Perth in February 2015: An unusually humid month

Perth Metro experienced unusually humid conditions in February, and in fact recorded its second most humid February from records going back to 1942. Only February 1955 was more humid.

Rainfall in February 2015 was above average on the coastal plain and in the hills with most rainfall recorded as a result of showers and thunderstorms at the start of the month. The highest daily rainfall in the Perth area was 24.4 mm at Pickering Brook on the 3rd. The highest monthly rainfall total was 38.6 mm at Midland, which was its wettest February for twenty-two years, since 1993, when a monthly total of 75.0 mm was recorded. Perth Metro recorded 23.4 mm, almost double its February average, and the wettest February at the site for three years, since 23.6 mm was recorded in February 2012.

Mean maximum temperatures for February were near average for most sites, but above average in the eastern suburbs on the coastal plain, with means ranging from the high-twenties on the offshore islands, to the low-thirties on the coastal plain and in the hills, and to the mid-thirties in inland northeast suburbs. A mean maximum temperature of 32.3 °C at Perth Metro, although 0.7 °C above average, was the lowest in February for three years, since February 2012 when a mean maximum of 31.1 °C was recorded.

For most coastal plain sites, days were mainly warm to hot with daily maxima ranging from the high-twenties to mid-thirties. Very hot days with daily maxima in the high-thirties to low-forties occurred on 3rd, 8th, and 24th, and a daily maximum temperature of 42.1 °C at Pearce RAAF on the 8th was the highest temperature of the month in the Perth metropolitan area. A mild day with daily maxima in the mid-twenties occurred on the 14th, and a daily maximum of 21.7 °C at Garden Island was the lowest maximum temperature of the month in Perth.

Mean minimum temperatures were near average to above average in Perth in February, with mean minima ranging from the mid-to-high teens in coastal plain and hills sites, to close to 20 °C on the offshore islands. Most nights were mild with minimum temperatures in the high-teens to low-twenties, with a few cool nights with minima in the low to mid-teens on the 15th and 16th, and from the 21st to 23rd. The warmest night of the month varied across the metropolitan area, but a minimum temperature of 22.8 °C both at Garden Island and Gosnells City on the 17th was the highest minimum of the month recorded in Perth. The coolest night was the 15th throughout the metropolitan area with the lowest temperature recorded in the month being 11.1 °C at Bickley on that day. Perth Metro recorded a mean minimum temperature of 19.3 °C, which is 1.0 °C above the long-term average, and the warmest February for two years, since a mean minimum of 19.4 °C was recorded in February 2013.

Perth Airport recorded thunderstorms on three consecutive days from the 1st to 3rd. Three consecutive days with thunderstorms has only occurred in February at the airport on one other occasion since records commenced in 1944, from 17 to 19 February 1978. The average number of thunder days at Perth Airport in February is one, and the record for the month is a total of four days in 1992. As a result of the thunderstorms, Rottnest Island recorded a wind gust to 111 km/h early on the 2nd.

  • second most humid February on record since 1942
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    Extremes in February 2015
    Hottest day 42.1 °C at Pearce RAAF on the 8th
    Warmest days on average 34.7 °C at Pearce RAAF
    Coolest days on average 27.5 °C at Rottnest Island
    31.2 °C at Bickley
    31.2 °C at Swanbourne
    Coldest day 21.7 °C at Garden Island HSF on the 14th
    23.6 °C at Bickley on the 14th
    Coldest night 11.1 °C at Bickley on the 15th
    Coolest nights on average 16.9 °C at Bickley
    Warmest nights on average 20.1 °C at Garden Island HSF
    20.1 °C at Rottnest Island
    19.4 °C at Gosnells City
    Warmest night 22.8 °C at Garden Island HSF on the 17th
    22.8 °C at Gosnells City on the 17th
    Warmest on average overall 26.4 °C at Pearce RAAF
    Coolest on average overall 23.8 °C at Rottnest Island
    24.0 °C at Bickley
    Wettest overall 38.6 mm at Midland
    Wettest day 24.4 mm at Pickering Brook on the 3rd
    Strongest wind gust 111 km/h at Rottnest Island on the 2nd

    Highest February total rainfall for at least 20 years
    Observed
    (mm)
    Most recent
    higher
    Years since
    higher
    Average for
    February
    Pearce RAAF 32.6 97.0 in 1992 23 12.2
    Midland 38.6 75.4 in 1993 22 13.1



    Summary statistics for February 2015
    Maximum temperatures
    (°C)
    Minimum temperatures
    (°C)
    Rainfall
    (millimetres)
    Mean for
    February
    2015
    Diff
    from
    average
    Highest for
    February
    2015
    Mean for
    February
    2015
    Diff
    from
    average
    Lowest for
    February
    2015
    Total for
    February
    2015
    Average
    for
    February
    Rank of
    February
    2015
    Fraction of
    February
    average
    Bickley 31.2 +0.5 37.8 8th 16.9 +1.1 11.1 15th 27.4 19.5 high 141%
    Garden Island HSF 28.1 -0.5 36.9 24th 20.1 +0.6 14.9 15th 5.6 8.0 high 70%
    Gosnells City 33.3 +0.1 39.9 3rd 19.4 +0.6 15.2 15th        
    Jandakot Aero 32.4 +0.7 38.6 24th 18.1 +1.0 13.3 15th 26.4 16.3 high 162%
    Medina Research Centre 32.5 +1.0 39.6 3rd 18.5 +0.9 14.0 15th 15.7 18.8 high 84%
    Pearce RAAF 34.7 +1.4 42.1 8th 18.1 +0.5 14.2 15th 32.6 12.2 high 267%
    Perth Airport 33.1 +1.2 39.6 8th 18.6 +1.1 14.9 15th 27.0 14.4 high 188%
    Perth Metro 32.3 +0.7 39.5 8th 19.3 +1.0 14.9 15th 23.4 8.8 high 266%
    Rottnest Island 27.5 +0.2 35.0 24th 20.1 +0.6 15.5 15th 8.0 7.3 high 110%
    Swanbourne 31.2 +0.5 37.6 3rd 19.2 +0.5 13.6 15th 20.4 7.2 high 283%

