This statement was prepared before all data for the period were available. This may affect some of the statistics presented.

Perth in March 2011: A hot and dry month

This statement was prepared before all data for the period were available. This may affect some of the statistics presented.
  • Rainfall: Very much below average; lowest on record at a few sites.
  • Maximum temperature: Very much above average; highest on record at several sites..
  • Minimum temperature: Very much above average; highest on record at several sites.

Rainfall

Rainfall across the Perth metropolitan area during March 2011 was very much below average, with Pearce RAAF, Medina Research Centre and Swanbourne observing their lowest March rainfall totals on record. Swanbourne observed zero rainfall for March, the first time in 17 years of record, while zero rainfall was also observed at Perth Airport, Jandakot Aerodrome, Perth Metro and Rottnest Island, however this is not unprecedented at these sites.

Moderate to heavy rainfall was reported in eastern parts of the Perth metropolitan area in the 24 hours to 9am on 1 March 2011, though this rain fell during severe thunderstorms in the afternoon of 28 February 2011 (see the Perth February monthly climate summary for further information). Mundaring, in the Perth hills, observed its second highest March daily rainfall on record during this event, with the 82.0 mm in the 24 hours to 9am on the 1st only behind the 91.4 mm observed in the 24 hours to 9am on 9 March 1934. Mundaring also observed its 5th highest March monthly rainfall, largely due to the heavy rain during the afternoon of 28 February.

Perth Metro recorded zero rainfall during March 2011 which has occurred on six other occasions at Perth Metro, the last occurrence being in 2004. The average for March is 19.5 mm on 4.4 rain days. Last March (2010), Perth Metro recorded 40.4 mm on 2 rain days, while the wettest March on record was 145.2 mm in 1934. Up to the 31 March, Perth Metro has not recorded rainfall for 58 days, since 0.4 mm was observed on 1 February 2011, the longest dry spell since a 78 day run between 21 November to 6 February 2010. Perth Metro's longest dry spell, since records commenced in 1876, was 83 days between 15 December 1974 to 7 March 1975. As a result of the very long dry spell experienced over the last two months, Perth Metro has broken its lowest rainfall record for the February to March period, with just 0.4 mm of rainfall observed in February and March combined. The previous record was 0.8 mm in 1877 and 1973, whilst the average for the two-months combined (February-March) is 32.2 mm.

Maximum temperature

Very much above average mean maximum temperatures were observed across the Perth metropolitan area during March 2011, with daily temperatures mostly 2 to 3 °C above normal. Perth Metro, Perth Airport, Jandakot Aerodrome and Bickley broke their highest March mean daytime temperature records, while Rottnest Island observed its second highest mean maximum temperature for March with 28.3 °C, only behind the record of 29.3 °C set in 1888. Bickley observed a mean maximum temperature of 30.5 °C, the first time in 17 years of record that the site has registered a mean maximum temperature of over 30 °C during March.

An extended heatwave (three or more days of 35 °C or more) that began on 21 February ended on 1 March, however, hot weather persisted through to the 4th. After a brief respite, hot days returned during the middle and end of the month when another heatwave was experienced from the 24th to 26th (the latest autumn heatwave for 26 years at Perth Metro). Perth has experienced a number of heatwaves during March, but mostly during the first half of the month, with the latest heatwave at Perth Metro recorded from 9 to 11 April 1910.

Perth Metro's mean daily maximum temperature in March 2011 was 31.9 °C, which is the hottest March on record, breaking the previous record of 31.8 °C set in 1978. The average at Perth Metro for March is 29.5 °C. Daily maxima during March 2011 ranged from a mild 26.6 °C on the 6th to a hot 36.4 °C on the 25th.

A number of sites observed their highest number of hot days (32 °C or more) in March on record including; Pearce RAAF with 23 hot days (previous record of 21 in 1983), Perth Airport with 21 hot days (previous record of 19 in 1983), Gosnells City with 20 hot days (previous record of 18 in 1995), Perth Metro with 18 hot days (previous record of 17 in 1983), Jandakot Aerodrome with 19 hot days (previous record of 17 in 1998), Swanbourne with 14 hot days (previous record of 12 in 1994), Bickley with 12 hot days (equal with record of 12 in 2006).

