Product Code: IDCKGC11L0

Perth Monthly Climate Summary: December 2006

Warmer than normal December in Perth

December Rainfall - near average: The city received 5.2 mm of rainfall over 2 days in December compared with the average of 13 mm over 4 days. Last December Perth registered 5.0 mm on 5 days.

Mean daily maximum temperature - above average: Perth's mean daily maximum temperature in December was 30.4°C, making it the equal highest mean daily maximum temperature for December since 1999. The December average is 28.7°C whilst last year was a very cool 23.7°C. Daily maxima ranged from a mild 21.5°C on the 8th to a very hot 38.8°C on the 16th.

Mean daily minimum temperature - near average: Perth's mean daily minimum temperature in December was 16.4°C, making it the highest mean daily minimum temperature for December since 17.4°C in 2002. The December average is 16.2°C. Daily minima ranged from a cool 9.7°C on the 1st to a warm 22.4°C on the 19th.

December monthly mean temperature and sunshine
Element

2006

 Long- term Average

Highest

 Year

Lowest

 Year Records Commence
Maximum
Temperature (°C)
30.4
28.7
31.7
1931
23.7
2005
1897
Minimum
Temperature (°C)
16.4
16.2
19.6
1977
13.9
2005
1897
Sunshine
(hours per day)
11.8
11.7
12.6
2000
8.0
1925
1898
December rainfall and rain days
Element 2006 Long-term Average Highest Year Lowest Year Records Commence
Rainfall (mm)
5.2
13
80.7
1951
0.0
5 years
1876
Rain days
2
4
14
1913/1944
0
5 years
1876

December daily extremes
Element 2006 Date Extreme Date

Records Commence
Highest daily maximum (°C)
38.8
16/12/2006
42.3
31/12/1968
1897
Lowest daily maximum (°C)
21.5
08/12/2006
14.9
17/12/1952
1897
Highest daily minimum (°C)
22.4
19/12/2006
27.1
18/12/1979
1897
Lowest daily minimum (°C)
9.7
01/12/2006
8.4
02/12/2002
1897
Wettest 24 hours to 9am (mm)
4.6
08/12/2006
46.7
03/12/1951
1876

Climate of Perth in January

It is midsummer in Perth in January, and days are generally sunny and either warm or hot. The low humidity that generally occurs on days of high temperature makes conditions more tolerable. Sea-breezes that blow across the coastal plain on most afternoons moderate the temperature. Hot spells, usually of two or three days' duration, are commonly followed by cooler conditions for a similar period. On average, January is Perth's driest month with 9 mm of rain over two days.

January mean temperatures and sunshine
Element Average Highest Year Lowest Year

Records
Commence
Maximum temperature
(°C)
30.4
34.4
1962
26.3
1939
1897
Minimum temperature
(°C)
17.7
20.9
1978
15.6
3 years
1897

Sunshine
(hours per day)
11.6
12.6
1974
8.3
1920
1898
January and rain days
Element
Average
Highest
Year
Lowest
Year
Records Commence
Rainfall (mm)
9
139.0
2000
0.0
11 years
1876
Rain days
2
8
1916/1990
0
11 years
1876

January daily extremes
Element
Highest
Date
Lowest
Date
Records Commence
Maximum temperature (°C)
45.8
31/01/1991
19.7
19/01/1939
1897
Minimum temperature (°C)
27.8
21/01/1989
8.9
25/01/2001
1897
Rainfall 24 hours to 9am (mm)
104.0
22/01/2000
n/a
n/a
1876

Very hot days in January: On average, Perth can expect one day when the maximum temperature is 40 degrees or higher. The greatest number of such days in January was four in 1961, 1965 and 1968. The last time Perth recorded such a day in January was on 11 January 2004 when 40.5 degrees was recorded.

Hot days in January: On average, Perth can expect twelve days when the maximum temperature is 32 degrees or higher. The highest number of such days in January was 24 in 1962, when the record highest mean maximum temperature for January (34.4 degrees) was set.

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.

Further information:
John Relf (JR), or Glenn Cook tel: (08) 9263 2222 on weekdays.