Perth in March 2010: A dry spell ended by a wild storm

  • Above average rainfall
  • Above average mean maximum temperature
  • Above average mean minimum temperature
  • A severe storm in Perth on the 22nd caused significant damage

Rainfall

March rainfall across the Perth metropolitan area was above average, though rainfall totals were largely the result of one storm event toward the end of the month. The Perth region didn't register any significant rainfall for the first 21 days of March, following on from one of the driest summers on record as Perth Airport recorded 122 days without measurable rainfall, easily its longest dry spell in 66 years of rainfall recording. Although there were some showers on the 21st, mainly in the hills, severe storms swept through the Perth metropolitan area on the afternoon of Monday the 22nd, bringing the first significant rainfall to Perth since the 19th November 2009. The storm was considered to be one of the worst storms in Perth's history in terms of power outages and damage, caused mainly by large hail (up to 6 cm) and flash flooding. The highest daily rainfall total recorded in Perth during the event was 66.8 mm at Wanneroo DAFWA, whilst Jarrahdale recorded 57.2 mm. Perth Airport (42.2 mm) and Gosnells (53.0 mm) reported their highest daily March rainfall on record as a result of the storms, whilst Perth Metro registered 40.2 mm in the 24 hours to 9am on the 23rd, its fifth highest March daily rainfall since records began in 1876. For more details of the severe thunderstorms in Perth, please read the storm summary.

Perth Metro recorded 40.4 mm of rainfall on 2 days in March, compared with the average of 19.4 mm on about 5 days. This is Perth Metro's wettest March since 52.2 mm was recorded in March 2005. Historically, March rainfall in Perth has ranged from nil on 6 occasions, to 145.2 mm in 1934. Last March, Perth Metro registered 6.8 mm of rainfall on 6 days.

Maximum temperature

Mean maximum temperatures for March 2010 were above average across the Perth metropolitan area. Means were approximately 1 °C above average for most sites, and Swanbourne recorded its hottest March in 16 years of record. As is typical for March, temperatures in the first half of the month were much higher than during the second half of the month.

The first two days of March saw much of Perth in a heatwave (three or more days with daily maximum temperature over 35°C) that commenced on the 24th February. This was followed by a cooler change but hot days returned toward the middle of the month. Daily maximum temperatures exceeded 40°C at inland Perth sites on the 12th, with the highest temperature of 42.0°C in the metropolitan area being recorded at Medina Research Centre. The 41.0°C recorded at Perth Metro was the ninth hottest March day since records commenced in 1897. Daily maxima across the Perth area ranged from 42.0°C at Medina Research Centre on the 12th to 21.6°C at Garden Island on the 28th.

Perth Metro's mean daily maximum temperature in March 2010 was 30.2°C, which is near the average of 29.4°C, and was Perth Metro's hottest March since 2007. Daily maxima ranged from 41.0°C on the 12th, Perth Metro's hottest March day for three years since it's hottest ever March day on record of 42.4°C on 7th March 2007, to 23.2°C on the 27th.

Minimum temperature

Mean daily minimum temperatures for March 2010 were above average across the Perth metropolitan area, with most sites recording means 1 °C to 2 °C above normal. Daily minima across Perth in March ranged from 28.8 °C at Swanbourne on the 12th, to 10.0 °C at Bickley on the 5th and Pearce on the 31st.

Perth experienced an unusually hot March night on the 12th as minima at most sites exceeded 25 °C and many metropolitan sites broke March records (see records below). Swanbourne's 28.8 °C was the hottest March night in its 16 years of record, and the highest minimum recorded in Perth on the 12th, whilst Perth Metro's 28.1 °C was the second hottest March night on its 113 years of record.

Perth Metro's mean minimum temperature in March was 18.1 °C, well above the long-term average of 16.4 °C, and Perth's warmest March in terms of minimum temperatures since a mean of 18.4 °C was recorded in 2005. Daily minima ranged from the uncomfortable 28.1°C on the 12th to 13.1°C on the 20th.

Wind

Inland sites as well as the coastal plain experienced more frequent and stronger north-easterly winds in the morning, whilst afternoon sea breezes were close to normal. The daily highest wind gust of 120 km/h was recorded at Ocean Reef on the 22nd, when the severe storms swept through the metropolitan area.

Other Phenomena

Perth recorded sunshine of 9.0 hours, compared to the long-term average of 9.5 hours.

