Perth in March 2015: wet mid-month

Rainfall in March 2015 was near average across much of the Perth metropolitan area with most of the rainfall recorded near the middle of the month. The highest daily rainfall in the Perth area was 17.4 mm at Karnet on the 15th, and its March rainfall total of 45.4 mm was the highest in Perth. Perth Metro recorded 15.6 mm on six rain days, which is near the long-term average of 19.5 mm.

Ex-tropical cyclone Olwyn moved past Perth to the east during the middle of the month and produced mainly light to moderate rainfall across the Perth area on the 13th and 14th. This low was followed by a weak cold front that moved up from the southwest and brought mostly light rainfall to Perth on the 18th, with some moderate falls in the hills. A trough near the west coast produced light showers for all sites in the evening on the 26th.

Mean maximum temperatures for March were mostly near average in the Perth metropolitan area, with means ranging from the mid-twenties on the offshore islands and in the hills, to the high-twenties and low-thirties on the coastal plain. A mean maximum temperature of 29.5 °C at Perth Metro was close to the long-term average.

The first half of March 2015 was mostly warm to hot with daily maxima often in the low thirties for coastal plain sites. The hottest day of the month in Perth was either the 12th or 13th, depending on the observing site, and a daily maximum temperature of 41.5 °C at Pearce RAAF on the 12th was the highest temperature of the month. The second half of March 2015 was mainly mild to warm with daily maxima commonly in the mid-twenties. Most sites saw their mildest day of the month on the 18th, and a daily maximum of 20.4 °C at Bickley on the 18th was the lowest maximum temperature of the month in Perth.

Mean minimum temperatures were mostly near average in Perth, with mean minima ranging from the mid-teens on the coastal plain and in the hills, to the high teens on the offshore islands. Most nights were mild to warm in the first half of the month with minimum temperatures ranging from the mid-teens to low-twenties. Bickley recorded the highest minimum temperature of the month in Perth on the 13th with 23.5 °C. The last two weeks saw generally cool nights with minima in the low-teens. Most sites recorded their coldest night on the 23rd, and Bickley recorded the lowest temperature of the month with 8.7 °C on that day. Perth Metro recorded a mean minimum temperature of 16.9 °C, which is close to the long-term average.

  • Highest temperature in March for three years at Pearce RAAF (41.5 °C on the 12th)
  • Rain mid-month from ex-tropical Olwyn and a weak cold front
  • Further information

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    Extremes in March 2015
    Hottest day 41.5 °C at Pearce RAAF on the 12th
    Warmest days on average 31.0 °C at Pearce RAAF
    Coolest days on average 25.8 °C at Rottnest Island
    27.2 °C at Bickley
    Coldest day 20.4 °C at Bickley on the 18th
    Coldest night 8.7 °C at Bickley on the 23rd
    Coolest nights on average 14.8 °C at Bickley
    Warmest nights on average 18.8 °C at Rottnest Island
    17.3 °C at Swanbourne
    Warmest night 23.5 °C at Bickley on the 13th
    Warmest on average overall 23.4 °C at Pearce RAAF
    Coolest on average overall 21.0 °C at Bickley
    Wettest overall 45.4 mm at Karnet
    Driest overall 15.6 mm at Perth Metro
    Wettest day 17.4 mm at Karnet on the 15th
    Strongest wind gust 74 km/h at Rottnest Island on the 22nd




    Summary statistics for March 2015
    Maximum temperatures
    (°C)
    Minimum temperatures
    (°C)
    Rainfall
    (millimetres)
    Mean for
    March
    2015
    Diff
    from
    average
    Highest for
    March
    2015
    Mean for
    March
    2015
    Diff
    from
    average
    Lowest for
    March
    2015
    Total for
    March
    2015
    Average
    for
    March
    Rank of
    March
    2015
    Fraction of
    March
    average
    Bickley 27.2 -0.9 36.5 12th 14.8 +0.3 8.7 23rd 41.8 25.4 high 165%
    Garden Island HSF 26.4 -0.8 33.7 13th 18.3 +0.1 13.1 23rd 16.2 14.7 average 110%
    Gosnells City 30.0 -0.6 38.2 12th     12.4 23rd 21.6 16.8 high 129%
    Jandakot Aero 29.6 -0.1 36.4 12th 15.4 0.0 9.0 24th 17.4 16.1 high 108%
    Medina Research Centre 29.3 -0.1 35.2 13th 16.3 +0.4 10.8 23rd 20.3 19.3 average 105%
    Pearce RAAF 31.0 +0.5 41.5 12th 15.7 -0.3 8.9 29th 26.8 15.1 high 177%
    Perth Airport 29.9 +0.2 38.6 12th 16.2 +0.3 10.8 28th 21.4 16.2 high 132%
    Perth Metro 29.5 -0.2 37.9 12th 16.9 +0.3 12.3 23rd 15.6 19.5 average 80%
    Rottnest Island 25.8 -0.3 31.1 13th 18.8 +0.1 13.6 23rd 22.4 14.3 high 157%
    Swanbourne 29.3 +0.3 37.2 12th 17.3 0.0 11.7 23rd 21.4 21.4 average 100%

