 high 146%
Note: Observations for “Perth Metro” are taken from the current site at Mount Lawley (Bureau number 009225).
Comparisons are made against combined data from the current site (which opened in early 1993) and the previous site at Perth Regional Office (009034), which ran from 1876 to early 1992.

Notes

The Seasonal climate summary lists 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.

A climate summary is generally published on the first working day of each month.

This statement has been prepared based on information available at 12 pm on Wednesday 1 June 2016. Some checks have been made on the data, but it is possible that results will change as new information becomes available.

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.

Observations for “Perth Metro” are taken from the current site at Mount Lawley (Bureau number 009225).
Comparisons are made against combined data from the current site (which opened in early 1993) and the previous site at Perth Regional Office (009034), which ran from 1876 to early 1992.

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 used for temperature area averages.

Further information

Media
(03) 9669 4057
Enquiries