Very hot conditions have been experienced across the Perth metropolitan region during the first three months of 2011, with most sites 2 to 3 °C above normal and hottest on record. Perth Metro's mean daily maximum temperature for the three months of January to March is 32.9 °C, which is the hottest start to the year since records commenced in 1897, breaking the previous record of 32.3 °C set in 1978. The average for the three months January to March period is 30.5 °C.

A number of sites across the Perth metropolitan area observed a record number of hot days during the first three months of 2011 including; Pearce RAAF with 69 hot days (previous record of 58 in 2010), Perth Airport with 64 hot days (previous record of 52 in 1978), Perth Metro with 58 hot days (previous record of 47 in 1978), Jandakot Aerodrome with 61 hot days (previous record of 50 in 2010), Swanbourne with 45 hot days (previous record of 35 in 2008), Bickley with 47 hot days (previous record of 41 in 2010).

Minimum temperature

Very much above average mean minimim temperatures were observed across the Perth metropolitan area during March 2011, with overnight temperatures mostly 2 to 3 °C above normal. Rottnest Island, Jandakot Aerodrome and Swanbourne broke their highest March night-time temperature records.

Perth Metro's mean daily minimum temperature in March was 18.6 °C, the 9th warmest March on record and the warmest since the record of 20.0 °C in 1988. The average for March at Perth Metro is 16.5 °C. Daily minima during March 2011 ranged from a mild 14.1 °C on the 27th to a warm 22.8 °C on the 15th.

An extended run of warm nights (20 °C or more) across the Perth region that began on 14 February came to an end on 2 March. Perth Metro observed 17 consecutive warm nights during this period, easily passing the previous record of 13 nights observed on two occasions, in 1985 (17 February to 1 March) and 1990 (23 February to 7 March).

Very warm overnight conditions have been experienced across the Perth metropolitan region during the first three months of 2011, with a number of sites 2 to 3 °C above normal and warmest on record. Perth Metro's mean daily minimum temperature for the three months from January to March is 19.7 °C, which is the third warmest start to the year on record since the 19.8 °C in 1985. The record is 20.4 °C in 1978 whilst the average for the three months from January to March is 17.5 °C.

A number of sites across the Perth metropolitan area observed a record number of warm nights (20 °C or more) during the first three months of 2011 including; Pearce RAAF with 42 warm nights (previous record of 40 in 1978), Perth Airport with 37 warm nights (equal record with 1978), Jandakot Aerodrome with 33 warm nights (previous record of 27 in 1990), Swanbourne with 41 warm nights (previous record of 37 in 1995), Rottnest Island with 60 warm nights (previous record of 55 in 1995).

Wind and sunshine

The highest wind gust for March 2011 in the Perth metropolitan area was observed at Perth Airport (80 km/h at 0237 WST on the 30th) as a strong pressure gradient over the south of WA caused gusty easterly winds.

Perth recorded an average daily sunshine of 11.0 hours in March, which the sunniest March on record. The previous record for March was 10.6 hours per day in 2001 and 2007. The average sunshine for March in Perth is 9.5 hours per day.

Further information

Media
(03) 9669 4057
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Extremes in March 2011
Hottest day 37.5 °C at Gosnells City on the 25th
Warmest days on average 33.3 °C at Pearce RAAF
Coolest days on average 28.8 °C at Garden Island HSF
Coldest day 23.3 °C at Garden Island HSF on the 12th
Coldest night 11.4 °C at Pearce RAAF on the 28th
Coolest nights on average 16.2 °C at Bickley
Warmest nights on average 20.8 °C at Rottnest Island
Warmest night 24.2 °C at Pearce RAAF on the 4th
Wettest overall 82.4 mm at Mundaring
Wettest day 82.0 mm at Mundaring on the 1st
Highest wind gust 80 km/h at Perth Airport on the 30th

