Greater Perth in September 2019: Dry with warm days

Rainfall in September 2019 was below average across Greater Perth, and it was driest September on record at Perth Metro. Mean maximum temperatures were well above average and mean minimum temperatures were generally near average to above average.

Dry across Greater Perth

  • Monthly rainfall totals were generally in the 20-40 mm range, up to 60-80 mm in the Perth hills, recorded over 5 or 6 days
  • Cold fronts produced moderate rainfall for many sites across Greater Perth on the 2nd, 3rd and 18th; Karnet recorded the highest daily rainfall with 30 mm on the 3rd, and Mount Solus had the highest monthly total with 85.6 mm
  • Perth Metro recorded a monthly rainfall of 31.4 mm, which was its driest September on record; previous September record was 35.2 mm in 2018 and 2004
  • Mundaring and Maida Vale in the Perth hills had their driest September since 1977
  • Perth Metro's year-to-date rainfall was 541.8 mm, which was over 100 mm below its nine-months average rainfall, and driest year-to-date since 2012 (514.2 mm)

Warm days across Greater Perth

  • Mean maximum temperatures were one to two degree above average; mean minimum temperatures were mostly near average to above average
  • Perth Metro's mean maximum temperature was 22.9 °C , which was its warmest September on record
  • Perth Airport and several other sites also had their warmest September on record in terms of maximum temperatures
  • Perth Metro's 33.1 °C on the 9th was its second-highest September temperature on record, and the earliest spring season with temperature over 33 °C; Perth Metro's September temperature record (34.2 °C on 20 September 2014) is the previous such earliest season record holder
  • Perth Metro's year-to-date mean maximum temperature was 24.7 °C, 0.5 °C above average and the warmest since 2015 (24.8 °C)
  • Perth Metro's year-to-date mean minimum temperature was 12.1 °C, 0.3 °C below average and the coolest since 2010 (11.7 °C)

Perth Metro

  • Total rainfall for Perth Metro was 31.4 mm, which is 38% of the long-term average of 82.8 mm and the driest on record
  • The mean daily maximum temperature for Perth Metro was 22.9 °C, which is 2.6 °C above the long-term average of 20.3 °C. The warmest day was 33.1 °C on the 9th, and the coolest day was on the 19th when the temperature reached 15.6 °C
  • The mean daily minimum temperature for Perth Metro was 9.6 °C, which is 0.1 °C above the long-term average of 9.5 °C. The coldest morning was 2.5 °C on the 7th, and the warmest morning was on the 30th when the minimum temperature was 14.9 °C

Further information

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Extremes in September 2019
Hottest day 33.1 °C at Perth Metro on the 9th
Warmest days on average 23.2 °C at Millendon (Swan Valley)
Coolest days on average 19.9 °C at Garden Island HSF
Coldest day 12.4 °C at Bickley on the 19th
Coldest night 0.2 °C at Karnet on the 5th
Coolest nights on average 7.4 °C at Karnet
Warmest nights on average 13.8 °C at Rottnest Island
Warmest night 17.8 °C at Garden Island HSF on the 11th
Warmest on average overall 16.9 °C at Rottnest Island
Coolest on average overall 14.7 °C at Bickley
Wettest overall 85.6 mm at Mount Solus
Driest overall 17.6 mm at Mosman Park
Wettest day 30.0 mm at Karnet on the 3rd
Strongest wind gust 91 km/h at Perth Airport on the 1st

Record lowest September total rainfall
New record
(mm)
Old
record
Years of
record
Average for
September
Mosman Park 17.6 20.5 in 1977 39 68.7
Perth Metro 31.4 35.2 in 2018 27 82.8
Swanbourne 18.0 30.4 in 2000 26 79.0

Lowest September total rainfall for at least 20 years
Observed
(mm)
Most recent
lower
Average for
September
Mundaring 45.8 42.2 in 1977* 111.6
Maida Vale 39.8 28.2 in 1977* 85.9
Araluen 39.6 38.6 in 1974* 107.7

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




Record highest September mean daily maximum temperature
New record
(°C)
Old
record
Years of
record
Average for
September
Perth Airport 23.1 22.8 in 2015 75 20.2
Pearce RAAF 23.0 22.7 in 2015 58 20.1
Jandakot Aero 22.4 22.2 in 2015 29 20.1
Gosnells City 23.0 22.9 in 2014 26 20.8
Bickley 20.2 19.8 in 2015 25 17.5
Perth Metro 22.9 22.5 in 2015 25 20.3



