Perth in March 2012 : A hot, dry and sunny month

  • Rainfall: Very much below average
  • Maximum temperature: Very much above average
  • Minimum temperature: Near average

Rainfall

Generally dry conditions were observed across the Perth Metropolitan area during March 2012, with a number of stations recording no rainfall for the month, however, this is not unprecedented at this time of year and was also the case for most sites in March 2011. Medina Research Centre observed no rainfall, the first instance this has occurred in March in its 28 years of record. The only significant rainfall for the month in the Perth area was due to a weak cold front crossing the Southwest Land Division during the evening of the 29th and into the morning of the 30th, with a line of light showers moving through the Perth area late on the 29th. Rottnest Island recorded the heaviest daily fall for the month with just 1.4 mm in the 24 hours to 9am on the 30th.

Perth Metro recorded 0.2 mm of rainfall during March 2012, which is very much below average, and in fact the first month to see below average rainfall at Perth Metro since August 2011. The total rainfall for the three months from January to March 2012 at Perth Metro was 42.6 mm on 9 rain days, close to the average for this period of 41.6 mm on 8.6 rain days. Last year (2011) for the same three month period, Perth Metro recorded 30.6 mm on 7 days.

Maximum temperature

Very much above average daytime temperatures were observed across the Perth Metropoltian region during March 2012, primarily as a result of very hot conditions during the first half of the month. Heatwave conditions (three or more consecutive days with maximum temperatures of 35 °C or higher) were experienced from the 4th to the 6th at many metropolitan sites, due to a trough off the west coast directing hot northeasterly winds over the Perth area, before a brief respite from the heat was experienced on the 7th and 8th due to a weak front brushing the south coast. Temperatures rose again as a trough re-developed off the west coast, resulting in another heatwave for most sites from the 9th to the 12th, with several experiencing 2 or 3 days of maximum temperatures in the low forties. Cooler conditions were experienced for much of the remainder of the month, with the coolest day for March 2012 observed on the 30th due to a southerly change.

Perth Metro's mean maximum temperature in March was 31.4 °C, the third warmest March on record behind 31.9 °C in 2011 and 31.8 °C in 1978. The average maximum temperature for March for Perth Metro is 29.6 °C. Perth Metro's maxima ranged from 41.1 °C on the 11th, the hottest March day since the record for March at Perth Metro was set at 42.4 °C on 7 March 2007, to 22.8 °C on the 30th, the lowest March maximum at Perth Metro since 18.4 °C was recorded on 31 March 2008. Interestingly, Perth Metro's maximum temperature of 41.1 °C on the 11th was the highest temperature in WA on that day. On the 12th, the temperature at Perth Metro ranged from a minimum of 15.8 °C at 0514 WST to a maximum of 40.6 °C at 1153 WST, resulting in a diurnal temperature range (difference between minimum temperature and maximum temperature) of 24.8 °C, breaking the previous record for Perth Metro of 24.7 °C set on 23 March 2005 (minimum 17.2 °C to maximum 41.9 °C).

Perth Metro recorded two heatwaves during March 2012, and this has only occured on one other occasion at Perth Metro during March (in 1988) since temperature records commenced in 1897. These heatwaves also took the tally for the November 2011 to March 2012 period to eight, breaking the previous record of seven recorded in 1977/78. Perth Metro saw two heatwaves in each of December, January, February, and March.

After the second hottest January, a near average February, and the third hottest March, Perth Metro has seen it's third warmest start to the year since records commenced in 1897. The mean daily maximum temperature for January to March 2012 was 32.0 °C, only behind 32.9 °C in 2011 and 32.3 °C in 1978. The average for this period is 30.7 °C.

Minimum temperature

Minimum temperatures were generally close to average across most sites in the Perth area, apart from Rottnest Island which saw overnight temperatures 1.2 °C warmer than normal. The warmest nights for most sites were experienced during the second week of the month in conjunction with Perth's second heatwave of the month. Cooler nights were experienced in the latter part of the month, with the coolest night for most sites observed on the 31st.

Perth Metro's mean daily minimum temperature in March was 16.1 °C, below the average of 16.6 °C and the coolest March since 15.1 °C was recorded in 2009. Perth Metro's minima ranged from 20.7 °C on the 13th to 9.0 °C on the 31st.

March 2012 was the first month that Perth Metro had recorded a below average mean minimum temperature since October 2010.