Highest total March rainfall for at least 10 years
Total rainfall
for March 2011 (mm)
Most recent March
at least this wet
Years since
wetter
Average for
March
Mundaring 82.4 90.3 in 1990 21 23.1



Record lowest total March rainfall
Total rainfall
for March 2011 (mm)
Previous driest
for March
Years of
record
Average for
March
Pearce RAAF 0.2 0.3 in 1973 56 14.5
Medina Research Centre 0.2 1.3 in 2004 28 19.0
Swanbourne 0.0 0.8 in 2004 18 21.1
Garden Island HSF 0.0 2.2 in 2002 10 13.5



Record highest March mean daily maximum temperature
Mean daily maximum
temperature
for March 2011 (°C)
Previous warmest
for March
Years of
record
Average for
March
Perth Airport 32.8 32.0 in 1978 66 29.7
Jandakot Aero 32.5 31.2 in 1995 20 29.5
Bickley 30.5 29.6 in 1994 17 28.0
Perth Metro* 31.9 31.8 in 1978 114 29.5
Swanbourne 31.1 30.0 in 2010 17 28.8



Record highest March mean daily minimum temperature
Mean daily minimum
temperature
for March 2011 (°C)
Previous warmest
for March
Years of
record
Average for
March
Rottnest Island 20.8 20.6 in 1978 120 18.0
Jandakot Aero 17.9 17.1 in 2005 20 15.2
Swanbourne 19.1 19.0 in 2005 17 17.3


Summary statistics for March 2011
Maximum temperatures
for March
(°C)
Minimum temperatures
for March
(°C)
Rainfall
for March
(millimetres)
Mean for
March
2011
Diff
from
average
Highest for
March
2011
Mean for
March
2011
Diff
from
average
Lowest for
March
2011
Total for
March
2011
Average
for
March
Rank of
March
2011
Fraction of
March
average
Bickley 30.5 +2.5 34.2 25th 16.2 +1.8 12.6 13th 4.2 24.7 low 17%
Champion Lakes     35.1 25th 19.6   16.5 13th 19.4
Garden Island HSF 28.8 +1.6 36.2 1st 20.0 +1.9 16.7 13th 0 13.5 lowest 0%
Jandakot Aero 32.5 +3.0 36.1 25th 17.9 +2.7 12.9 11th 0 15.3 lowest 0%
Pearce RAAF 33.3 +2.8 37.0 4th 18.3 +2.4 11.4 28th 0.2 14.5 lowest 1%
Perth Airport 32.8 +3.1 37.0 25th 18.5 +2.6 12.5 28th 0 15.9 lowest 0%
Perth Metro* 31.9 +2.4 36.4 25th 18.6 +2.1 14.1 27th 0 19.9 lowest 0%
Rottnest Island 20.8 +2.8 34.4 1st 20.8 +2.2 17.2 13th 0 16.7 lowest 0%
Swanbourne 31.1 +2.3 37.0 1st 19.1 +1.8 15.8 13th 0 21.1 lowest 0%