Record highest September mean temperature
New record
(°C)
Old
record
Years of
record
Average for
September
Bickley 14.7 14.3 in 2014 25 12.9



Summary statistics for September 2019
Maximum temperatures
(°C)
Minimum temperatures
(°C)
Rainfall
(millimetres)
Mean for
September
2019
Diff
from
average
Highest for
September
2019
Mean for
September
2019
Diff
from
average
Lowest for
September
2019
Total for
September
2019
Average
for
September
Rank of
September
2019
Fraction of
September
average
Bickley 20.2 +2.7 29.4 9th 9.2 +1.0 2.4 5th 67.0 123.2 low 54%
Garden Island HSF 19.9 +1.1 28.9 9th 12.4 +0.5 7.5 5th 23.0 62.7 v low 37%
Gosnells City 23.0 +2.2 33.0 9th 10.2 +0.2 4.0 7th 11.6 79.8 v low 15%
Jandakot Aero 22.4 +2.3 32.2 9th 8.2 0.0 1.4 7th 31.2 84.2 v low 37%
Karnet 19.7 +2.1 29.4 9th 7.4 +0.2 0.2 5th 82.9 131.6 low 63%
Mandurah 20.3 +1.3 26.8 9th 12.3 +0.6 5.4 5th 22.8 61.8 low 37%
Millendon (Swan Valley) 23.2   31.4 9th 8.5   2.1 7th 34.2
Pearce RAAF 23.0 +2.9 31.5 9th 9.1 +0.3 1.5 20th 29.6 68.2 v low 43%
Perth Airport 23.1 +2.9 32.6 9th 9.0 +0.1 1.7 7th 31.4 72.2 low 43%
Perth Metro 22.9 +2.6 33.1 9th 9.6 +0.1 2.5 7th 31.4 82.8 lowest 38%
Rottnest Island 20.0 +1.2 27.1 9th 13.8 +0.9 9.0 5th 17.8 53.2 v low 33%
Swanbourne 21.2 +1.3 32.9 9th 11.7 +0.7 5.3 5th 18.0 79.0 lowest 23%

Daily maximum temperatures for September 2019
123456789101112131415161718192021222324252627282930
Bickley14.815.914.413.313.817.319.723.529.427.521.623.625.222.221.423.320.317.812.414.916.217.622.625.820.018.721.522.327.921.5
Garden Island HSF18.519.217.515.616.019.118.018.628.922.222.422.121.822.118.524.621.721.214.615.916.418.924.019.819.417.519.121.021.4
Gosnells City19.020.518.016.517.520.821.626.533.029.524.026.027.525.623.527.023.121.016.018.919.526.528.521.123.224.1
Jandakot Aero18.319.917.916.716.819.721.124.332.227.123.224.726.324.321.826.322.921.115.317.518.920.125.627.021.522.122.022.530.523.2
Karnet15.016.815.013.314.517.417.923.229.427.620.322.624.521.821.021.720.017.415.814.915.918.923.025.018.118.421.4
Mandurah18.418.417.316.217.117.319.622.526.821.721.922.122.322.220.323.221.019.614.717.018.020.323.522.419.620.919.521.124.720.6
Millendon (Swan Valley)18.820.117.916.316.420.221.726.031.429.124.226.528.124.824.126.023.921.815.918.319.520.525.828.423.922.424.024.830.924.6
Pearce RAAF18.520.618.217.116.419.621.326.231.529.223.926.227.924.523.126.123.021.715.417.619.020.226.028.423.521.723.424.030.823.6
Perth Airport19.120.218.316.816.720.422.025.832.629.223.425.827.224.523.426.322.721.316.018.519.420.726.029.123.322.823.123.730.824.0
Perth Metro19.120.218.217.416.920.220.825.133.128.023.525.326.724.321.726.622.621.815.618.018.820.626.528.423.222.822.123.431.024.0
Rottnest Island18.319.717.716.514.319.218.020.227.122.421.922.022.222.519.023.321.320.815.116.216.417.724.722.721.519.918.219.022.121.4
Swanbourne18.419.318.416.516.920.418.922.832.922.622.122.422.119.626.222.321.414.616.917.220.125.024.621.021.020.021.126.722.1
Values are the maximum temperature, usually in the 24 hours from 9 am on the day indicated,
and typically occurred in the afternoon of that day.
Temperatures coloured according to their difference
from the long-term average for the period
-10.0 -9.0 -8.0 -7.0 -6.0 -5.0 -4.0 -3.0 -2.0 -1.0 0.0 +1.0 +2.0 +3.0 +4.0 +5.0 +6.0 +7.0 +8.0 +9.0 +10.0 °C Grey outline marks highest
and lowest for the period

