Perth in August 2014: Record warm month

Rainfall was near average for most sites in August 2014, with a very dry start to the month and a wet second half. Monthly rainfall totals ranged from about 60 to 80 mm on the offshore islands, to between 100 and 120 mm on the coastal plain, to over 150 mm in the hills. Rain days were mostly below average with only 10 to 11 rain days recorded for the month at some sites.

Across the Perth metropolitan area, mean daily maximum temperatures were generally 2 to 3 °C above the long-term average, and all sites broke their previous record for the highest mean maximum temperature in August. With the exception of the start and end of the month, most days in August were mild with daily maxima commonly above 20 °C on the coastal plain. The coolest day was the 1st or 31st for most sites, in terms of daytime temperatures, and the warmest days were the 6th and 17th with daily maxima in the mid-twenties. Mean minimum temperatures were generally 1 to 2 °C above average across the Perth region, and Rottnest Island recorded its equal warmest August since records commenced in 1880, whilst a number of sites had their warmest August nights since 1998. Very cold nights with minima below 5 °C were seen mainly at the start of the month for coastal plain sites, whilst cool nights with minima in the low teens were common throughout the rest of August.

  • A strong cold front and a cut off low produced thunderstorms and squally winds in the Perth area on the evening the 17th. Severe wind gusts to 104 km/h were recorded at Rottnest Island. In Fremantle, a container ship broke its moorings during the storm (around 10 pm WST) and crashed into the Fremantle rail bridge closing the rail line for inspection and repairs. A second cargo vessel also broke its moorings and hit a refuelling vessel, which was docked near the bridge.
  • A rainband and associated cold front produced heavy rainfall across the Perth area on the 29th and 30th. Mundaring recorded a daily total of 70.8 mm on the 30th, the highest daily rainfall of the month in the Perth area, and the second wettest August day at Mundaring in 104 years of record.
  • Perth Metro recorded a mean maximum temperature of 21.6 °C, the warmest August in 117 years of record and exceeding the previous record by 1.2 °C, which was set in August 2013.
  • Perth Metro recorded 21 days with maxima at or above 20 °C, which is the highest number of such days in August on record for the site, exceeding its previous record of 17 days set on August last year.

Further information

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Extremes in August 2014
Hottest day 27.4 °C at Gosnells City on the 17th
Warmest days on average 22.2 °C at Gosnells City
Coolest days on average 18.4 °C at Bickley
Coldest day 14.2 °C at Bickley on the 1st
Coldest night

1.8 °C at Jandakot Aero on the 6th

Coolest nights on average

9.1 °C at Jandakot Aero

Warmest nights on average 14.2 °C at Rottnest Island
11.9 °C at Swanbourne
Warmest night 17.8 °C at Rottnest Island on the 29th
17.3 °C at Medina Research Centre on the 29th
Warmest on average overall 17.0 °C at Rottnest Island
16.7 °C at Swanbourne
Coolest on average overall 13.8 °C at Bickley
Wettest overall 162.1 mm at Mundaring
Wettest day 70.8 mm at Mundaring on the 30th
Highest wind gust 104 km/h at Rottnest Island on the 17th

Record highest August temperature
Highest temperature
in August 2014 (°C)
Previous warmest
for August
Years of
record
Average for
August
Medina Research Centre 26.2 on the 17th 26.0 on the 29th in 2006 29 18.8
Rottnest Island 23.3 on the 17th = 23.0 on the 12th in 1976 49 17.9
Swanbourne 26.2 on the 6th = 26.2 on the 26th in 1998 21 18.8



Record highest August mean daily maximum temperature
Mean daily maximum
temperature
for August 2014 (°C)
Previous warmest
for August
Years of
record
Average for
August
Perth Metro 21.6 20.4 in 2013 117 19.0
Rottnest Island 19.8 19.4 in 2013 117 17.9
Perth Airport 21.5 20.6 in 2006 70 18.5
Pearce RAAF 21.5 20.2 in 2013 53 18.3
Medina Research Centre 21.2 20.5 in 2006 28 18.8
Jandakot Aero 21.1 20.1 in 2011 24 18.6
Gosnells City 22.2 20.8 in 2013 21 19.4
Bickley 18.4 17.2 in 2006 20 16.0
Swanbourne 21.5 20.2 in 2013 20 18.8
Garden Island HSF 19.6 19.3 in 2006 12 18.1



Record highest August daily minimum temperature
Highest daily minimum
temperature
in August 2014 (°C)
Previous warmest
for August
Years of
record
Average for
August
Medina Research Centre 17.3 on the 29th 16.6 on the 8th in 2013 29 8.1



Record highest August mean daily minimum temperature
Mean daily minimum
temperature
for August 2014 (°C)
Previous warmest
for August
Years of
record
Average for
August
Rottnest Island 14.2 = 14.2 in 2006 117 12.4

Highest August mean daily minimum temperature for at least 10 years
Mean daily minimum
temperature
for August 2014 (°C)
Most recent August
at least this warm
Years since
warmer
Average for
August
Pearce RAAF 10.2 11.2 in 1998 16 8.2
Perth Airport 10.2 10.6 in 1998 16 8.0
Gosnells City 10.9 11.3 in 1998* 15 8.9

