Thursday, 31 March 2011 - Monthly Climate Summary for Perth - Product code IDCKGC21L0

Perth in March 2011: A hot and dry month

• 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.

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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.

Extremes Records Summaries Important notes the top

Extremes Records Summaries Important notes the top

Extremes Records Summaries Important notes the top

Extremes Records Summaries Important notes the top

Extremes Records Summaries Important notes the top

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.

Extremes Records Summaries Important notes the top