Daily minimum temperatures for September 2019
123456789101112131415161718192021222324252627282930
Bickley10.08.58.58.32.42.75.27.611.312.713.412.512.413.310.59.913.311.46.44.04.95.36.111.211.59.89.79.011.113.6
Garden Island HSF15.015.113.912.47.57.68.211.19.013.717.813.611.814.314.114.014.416.810.28.19.99.411.011.113.413.612.113.413.417.4
Gosnells City12.99.510.511.04.55.04.05.412.111.014.012.012.514.912.014.012.513.010.05.05.47.112.012.011.5
Jandakot Aero11.29.110.811.31.53.31.46.57.38.411.59.010.213.011.012.58.610.49.81.64.54.56.28.27.09.78.38.49.811.2
Karnet8.67.97.98.10.22.52.47.18.18.413.29.69.512.08.310.49.110.86.51.04.44.06.78.77.36.39.010.0
Mandurah15.015.312.512.25.47.18.09.911.213.117.415.114.616.113.713.514.315.59.75.99.18.59.813.614.212.711.612.914.116.4
Millendon (Swan Valley)10.59.211.38.03.62.82.15.38.27.013.19.810.411.410.912.011.410.89.62.36.06.56.912.27.110.36.69.49.312.3
Pearce RAAF9.910.112.39.35.42.72.74.410.08.012.89.811.011.610.812.913.411.99.51.56.28.27.412.97.610.67.79.78.713.7
Perth Airport10.98.910.610.32.63.01.76.28.910.012.911.811.312.010.612.911.911.59.52.05.56.27.414.07.110.27.69.810.612.8
Perth Metro11.79.412.211.53.24.12.56.88.310.513.311.512.214.911.313.312.010.69.93.05.65.38.410.09.811.39.610.411.914.9
Rottnest Island15.214.013.511.59.09.912.112.014.714.217.216.316.417.115.314.716.515.810.410.610.210.312.516.015.615.112.713.815.116.8
Swanbourne12.714.913.512.05.35.86.09.111.813.115.913.714.315.812.913.814.515.710.46.56.77.49.413.510.713.111.910.612.316.2
Values are the minimum temperature, usually in the 24 hours to 9 am on the day indicated,
and typically occurred that morning.
Temperatures coloured according to their difference
from the long-term average for the period
-10.0 -9.0 -8.0 -7.0 -6.0 -5.0 -4.0 -3.0 -2.0 -1.0 0.0 +1.0 +2.0 +3.0 +4.0 +5.0 +6.0 +7.0 +8.0 +9.0 +10.0 °C Grey outline marks highest
and lowest for the period

Daily rainfall for September 2019
123456789101112131415161718192021222324252627282930
Anketell 2.2 10.2 17.8 1.2 - - - - - - - - - - - - - 0.4 9.2 0.6 - - - - - 1.6 - - - -
Araluen 17.0 - 2.7 - 0.4 - - - - - - - - - - - - 19.4 - - - - - - 0.1




Bickley 0.8 28.2 12.6 3.6 - - - - - - - - 0.2 - - - - 0.2 21.4 - - - - - - - - - - -
Bungendore 0.4 18.0 16.4 1.6 0.2 - 0.2 - 0.2 - - - 0.2 - 0.2 - - 0.2 15.4 0.2 0.2 - - - - 1.4 0.2 - 0.2 -
Chidlow 15.1



























Garden Island HSF - 7.6 7.8 1.4 - - - - - - - - - 0.2 - - - - 4.8 0.6 - - - -
0.6 - - - -
Gidgegannup 0.4 14.2 6.2 1.8 - - - 0.2 - - - - - 0.2 - - - - 21.4 0.4 - - - - - - - 0.2 - -
Gosnells City 0.4 - - - - - - - - - - - - - - - - - 11.2 - - - - - - - - - -
Huntly 0.6 18.0 14.3 4.8 0.2 - - - - - - - - 0.3 - - - 2.2 22.0 - - - - - 1.0 0.5 - - - -
Jandakot Aero 0.2 8.2 9.0 2.8 - - - - - - - - - - - - - 0.2 10.6 0.2 - - - - - - - - - -
Jarrahdale 2.2 11.6 12.8 4.6 0.4 - 0.2 0.2 0.2 0.4 - - 0.4 - 0.2 - - 0.6 21.4 0.2 0.4 - 0.2 0.2 - 0.6 - 0.2 0.2 0.2
Karnet 11.7 11.6 30.0 0.6 - - - - - - - - - - - - - 1.6 25.5 0.3 - - - - - 1.6 - -