Daily maximum temperature
Central Coast (09)12345678910111213141516171819202122232425262728293031
Bickley32.330.032.033.528.626.127.429.832.532.426.725.828.132.433.130.430.830.428.227.129.231.331.632.534.233.032.732.230.729.9
Champion Lakes34.232.133.833.928.326.427.630.333.432.027.227.029.834.334.232.131.931.028.329.530.831.934.935.134.833.933.032.632.4
Garden Island HSF36.233.932.533.325.624.224.024.825.626.525.723.329.732.734.934.727.827.124.223.630.429.825.227.930.232.831.226.928.430.9
Gosnells City35.335.836.530.026.029.232.034.433.929.031.436.633.932.032.532.433.233.236.437.537.035.534.834.2
Jandakot Aero36.033.735.235.929.827.628.130.832.732.227.927.831.135.936.134.631.230.829.129.231.533.032.135.436.135.634.433.533.833.0
Medina Research Centre36.133.935.736.428.026.727.329.031.332.026.826.831.235.136.334.330.730.027.828.531.832.530.335.235.336.034.2
Pearce RAAF35.233.134.837.030.328.530.032.434.935.229.128.930.935.235.833.834.032.830.630.532.534.135.236.236.235.134.434.834.232.9
Perth Airport35.633.135.136.429.428.028.731.433.332.728.628.331.135.435.633.832.731.229.729.732.134.032.036.037.035.634.834.933.932.9
Perth Metro34.833.034.335.129.026.628.029.732.232.027.627.030.834.935.433.432.029.928.127.831.532.131.235.236.435.134.233.732.932.5
Rottnest Island34.430.232.931.926.425.224.625.526.226.925.424.527.431.033.031.327.327.325.423.928.327.927.530.932.330.526.426.829.2
Swanbourne37.034.335.533.528.227.026.728.229.230.026.926.731.936.836.834.830.028.126.927.132.230.027.533.136.033.132.728.931.033.6

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 minimum temperature
Central Coast (09)12345678910111213141516171819202122232425262728293031
Bickley17.616.915.919.419.015.613.714.215.017.814.413.712.615.018.715.717.517.317.013.613.117.818.517.116.817.817.218.015.515.114.8
Champion Lakes21.521.020.124.022.216.717.517.818.820.217.017.616.519.422.820.021.521.117.416.617.220.620.920.721.619.619.819.219.218.9
Garden Island HSF22.021.520.622.622.619.117.818.718.921.518.917.416.719.823.220.521.320.220.618.117.622.020.620.521.420.818.018.419.819.319.8
Gosnells City20.722.720.422.016.517.016.919.019.916.116.719.620.021.516.015.516.519.821.421.518.017.119.219.2
Jandakot Aero21.421.119.719.621.515.415.216.318.217.012.914.915.919.422.619.920.717.216.614.916.820.117.518.720.219.613.213.817.218.718.6
Medina Research Centre21.621.019.921.522.314.716.217.016.515.514.015.416.418.822.820.220.616.820.420.821.116.013.4
Pearce RAAF21.821.820.524.221.816.015.917.017.915.115.816.116.920.622.919.920.917.515.613.917.421.714.418.421.222.014.411.417.618.619.4
Perth Airport21.320.519.621.522.216.417.418.118.017.113.917.516.518.822.819.320.719.015.716.616.820.916.219.520.921.815.612.519.118.518.5
Perth Metro21.320.719.520.822.317.817.115.317.717.316.716.916.219.122.819.420.717.618.116.916.719.419.720.620.920.614.114.418.718.518.4
Rottnest Island22.222.021.123.822.520.018.519.019.422.220.218.617.220.323.620.821.221.621.718.518.021.221.122.822.622.021.220.319.820.3
Swanbourne21.820.920.222.121.717.817.316.117.219.016.815.915.819.123.419.720.719.218.116.516.720.119.620.621.921.518.516.418.618.918.9

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 rainfall
Central Coast (09)12345678910111213141516171819202122232425262728293031
Bickley 4.2 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Champion Lakes 19.2 0.2 - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Garden Island HSF - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Gosnells City 19.0 - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Jandakot Aero - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Jarrahdale 9.6 - - - - - - - - - - - - - - - - - - 0.2 - 0.4 - - - - - - - - -
Medina Research Centre 0.2 - - - - - - - - - - - - - - - - - - - - - - - - - - -


Mundaring 82.0
















0.2

0.2








Pearce RAAF - - - - - - - - - - - - - - - - 0.2 - - - - - - - - - - - - - -
Perth Airport - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Perth Metro - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Rottnest Island - - - - - - - - - - - - - - - - - - - - - - -
- - - - - - -
Serpentine 0.4 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
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

This statement was prepared before all data for the period were available. This may affect some of the statistics presented.

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 12 pm on Thursday 31 March 2011. 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