    Daily maximum temperatures for March 2015
    12345678910111213141516171819202122232425262728293031
    Bickley29.825.329.429.830.130.330.730.531.431.433.036.532.929.523.223.123.920.421.928.322.621.021.424.525.727.324.325.528.827.523.4
    Garden Island HSF25.728.727.227.032.627.826.424.125.824.228.131.933.731.825.526.026.622.322.627.722.823.725.221.728.831.525.022.123.422.6
    Gosnells City32.131.833.833.533.832.233.233.135.238.235.733.126.526.226.824.225.632.025.024.525.127.329.030.527.131.228.425.6
    Jandakot Aero31.229.230.733.133.532.332.331.532.331.733.436.435.433.427.226.327.424.125.730.924.824.724.826.328.731.227.526.630.427.526.0
    Medina Research Centre31.329.630.332.633.832.532.528.931.729.433.435.035.233.026.725.728.223.725.231.024.525.025.525.228.531.427.025.029.227.2
    Pearce RAAF31.928.531.733.533.333.834.034.435.035.536.341.536.433.128.228.229.425.926.132.026.125.424.928.029.529.428.429.233.228.6
    Perth Airport31.528.432.033.033.233.133.632.233.133.034.838.636.432.726.726.026.624.625.831.625.025.024.427.828.630.327.626.931.728.125.9
    Perth Metro31.228.630.632.733.332.633.031.132.631.734.537.934.832.626.526.726.923.825.331.024.524.624.625.829.230.426.926.531.127.825.3
    Rottnest Island25.226.725.726.428.727.427.025.125.624.326.830.931.127.425.825.726.223.523.626.724.822.522.922.829.724.223.525.324.222.9
    Swanbourne30.130.931.633.235.333.131.728.831.428.233.537.234.832.927.627.627.324.226.331.324.626.426.025.129.932.026.224.926.824.725.8
    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 March 2015
    12345678910111213141516171819202122232425262728293031
    Bickley13.416.014.214.014.114.615.215.415.516.315.817.523.518.218.816.816.016.914.111.716.112.48.79.411.111.313.413.313.316.214.4
    Garden Island HSF17.318.917.618.418.819.719.419.619.218.319.221.520.720.621.921.121.519.517.916.318.616.513.114.015.916.818.215.415.218.3
    Gosnells City17.819.618.019.119.419.919.616.519.821.418.420.016.716.117.814.212.414.115.616.012.513.615.516.8
    Jandakot Aero16.518.616.717.517.816.615.917.815.711.614.619.017.120.121.317.116.619.415.312.316.113.69.99.014.415.914.410.110.711.914.7
    Medina Research Centre15.218.316.717.818.016.815.518.517.714.115.618.117.420.021.220.620.519.416.515.116.514.710.813.015.115.916.411.012.012.714.2
    Pearce RAAF17.318.518.017.417.918.415.016.917.511.313.517.618.120.820.017.015.918.716.113.615.413.611.613.712.816.517.610.78.911.216.0
    Perth Airport17.319.717.217.517.618.316.417.916.712.715.819.018.020.320.717.217.219.614.213.016.114.311.713.615.115.216.810.810.813.017.1
    Perth Metro17.319.617.517.618.018.618.319.517.415.616.619.818.720.721.318.818.519.515.614.616.615.012.313.114.915.615.012.412.814.317.3
    Rottnest Island18.016.217.718.619.220.320.020.220.119.720.421.921.920.421.219.920.719.118.017.120.117.013.614.916.217.518.118.117.320.519.3
    Swanbourne17.318.716.917.517.918.516.818.218.616.718.120.521.219.921.319.920.818.817.015.717.614.911.713.215.216.016.414.414.516.616.4
    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 March 2015
    12345678910111213141516171819202122232425262728293031
    Bickley - - - - - - - - - - - - - 10.4 11.2 2.2 - 10.0 2.8 - - - - - - - 5.2 - - - -
    Garden Island HSF - - - - - - - - - - - - - 9.6 2.6 - - 2.8 0.2 - - - - - - - 1.0 - -
    -
    Gosnells City - - - - - - - - - - - - 7.6 1.4 0.8 0.6 6.0 1.4 - - - - - - - 3.8 - - -
    Jandakot Aero - - - - - - - - - - - - - 5.2 1.4 0.8 - 7.0 0.4 - - - - - - - 2.6 - - - -
    Jarrahdale - - - - - - - - - - - - - 8.0 16.0 0.6 0.2 13.0 1.6 0.2 - - - - - - 1.8 0.4 - - -
    Medina Research Centre - - - - - - - - - - - - - 7.5 6.8 - - 3.2 1.6 - - - - - - - 1.2 - - - -
    Mundaring - - - - - - - - - - - - - 8.6 9.4 0.6 - 8.8 2.0 - - - - - - - 6.0



    Pearce RAAF - 0.8 - - - - - - - - - - - 9.0 5.4 4.4 0.2 2.4 0.2 - - - - - - - 4.4 - - - -
    Perth Airport - - - - - - - - - - - - - 7.2 4.6 1.4 - 4.0 0.8 - - - - - - - 3.4 - - - -
    Perth Metro - - - - - - - - - - - - - 4.8 2.4 0.2 - 4.6 0.8 - - - - - - - 2.8 - - - -
    Roleystone - - - - - - - - - - - - - 7.6 5.8 0.5 - 11.6 2.2 - - - - - - - 4.2



    Rottnest Island - 6.8 - - - - - - - - - - - 8.0 1.8 0.4 - 3.2 0.2 - - - - - -
    2.0 - - - -
    Serpentine - - - - - - - - - - - - - 8.4 16.6 - - 5.4 0.6 - - - - - - - 4.0 - - - -
    Swanbourne - - - - - - - - - - - - - 10.0 0.2 0.4 - 7.2 1.2 - - - - - - - 2.4 - - - -
    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 Wednesday 1 April 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