Karragullen North 1.2 13.4 10.4 4.4 - - - - - - - - - - - - - - 22.8










Maida Vale 0.2 18.6 5.2 3.2 - - - - - - - - - - - - - - 12.6










Mandurah 0.2 2.8 4.0 3.6 - - - - - - - - - 0.6 - - - 0.6 6.8 0.4 - - - - 1.8 2.0 - - - -
Midland 22.8 - - - - - - - - - - - - - - - - - 10.5









Millendon (Swan Valley) - 10.8 5.4 2.0 0.2 - - - - - - - - - - - - - 15.4 0.4 - -
- - - - - - -
Mosman Park - 7.0 2.2 1.6 0.2 - - - - - - - - - - - - - 6.6










Mount Solus 1.6 17.4 29.8 6.4 - 0.2 - - - - - - 0.2 - - - - 0.8 27.2 0.2 - 0.2 - - - 1.6 - - - -
Muchea - 13.6 8.4 1.8 - - - 0.2 - - - 0.2 - - - - - - 8.0 0.6 0.2 - - - - - - - 0.2 -
Mundaring 0.6 15.8 11.2 1.6 0.2 - - - - - - - - - - - - - 16.2 0.2 - - - - - - - - - -
Pearce RAAF - 9.2 10.2 3.2 0.2 - - - - - - - - - - - - - 6.6 0.2 - - - - - - - - - -
Perth Airport - 17.6 2.4 1.4 - - - - - - - - - - - - - - 9.8 0.2 - - - - - - - - - -
Perth Metro 0.2 13.8 3.6 1.4 - - - - - - - - - - - - - - 11.4 1.0 - - - - - - - - - -
Pinjarra Refinery 1.6 6.4 9.4 3.0 0.1 - - - - - - - - 0.2 - - - 0.6 10.0 0.2 - - - - 0.3 0.6 - - - -
Pinjarra South 0.2 4.8 14.6 1.8 - - - - - - - - - - - - - 0.4 5.0 - - - - - 0.4 0.2 - - - -
Roleystone - 15.0 11.4 3.8 - - - - - - - - - - - - - - 18.8 0.2 - - - - - - - - - -
Rottnest Island 1.2 7.0 3.2 1.4 - - - - - - - 0.2 - - - - - - 4.4 0.4 - - - - - - - - - -
Serpentine 1.4 9.0 16.0 3.8 0.2 - - - - - - - - - - - - 0.4 11.0 - - - - - - 1.6 - - - -
Subiaco Treatment Plant 1.0 7.0 2.2 2.4 - - - - - - -


















Swanbourne 0.4 6.6 2.2 1.6 0.2 - - - - - -
0.2 0.2 - - - - 6.2
- - - - 0.2 0.2 - - - -
Tamala Park (Mindarie) - 10.4 2.4 1.3 0.1 - - - - - - - - - - - - - 6.2 0.4 - - - - - - - - - 0.5
Wanneroo 18.6 5.6 1.6 - - - - - - - - - - - - 11.6 0.4









Werribee - 15.4 6.6 2.4 0.2 0.2 - - 0.2 - - - - 0.2 - - - - 11.6 - - 0.2 - - - - - 0.2 - -
Whiteman Park - 9.0 8.0 3.2 - - - - - - - - - - - - - - 12.8 0.8









Most values are the precipitation in the 24 hours to 9 am on the day indicated. Days marked with → are part of a longer accumulation, which is shown on the final day.
Values over 100 mm have been rounded to the nearest whole millimetre.
Days marked with - have a rainfall report of zero; days left blank have no rainfall report (which often indicates no rain fell).
Rainfalls coloured
according to the amount
0 1.0 5.0 10.0 15.0 25.0 50.0 100 150 200 300 400 600 millimetres

Notes

The Monthly 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 10 am on Tuesday 1 October 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