    Daily maximum temperatures for February 2015
    12345678910111213141516171819202122232425262728
    Bickley30.829.135.230.729.930.633.537.834.535.435.328.626.023.628.432.730.234.332.628.426.928.830.337.035.733.725.828.0
    Garden Island HSF33.833.433.331.427.224.427.532.225.227.130.925.724.621.725.129.328.228.625.224.722.824.134.436.928.729.823.427.6
    Gosnells City34.032.839.933.832.331.936.536.036.237.527.825.531.536.233.835.330.227.931.534.338.837.127.031.4
    Jandakot Aero33.832.338.132.730.830.433.538.632.634.836.429.726.924.929.135.333.333.531.929.426.231.133.938.636.334.726.731.2
    Medina Research Centre33.734.039.633.230.729.035.036.632.033.136.229.526.526.528.035.333.833.231.429.026.030.234.139.135.9
    Pearce RAAF34.731.538.534.833.832.837.142.136.738.138.831.529.527.231.937.434.138.735.632.830.032.834.541.938.936.328.331.8
    Perth Airport33.732.639.133.531.531.035.539.633.435.437.031.627.325.730.436.033.535.232.530.028.432.133.839.536.534.627.131.1
    Perth Metro33.831.939.132.630.929.732.839.533.734.936.430.326.924.429.434.032.534.932.430.326.729.633.838.436.033.626.130.8
    Rottnest Island31.931.634.227.927.825.725.831.625.526.227.827.625.523.424.127.226.528.426.425.324.224.728.235.028.427.425.125.3
    Swanbourne35.734.337.630.728.228.232.034.628.631.435.428.927.125.029.535.731.431.928.528.626.728.935.037.333.130.726.331.4
    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 February 2015
    12345678910111213141516171819202122232425262728
    Bickley16.816.917.918.817.015.415.016.818.219.516.118.119.115.211.113.119.421.618.915.914.113.712.417.720.420.818.114.5
    Garden Island HSF21.220.521.121.719.618.919.320.420.921.720.322.020.819.914.918.122.821.521.619.718.618.315.821.120.421.821.017.9
    Gosnells City21.020.220.922.718.618.419.421.019.120.218.215.217.622.819.419.815.815.616.221.322.321.118.5
    Jandakot Aero20.719.620.119.916.716.918.619.818.315.619.421.219.818.513.315.518.616.417.717.815.214.815.520.519.120.820.216.1
    Medina Research Centre20.519.420.119.718.017.119.020.019.716.019.421.119.619.014.017.019.717.219.116.616.015.015.021.619.722.0
    Pearce RAAF20.819.719.721.417.317.519.020.418.715.819.820.320.117.614.215.818.815.416.216.114.314.415.721.419.119.920.416.7
    Perth Airport20.319.820.519.017.218.618.820.518.116.619.721.421.219.014.915.919.416.318.518.015.715.715.920.820.020.521.018.3
    Perth Metro20.919.720.119.818.918.519.220.619.918.520.021.921.519.114.917.118.618.219.719.816.717.116.121.021.521.621.118.3
    Rottnest Island21.220.822.522.020.819.719.620.220.221.020.222.120.418.815.518.420.721.220.720.419.019.316.220.020.721.120.518.5
    Swanbourne21.219.320.121.619.317.719.020.020.719.319.820.920.518.813.617.320.520.819.418.016.417.015.721.920.620.820.716.7
    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 February 2015
    12345678910111213141516171819202122232425262728
    Bickley - 11.6 13.4 2.2 0.2 - - - - - - - - - - - - - - - - - - -
    Garden Island HSF - 2.4 3.2 - - - - - - - - - - - - - - - - - - - - - - - - -
    Gosnells City - - - - - - - -
    - -

    - - - - - - - - - - - - - - -
    Jandakot Aero - 6.6 17.6 2.2
    - - - - - - - - - - - - - - - - - - - - - - -
    Jarrahdale - - 2.2 1.6 - - - - - - - - - 0.2 - - - - - - - - - - - - 0.4 -
    Medina Research Centre - 3.8 11.8 0.1 - - - - - - - - - - - - - - - - - - - - - -

    Mundaring - 8.8 11.0 9.6 - - - - - - - - 0.2 - - - - - - - - - - - - - 0.4
    Pearce RAAF - 16.2 12.2 4.2 - - - - - - - - - - - - - - - - - - - - - - - -
    Perth Airport - 9.4 13.4 4.2 - - - - - - - - - - - - - - - - - - - - - - - -
    Perth Metro - 9.6 11.8 1.6 - - - - - - - - - 0.4 - - - - - - - - - - - - - -
    Roleystone - 5.8 11.6 2.6 - - - - - - - - - - - - - - - - - - - - - - 0.6
    Rottnest Island - 3.0 0.2 4.8 - - - - - - - - - - - - - - - - - - - - - - - -
    Serpentine - 4.2 11.8 4.4 - - - - - - - - - - 0.2 - - - - - - - - - - - 0.2 0.2
    Swanbourne - 9.4 10.2 0.4 0.2 - - - - 0.2 - - - - - - - - - - - - - - - - - -
    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

    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 10 am on Tuesday 3 March 2015. 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.

    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