Sunshine

Perth recorded an average daily sunshine of 10.6 hours in March 2012, the equal second sunniest March (equal with 2001 and 2007) since records commenced in 1898. The sunniest March on record at Perth Metro was last year (2011) with an average sunshine amount of 11.0 hours per day. The average daily sunshine for March is 9.6 hours.

Further information

Media
(03) 9669 4057
Enquiries

Extremes in March 2012
Hottest day 41.9 °C at Gosnells City on the 11th
Warmest days on average 32.3 °C at Gosnells City
Coolest days on average 28.0 °C at Rottnest Island
28.9 °C at Bickley
Coldest day 20.3 °C at Garden Island HSF on the 30th
20.8 °C at Bickley on the 30th
Coldest night 6.0 °C at Pearce RAAF on the 31st
Coolest nights on average 14.6 °C at Bickley
Warmest nights on average 19.1 °C at Rottnest Island
17.4 °C at Champion Lakes
Warmest night 23.8 °C at Rottnest Island on the 6th
22.1 °C at Bickley on the 12th
Wettest overall 1.4 mm at Rottnest Island
Wettest day 1.4 mm at Rottnest Island on the 30th
Highest wind gust 76 km/h at Rottnest Island on the 19th

Record lowest total March rainfall
Total rainfall
for March 2012 (mm)
Previous driest
for March
Years of
record
Average for
March
Medina Research Centre 0.0 0.2 in 2011 29 18.3



Summary statistics for March 2012
Maximum temperatures
for March
(°C)
Minimum temperatures
for March
(°C)
Rainfall
for March
(millimetres)
Mean for
March
2012
Diff
from
average
Highest for
March
2012
Mean for
March
2012
Diff
from
average
Lowest for
March
2012
Total for
March
2012
Average
for
March
Rank of
March
2012
Fraction of
March
average
Bickley 28.9 +0.8 38.1 12th 14.6 +0.1 10.0 31st 0 24.1 lowest 0%
Champion Lakes 30.5   39.6 11th 17.4   12.0 31st 0
Garden Island HSF 28.5 +1.1 37.7 11th 17.6 -0.7 13.5 31st 0.2 12.3 low 2%
Gosnells City 32.3 +1.8 41.9 11th         0 15.7 lowest 0%
Jandakot Aero 31.3 +1.6 40.2 11th 15.0 -0.4 7.0 31st 0.2 14.9 v low 1%
Medina Research Centre 31.1 +1.8 41.1 11th 15.8 -0.1 7.8 31st 0 18.3 lowest 0%
Pearce RAAF 32.0 +1.5 41.8 12th 15.9 -0.1 6.0 31st 0.6 14.3 v low 4%
Perth Airport 31.6 +1.9 40.9 11th 15.6 -0.3 7.6 31st 0 15.7 lowest 0%
Perth Metro* 31.4 +1.8 41.1 11th 16.1 -0.5 9.0 31st 0.2 19.4 low 1%
Rottnest Island 28.0 +1.9 37.5 11th 19.1 +0.4 15.4 31st 1.4 14.3 low 10%
Swanbourne 30.5 +1.5 39.4 11th 17.1 -0.3 11.5 31st 0 20.0 lowest 0%

Daily maximum temperature
Central Coast (09)12345678910111213141516171819202122232425262728293031
Bickley26.527.229.733.936.335.830.930.635.237.937.838.128.026.025.327.230.431.429.624.823.022.924.225.525.025.726.127.931.120.821.8
Champion Lakes28.829.331.235.036.737.330.832.637.738.239.638.529.728.727.929.032.333.529.926.225.125.726.527.427.226.527.330.431.222.223.3
Garden Island HSF30.230.029.432.933.736.824.527.134.032.637.731.429.927.928.730.533.531.424.324.426.127.327.928.525.922.723.324.025.220.322.2
Gosnells City31.032.637.040.132.333.239.040.041.940.831.129.530.033.534.831.727.626.327.529.028.528.631.333.723.525.0
Jandakot Aero29.830.031.936.037.938.830.333.637.738.940.239.930.929.029.230.333.434.129.727.626.326.627.428.128.627.027.230.231.422.924.2
Medina Research Centre30.031.033.036.537.639.628.332.239.037.741.139.931.129.227.030.734.733.627.827.426.727.128.028.727.925.626.630.430.022.023.8
Pearce RAAF30.030.333.136.939.039.232.533.939.441.140.641.831.529.128.530.633.334.231.427.426.126.727.029.828.428.428.430.734.423.024.8
Perth Airport29.930.432.936.739.238.831.633.538.340.440.940.430.929.028.730.233.034.829.827.725.725.927.429.127.227.527.730.833.122.824.4
Perth Metro30.430.932.736.338.038.929.433.538.939.541.140.631.229.228.930.433.334.229.327.526.426.227.429.227.326.627.429.633.122.824.0
Rottnest Island28.228.430.033.033.436.925.625.928.733.237.534.127.025.326.527.931.730.225.123.324.125.226.428.426.225.124.224.626.021.822.7
Swanbourne30.531.731.034.635.638.327.632.337.633.639.437.231.929.929.731.233.532.627.127.227.126.528.329.126.825.425.928.828.023.223.9

