Tuesday, 1 December 2009 - Monthly Climate Summary for Perth - Product Code: IDCKGC11LO
Above average rainfall for November in Perth
November Rainfall - above average The city received
38.2 mm of rainfall over 4 days in November, compared with the average
of 22 mm on about 6 days. This was the first time Perth has exceeded its
average monthly rainfall, for any month, since November 2008. The wettest
day in November was 22.4 mm on the 19th, which was the wettest November
day for 7 years, since the 22.8 mm on the 1st November 2002. Historically,
November rainfall has ranged from nil in 1891 to 73.2 mm in 1984. Last
November Perth recorded 57.8 mm on 13 days.
Year to date rainfall - very much below average: The total rainfall
for the 11-month period, January-November 2009, was 608.2 mm on 108 days,
which was the driest January to November since 2006, then 461.6 mm. The
average for the January to November period is 841 mm on about 108 days.
The total rainfall for the same period last year was 796.2 mm on 110 days
Mean daily maximum temperature - near average: Perth's
mean daily maximum temperature in November was 26.5°C, compared with the
average of 26.2°C. Daily maxima ranged from a mild 20.2°C on the 19th
to a hot 35.8°C on the 24th. Last November Perth recorded it's coldest
November since 1991 with a mean daily maximum temperature of 23.6°C.
January to November mean daily maximum temperature - equal second
highest on record: Perth's mean daily maximum temperature for the
January to November period was 24.5°C, which was the equal second
highest mean daily maximum temperature on record, along with 1988. The
average for the January to November period is 24.0°C. The highest
mean daily maximum temperature recorded for January to November in Perth
was 24.8°C in 1978.
Mean daily minimum temperature - near average: Perth's
mean daily minimum temperature in November was 13.8°C, compared with the
average of 14.1°C. Daily minima ranged from a cool 8.6°C on the 27th, to
a warm 20.2°C on the 12th.
* Denotes the highest daily maximum temperature recorded on 24 November 1913 and 11 November 2003.
Climate of Perth in December
December is typically a dry month and days are generally sunny and warm to hot. On most afternoons a sea breeze moderates the temperature. December is Perth's sunniest month on average with 11.6 hours of sunshine per day.
Very hot days: Perth can expect one day in December when the maximum temperature is 40°C or higher. The highest number of such December days was two in 1968, 1974, 1977, 1997, 2002 and 2007. The last time Perth recorded a very hot day in December was on 26 December 2007 with 44.2°C.
Hot days: On average, Perth can expect seven days in December when the maximum temperature is 32°C or higher. The highest number of hot days in December was eighteen in 1931, Perth's warmest December on record with a mean maximum temperature of 31.7°C. Last December, Perth recorded 5 hot days.
Note: 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.