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




Record highest August mean temperature
Mean daily
temperature
for August 2014 (°C)
Previous warmest
for August
Years of
record
Average for
August
Perth Metro 16.0 15.7 in 1983 117 13.6
Rottnest Island 17.0 16.7 in 2013 117 15.1
Perth Airport 15.9 15.3 in 1998 70 13.3
Pearce RAAF 15.9 15.4 in 1998 53 13.2
Medina Research Centre 15.7 15.6 in 2013 28 13.5
Jandakot Aero 15.1 14.9 in 2013 24 12.8
Gosnells City 16.5 15.8 in 2013 21 14.1
Bickley 13.8 13.2 in 2013 20 11.8
Swanbourne 16.7 16.2 in 2013 20 14.4
Garden Island HSF 16.2 = 16.2 in 2013 12 14.7



Summary statistics for August 2014
Maximum temperatures
for August
(°C)
Minimum temperatures
for August
(°C)
Rainfall
for August
(millimetres)
Mean for
August
2014
Diff
from
average
Highest for
August
2014
Mean for
August
2014
Diff
from
average
Lowest for
August
2014
Total for
August
2014
Average
for
August
Rank of
August
2014
Fraction of
August
average
Central Coast (district 09)
Bickley 18.4 +2.4 22.8 6th 9.2 +1.6 2.6 1st 157.2 171.9 average 91%
Garden Island HSF 19.6 +1.5 24.0 17th 12.8 +1.6 7.0 1st 81.6 90.5 low 90%
Gosnells City 22.2 +2.8 27.4 17th 10.9 +2.0 4.1 1st 106.1 125.8 average 84%
Jandakot Aero 21.1 +2.5 26.4 17th 9.1 +2.1 1.8 6th 109.4 126.0 average 87%
Medina Research Centre 21.2 +2.4 26.2 17th 10.3 +2.2 2.6 1st 67.2 113.2 v low 59%
Pearce RAAF 21.5 +3.2 26.4 17th 10.2 +2.0 2.9 1st 88.0 104.2 average 84%
Perth Airport 21.5 +3.0 26.8 17th 10.2 +2.2 3.1 1st 102.0 117.7 average 87%
Perth Metro 21.6 +2.6 26.9 17th 10.3 +2.1 3.8 3rd 107.0 133.3 low 80%
Rottnest Island 19.8 +1.9 23.3 17th 14.2 +1.8 8.7 1st 65.4 102.1 low 64%
Swanbourne 21.5 +2.7 26.2 6th 11.9 +1.9 5.3 1st 115.8 115.6 average 100%

Daily maximum temperature for August 2014
Central Coast (09)12345678910111213141516171819202122232425262728293031
Bickley14.216.916.818.220.522.816.518.417.619.819.718.219.520.420.722.615.117.115.417.616.718.419.621.518.218.621.519.215.115.1
Garden Island HSF17.816.918.721.021.823.218.317.720.022.522.818.619.219.418.419.524.018.419.218.920.017.719.320.722.017.619.621.918.617.216.6
Gosnells City18.719.820.822.525.626.819.922.021.523.123.518.721.323.124.525.327.420.021.118.520.621.923.025.520.822.425.021.518.5
Jandakot Aero17.418.919.621.423.825.918.820.520.722.922.919.721.122.322.323.426.419.119.619.020.619.820.521.323.820.220.923.321.218.117.7
Medina Research Centre18.019.019.922.224.625.618.220.320.722.723.419.820.020.523.622.226.219.820.020.421.319.320.822.824.219.921.023.118.518.0
Pearce RAAF17.719.619.020.723.525.119.721.220.122.923.019.822.122.822.623.626.419.518.819.621.619.621.622.924.520.221.625.523.518.718.0
Perth Airport17.319.619.721.424.225.819.321.620.823.522.918.720.822.323.523.726.819.320.219.621.519.422.022.224.720.621.725.322.318.718.2
Perth Metro17.719.719.821.324.226.618.921.021.424.023.219.320.523.623.023.926.919.720.019.421.519.821.522.324.520.721.424.322.318.718.1
Rottnest Island17.918.518.321.121.922.318.318.319.121.022.218.719.420.218.620.123.318.919.519.520.518.419.721.122.017.919.722.420.218.716.4
Swanbourne18.619.720.722.825.026.219.120.222.024.424.019.321.122.422.621.625.619.620.418.921.319.922.021.923.419.721.023.621.419.219.4

This table is very wide; you may have to scroll sideways to see all the days, and you may need to set the paper to 'landscape' to print.
The temperatures in this table are coloured by
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 difference from average