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
Central Coast (09)12345678910111213141516171819202122232425262728293031
Bickley12.511.612.915.819.019.119.015.013.919.817.122.117.912.712.211.313.317.115.911.312.212.712.412.613.914.713.614.214.213.810.0
Champion Lakes15.918.018.119.321.817.718.018.120.421.321.620.516.715.915.317.521.617.913.415.213.316.017.118.214.813.316.218.317.312.0
Garden Island HSF17.016.618.217.714.317.919.118.418.619.321.115.821.116.616.215.218.820.019.816.415.715.315.818.018.717.917.717.318.717.513.5
Gosnells City16.017.617.516.518.918.022.018.920.316.815.218.020.517.213.215.613.215.518.014.212.519.217.411.5
Jandakot Aero16.115.316.812.112.815.512.817.217.516.019.315.219.615.915.714.515.720.214.611.415.112.314.516.315.612.58.915.615.917.17.0
Medina Research Centre16.315.416.915.316.217.915.017.917.917.820.514.319.915.615.514.517.417.315.913.414.913.412.817.517.014.210.816.516.917.47.8
Pearce RAAF16.616.418.315.513.718.012.518.118.416.719.013.718.116.616.015.019.421.315.312.416.615.315.817.718.014.89.512.617.916.26.0
Perth Airport16.215.617.014.015.218.312.918.417.615.618.514.520.315.216.114.716.018.614.613.815.913.315.316.117.114.810.013.518.117.77.6
Perth Metro16.315.616.314.214.816.715.618.017.817.420.215.820.716.316.114.715.616.716.414.415.914.415.716.716.315.813.216.917.317.69.0
Rottnest Island17.017.619.021.021.323.822.218.918.821.922.122.321.017.116.616.019.022.421.417.316.216.416.418.218.819.119.118.219.817.715.4
Swanbourne16.215.917.117.618.821.419.417.618.119.821.519.519.916.414.416.119.217.914.115.413.715.417.016.915.314.615.917.817.911.5

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
Central Coast (09)12345678910111213141516171819202122232425262728293031
Bickley - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Champion Lakes - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Garden Island HSF - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 0.2 -
Gosnells City - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Jandakot Aero - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 0.2 -
Jarrahdale - - - - - - - - - - - - - - - - - - - - - - - - - - - 0.2 - 0.2 -
Medina Research Centre - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Mundaring




























1.2
Pearce RAAF - - - - - - - - - - - - - - - - - - - - - - -

- - - - 0.6 -
Perth Airport - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Perth Metro - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 0.2 -
Rottnest Island - - - - - - - - - - - - - - - - - - - - - -
- - - - - - 1.4 -
Serpentine - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 0.2 0.2
Swanbourne - - - - - - - - - - - - - -
- - - - - - -
- - - - - - - -

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.

This statement has been prepared based on information available at 11 am on Monday 2 April 2012. 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.
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.

Records in this summary are based on sites with at least 10 years of data.

*Official Perth observations have been recorded at several different sites with varying instrumentation over the years, and these changes can affect the continuity of the climate record. For the current Mt Lawley site, the most significant changes of this kind relate to minimum temperature and rain days.

For that reason, current mean temperature and rain-day data quoted here are based only on readings from the Mt Lawley site, which commenced observations in 1993. Sunshine recordings are from Perth Airport and for similar reasons current means use only Perth Airport data, which commenced in 1993.

For PDF files of Perth Metro climate statistics for other months, please click here for extremes and here for averages.

Further information

Media
(03) 9669 4057
Enquiries