Further information

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Extremes in 1 March to 31 March 2010
Hottest day 42.0 °C at Medina Research Centre on the 12th
Warmest days on average 31.7°C at Pearce RAAF
Coolest days on average 26.4°C at Rottnest Island
Coldest day 21.6 °C at Garden Island HSF on the 28th
Coldest night 10.0 °C at Bickley on the 5th
10.0 °C at Pearce RAAF on the 31st
Coolest nights on average 15.8 °C at Bickley
Warmest nights on average 19.5 °C at Rottnest Island
Warmest night 28.8 °C at Swanbourne on the 12th
Wettest overall 69.0 mm at Wanneroo (DAFWA)
57.8 mm at Jarrahdale
Wettest day 66.8 mm at Wanneroo (DAFWA) on the 23rd
57.2 mm at Jarrahdale on the 23rd
Highest wind gust 120 km/h at Ocean Reef on the 22nd

Record highest March daily rainfall
Highest daily rainfall
in March 2010 (mm)
Previous highest
for March
Years of
record
Perth Airport 42.2 on the 23rd 34.2 on the 28th in 2005 66
Gosnells City 53.0 on the 23rd 36.0 on the 28th in 2005 48




Record highest March mean daily maximum temperature
Mean daily maximum
temperature
for March 2010 (°C)
Previous highest
for March
Years of
record
Average for
March
Swanbourne 30.0 29.7 in 2005 16 28.8




Record highest March daily minimum temperature
Highest daily minimum
temperature
in March 2010 (°C)
Previous highest
for March
Years of
record
Average for
March
Perth Airport 28.6 on the 12th 26.2 on the 9th in 1996 66 15.8
Pearce RAAF 28.1 on the 12th 28.0 on the 8th in 2007 43 16.0
Medina Research Centre 27.7 on the 12th 25.5 on the 9th in 2000 27 15.9
Jandakot Aero 27.9 on the 12th 25.3 on the 6th in 1990 20 15.2
Swanbourne 28.8 on the 12th 26.7 on the 8th in 2007 16 17.4
Bickley 24.3 on the 12th 24.0 on the 9th in 2000 16 14.6



Summary statistics for March 2010
Maximum temperatures
for March
(°C)
Minimum temperatures
for March
(°C)
Rainfall
for March
(millimetres)
Mean for
March
2010
Diff
from
average
Highest for
March
2010
Mean for
March
2010
Diff
from
average
Lowest for
March
2010
Total for
March
2010
Average
for
March
Rank of
March
2010
Fraction of
March
average
Bickley 28.4 +0.4 38.5 1st 15.8 +1.4 10.0 5th 33.6 25.2 high 133%
Champion Lakes 30.1   39.1 12th 18.6   12.4 5th 41.0
Garden Island HSF 27.7 +0.6 38.8 12th 18.9 +0.9 14.9 5th 22.8 15.0 high 152%
Gosnells City 31.4 +1.1 41.5 12th 18.4 +1.4 12.3 5th 53.2 15.9 v high 335%
Jandakot Aero 30.9 +1.4 40.8 12th 16.7 +1.5 10.3 20th 36.6 15.7 high 233%
Medina Research Centre 30.6 +1.4 42.0 12th 17.8 +2.1 11.0 5th 27.8 19.7 high 141%
Pearce RAAF 31.7 +1.3 41.2 12th 17.3 +1.4 10.0 31st 15.0 14.8 average 101%
Perth Airport 31.1 +1.5 41.1 12th 17.4 +1.6 11.6 18th 42.2 16.2 high 260%
Perth Metro 30.2 +0.7 41.0 12th 18.1 +1.7 13.1 20th 40.4 19.4 high 208%
Rottnest Island 26.4 +0.5 37.5 11th 19.5 +1.0 15.1 5th 11.4 17.6 average 65%
Swanbourne 30.0 +1.2 39.8 12th 18.3 +1.1 12.5 5th 48.4 22.4 high 216%

Daily rainfall

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.

Central Coast (09)12345678910111213141516171819202122232425262728293031
Bickley - - - - - - - - - - - - - - - - - - - - - 0.4 30.6 2.6 - - - - - - -
Champion Lakes - - - - - - - - - - - - - - - - - - - - - 0.2 40.8 - - - - - - - -
Garden Island HSF - - - - - - - - - - - - - - - - 0.2 - - - - 5.2 17.4 - - - - - - - -
Gosnells City - - - - - - - - - - - - - - - - - - - - - - 53.0 0.2 - - - - - - -
Jandakot Aero - - - - - - - - - - - - - - - - - - - - - - 36.6 - - - - - - - -
Jarrahdale - - - - - - - - - - - - - - - - - - - - - 0.2 57.2 0.2 - - - - - 0.2 -
Medina Research Centre - - - - - - - - - - - - - - - - - - - - - 0.3 27.5 - - - - - - - -
Mundaring




















0.8 19.2 2.2






Pearce RAAF - - - - - - - - - - - -
- - - - - - - - - 11.8 3.2 -
- - - - -
Perth Airport - - - - - - - - - - - - - - - - - - - - - - 42.2 - - - - - - - -
Perth Metro - - - - - - - - - - - - - - - - - - - - - - 40.2 0.2 - - - - - - -
Rottnest Island - - - - - - - - - - - - - - - - - - - - - - 11.4 - - - - - - - -
Serpentine - - - - - - - - - - - - - - - - - - - - - - 11.4
- - - - - - -
Swanbourne - - - - - - - - - - - - - - - - - - - - - - 48.4 - - - - - - - -

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 1 pm on Wednesday 31 March 2010. 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 5 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.

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 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