Daily minimum temperature for August 2014
Central Coast (09)12345678910111213141516171819202122232425262728293031
Bickley2.65.84.95.46.68.012.310.37.68.510.78.99.910.59.77.39.79.810.210.311.89.16.38.711.513.49.410.413.512.38.6
Garden Island HSF7.09.79.09.811.611.815.913.111.312.314.313.714.415.712.29.313.415.113.012.114.614.511.310.814.815.212.514.617.015.411.9
Gosnells City4.16.16.37.69.67.014.512.69.713.413.010.814.315.410.58.012.012.012.512.614.510.57.46.59.514.510.811.514.714.6
Jandakot Aero2.22.92.23.93.21.810.812.36.210.013.013.214.415.08.53.910.312.111.611.314.410.65.34.19.913.08.88.414.314.79.8
Medina Research Centre2.64.54.55.87.17.610.611.48.19.513.713.013.615.110.310.86.014.512.412.214.211.77.35.411.114.58.910.417.314.011.0
Pearce RAAF2.93.76.67.58.111.813.311.38.713.915.313.314.214.28.53.111.512.312.112.614.89.66.67.07.911.27.410.412.814.010.7
Perth Airport3.14.14.06.28.910.012.711.48.212.014.013.114.014.98.18.312.811.812.311.813.59.97.56.58.712.19.210.513.514.49.6
Perth Metro3.94.73.85.95.26.013.412.97.012.414.213.614.614.88.76.611.112.512.212.014.314.36.66.49.812.610.011.114.314.710.4
Rottnest Island8.710.411.411.814.315.416.414.612.713.815.214.414.716.114.713.615.014.814.114.414.914.513.314.616.515.514.415.317.814.611.8
Swanbourne5.38.36.28.710.010.015.112.99.413.014.813.714.415.311.19.612.913.912.512.414.314.57.49.812.215.311.312.516.514.710.6

This table is very wide; you may have to scroll sideways to see all the days, and you may need to set the paper to 'landscape' to print.
The temperatures in this table are coloured by
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 difference from average


Daily rainfall for August 2014
Central Coast (09)12345678910111213141516171819202122232425262728293031
Bickley 0.2 - - 0.2 - 5.0 8.6 0.2 - - - - - 0.2 - 21.2 33.4 0.4 10.6 10.6 - - 0.2 0.6 0.2 - - 65.0 0.6
Garden Island HSF - - 0.6 - - - 3.0 9.2 - - - - - - 0.2 - 0.2 9.8 7.4 1.4 9.0 1.6 0.2 - 0.2 0.2 - - 16.2 21.4 1.0
Gosnells City - - - - - - 4.2 4.4 - - - - - - 0.1 - - 15.0 20.0 0.5 9.0 9.0 1.0 - - 0.6 - - 0.1 40.9 1.3
Jandakot Aero 0.2 - - - - - 3.4 4.8 - - - - - - - - - 19.0 11.0 0.2 7.6 5.2 - - - 0.2 -
- 55.8 2.0
Jarrahdale - 0.2 0.4 0.2 - 0.4 1.6 12.8 0.2 0.2 - - - - 0.2 0.2 - 18.6 15.0 0.6 4.2 10.4 - 0.4 0.2 - - 0.2 - 39.2 0.8
Medina Research Centre - - - - - - 2.4 3.6 0.2 - - - - - 0.1 - - 13.0 5.2 1.2 5.6 6.0 - - 0.2 0.2 - - 0.2 20.8 8.5
Mundaring - - - - - - 5.6 3.6 - - - - 1.0 - 0.4 - - 14.4 50.4 0.6 4.4 8.2 0.2 - 0.1 0.6 - - - 70.8 1.8
Pearce RAAF - - - - - - 2.4 0.6 - - - - - - - - - 13.2 12.8 1.2
10.0 3.4 - - - 0.2 0.2 - - 41.8 2.2
Perth Airport - - - - - - 3.4 1.4 - - - - - - - - - 11.2 29.4 1.8 5.4 4.8 0.2 - - 0.4 - - - 43.4 0.6
Perth Metro - - - - - - 3.6 1.2 - - - - - - - - - 12.6 23.8 0.8 5.8 5.8 - - - - 0.2 - - 51.2 2.0
Roleystone - - - - - - 5.2 4.3 - - - - - - - - - 14.2 17.5 6.0 8.8 11.0 - - - 1.6 - - 0.1 63.8
Rottnest Island - - - - - - 3.6 5.0 - - - - - - - - - 10.8 6.2 4.2 8.0 2.8 - - - - 0.2 - - 23.4 1.2
Serpentine - - - - - - 1.4 12.2 - - - - - - - - - 18.4 20.0 0.4 5.0 7.4 - - - 0.6 0.2 - 21.8 33.6 0.6
Swanbourne - - 0.2 - - - 6.2 2.6 - - - - - - - 0.2 - 25.0 17.8 1.0 7.0 3.2 0.2 - 0.2 0.4 - - - 51.0 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 marked like this 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).
This table is very wide; you may have to scroll sideways to see all the days, and you may need to set the paper to 'landscape' to print.


Notes

A Monthly 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.

A Climate Summary is generally published on the first working day of each month.

This statement has been prepared based on information available at 2 pm on Monday 1 September 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.

Further information

Media
(03) 9669 4057
Enquiries