Monday, 1 March 2010 - Monthly Climate Summary for Perth - Product code IDCKGC11L0
Perth in February 2010: a dry month
- Below to very much below average rainfall
- Near average mean maximum and minimum temperatures despite a heatwave at the end of the month
Rainfall over the Perth area during February 2010 was below to very much below average. While rainfall during February is generally low, less thunderstorm activity than is usually expected resulted in several stations reporting no rainfall for February 2010, including Perth Airport which continued its longest dry spell on record with 100 days to the end of February 2010 (The previous record was 83 days between 24th December 1947 to 15th March 1948).
Showers and drizzle were reported in the Perth region on the 7th, 10th and 20th, whilst showers and thunderstorms were reported on the 26th and 27th, as Medina Research Station recorded the highest daily total for the month with 3.8 mm on the 26th.
Perth Metro recorded 0.2 mm on 1 day during February 2010, the driest February since 2000. Perth Metro has recorded zero rainfall in February on seventeen occasions since records began in 1876. Perth Metro's 78 days without measurable rain came to an end on the 7th when 0.2 mm was recorded, which is the second longest day spell on record. The longest dry spell at Perth Metro is 83 days between 15 December 1974 and 7 March 1975.
Mean maximum temperatures for February 2010 were close to normal in western parts but were above average in eastern parts of the Perth metropolitan area. The hottest location in terms of mean daily maximum temperature was inland at Pearce with 34.2°C.
The month began with cooler than normal conditions, however ended with a significant stretch of hot weather as a strong high in the Bight combined with a trough near the west coast bringing hot easterly winds over the city. Heatwave conditions (three or more days over 35°C) persisted from the 24th to the 28th at many sites, with daily temperatures peaking in the low 40's on the 25th. Gosnells observed the highest maximum temperature with 43.0°C.
Perth Metro's mean daily maximum temperature in February 2010 was 31.7°C, which is near the average of 31.3°C, and daily maxima ranged from a a very hot 41.5°C on the 25th to a mild 24.2°C on the 6th.
Mean minimum temperatures for February 2010 were generally near average in the Perth metropolitan area. Overnight temperatures ranged from 7.8°C at Jandakot on the 3rd to 27.8°C at Champion Lakes on the 26th.
Swanbourne registered its highest daily minimum temperature for any month with 27.2°C on the 26th during the heatwave at the end of the month as most Perth site reported minima above 26°C.
Perth Metro's mean daily minimum temperature in February 2010 was 18.6°C, which is close to the average of 18.0°C, as minima ranged from a hot 26.7°C on the 26th to a cool 12.3°C on the 5th.
The sea breeze was a significant feature during the first three weeks of February 2010, with sites on the coastal plain receiving stronger and more consistent afternoon sea breezes than usual, which moderated daytime temperatures. The highest wind gust for the month of 87 km/h was reported at Rottnest Island in the sea breeze. This situation was reversed in the last week of the month as strong easterly winds, gusting up to 80km/h at Perth Airport and Champion Lakes on the 27th, kept the sea breeze at bay.
The Perth metropolitan area saw somewhat cloudier conditions than normal as Perth Airport recorded an average of 10.5 hours of sunshine per day during February compared to the long-term average of 11.0 hours.
|Extremes in February 2010|
|Hottest day||43.0 °C at Gosnells City on the 25th|
|Warmest days on average||34.2 °C at Pearce RAAF|
|Coolest days on average||27.2 °C at Rottnest Island|
|Coldest day|| 21.9 °C at Garden
Island on the 3rd
21.9 °C at Rottnest Island on the 3rd
|Coldest night||7.8 °C at Jandakot Aero on the 3rd|
|Coolest nights on average||16.6 °C at Bickley|
|Warmest nights on average||19.6 °C at Rottnest Island|
|Warmest night||27.8 °C at Champion Lakes on the 26th|
|Wettest overall||4.8 mm at Medina Research Centre|
|Wettest day||3.8 mm at Medina Research Centre on the 26th|
|Highest wind gust||87 km/h at Rottnest Island on the 2nd|
|Record highest February daily minimum temperature|
Highest daily minimum
in February 2010 (°C)
|Swanbourne||27.2||on the 26th||27.1||on the 26th in 1997||17||18.4|
|Summary statistics for February 2010|
|Medina Research Centre||31.8||+0.6||42.2||25th||18.1||+0.7||10.7||3rd||4.8||21.1||average||23%|
|Central Coast (09)||1||2||3||4||5||6||7||8||9||10||11||12||13||14||15||16||17||18||19||20||21||22||23||24||25||26||27||28|
|Medina Research Centre||-||-||-||-||-||-||0.8||-||-||0.2||-||-||-||-||-||-||-||-||-||-||-||-||-||-||-||3.8||-||-|
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.
The 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 8 pm on Monday 1 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
(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.