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Friday 1 September, 2006
MONTHLY CLIMATE SUMMARY
- WESTERN AUSTRALIA REGIONAL OFFICE
Driest year to date on record for Perth
Year to date rainfall - record low: The total rainfall
for January to August this year was 340.4 mm recorded on 63 days making
it the driest such period on record. The previous record low was 361.7
mm on 65 days in 1940. The average is 690 mm.
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Perth's top 10 driest years to date
(January to August total)
|
|
Season
|
Rainfall (mm)
|
Rain Days
|
Ranking
|
|
2006
|
340.4
|
63
|
1
|
|
1940
|
361.7
|
65
|
2
|
|
1914
|
405.6
|
74
|
3
|
|
1894
|
437.6
|
69
|
4
|
|
1979
|
455.8
|
75
|
5
|
|
1977
|
474.4
|
68
|
6
|
|
1912
|
479.5
|
71
|
7
|
|
1877
|
480.4
|
83
|
8
|
|
1959
|
483.4
|
83
|
9
|
|
1971
|
488.7
|
77
|
10
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August Rainfall - below average: The city received 124.8
mm of rainfall over 17 days in August compared with the average of 135
mm over 16 days. The wettest day in August 2006 was the 15th when 27.0
mm was recorded. Last August Perth registered 124.6 mm on 12 days.
Mean daily maximum temperature - well above average:
Perth's mean daily maximum temperature in August was 20.2°C making
it the second highest mean maximum temperature for August on record. The
warmest August was 20.3°C in 1902 with the average for August being
18.5°C. Daily maxima ranged from a cool 16.0°C on the 16th to
a warm 26.7°C on the 29th.
Mean daily minimum temperature - above average: Perth's
mean daily minimum temperature in August was 9.7°C, compared with
the average of 8.1°C. Daily minima ranged from a cold 3.1°C on
the 17th to a warm 17.0°C on the 7th, the highest daily minimum temperature
on record for August for Perth. The previous record minimum was 16.6°C
on 13 August 1976.
| August monthly mean temperature and sunshine |
| Element |
2006
|
Long- term Average |
Highest
|
Year |
Lowest
|
Year |
Records Commence |
Maximum
Temperature (°C) |
20.1
|
18.5
|
20.3
|
1902
|
16.3
|
1932
|
1897
|
Minimum
Temperature (°C) |
9.7
|
8.1
|
11.5
|
1977/1983
|
6.9
|
1956/2001
|
1897
|
Sunshine #
(hours per day)
|
6.9
|
7.1
|
8.4
|
1902
|
4.2
|
1945
|
1898
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| August rainfall and rain days |
| Element |
2006 |
Long-term Average |
Highest |
Year |
Lowest |
Year |
Records Commence |
|
Rainfall (mm)
|
124.8
|
135
|
318.3
|
1945
|
11.8
|
1902
|
1876
|
|
Rain days
|
17
|
16
|
29
|
1955
|
4
|
1902/1978
|
1876
|
# This is a preliminary figure based on the available data at the time
of issue of this summary. Please check updated mean sunshine hours from
Daily Weather
Observations for Perth in early September.
| August daily extremes |
| Element |
2006 |
Date |
Extreme |
Date |
Records Commence
|
|
Highest daily maximum (°C)
|
26.7
|
29/08/2006
|
27.8
|
21/08/1940
|
1897
|
|
Lowest daily maximum (°C)
|
16.0
|
16/08/2006
|
9.9
|
05/08/1951
|
1897
|
|
Highest daily minimum (°C)
|
17.0
|
07/08/2006
|
16.6
|
13/08/1976
|
1897
|
|
Lowest daily minimum (°C)
|
3.1
|
17/08/2006
|
1.3
|
21/08/2000
|
1897
|
|
Wettest 24 hours to 9am (mm)
|
27.0
|
15/08/2006
|
73.9
|
14/08/1945
|
1876
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Climate of Perth in September
September is the first month of spring and in Perth a warm drying trend
is often experienced. Monthly rainfall and the number of wet days generally
decreases, whilst maximum and minimum temperatures and the number of sunshine
hours increases.
| September monthly mean temperatures and sunshine |
| Element |
Average |
Highest |
Year |
Lowest |
Year |
Records
Commence
|
Maximum temperature
(°C) |
20.0
|
22.6
|
1987
|
16.8
|
1915
|
1897
|
Minimum temperature
(°C) |
9.4
|
12.4
|
1988
|
8.0
|
2004
|
1897
|
|
Sunshine
(hours per day)
|
7.7
|
8.8
|
Many
|
4.9
|
1907
|
1898
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| September rainfall and rain days |
|
Element
|
Average
|
Highest
|
Year
|
Lowest
|
Year
|
Records Commence
|
| Rainfall (mm) |
81
|
199.1
|
1923
|
8.7
|
1916
|
1876
|
| Rain days |
15
|
26
|
1915
|
4
|
1877
|
1876
|
|
September daily extremes
|
|
Element
|
Highest
|
Date
|
Lowest
|
Date
|
Records Commence
|
|
Maximum temperature (°C)
|
32.7
|
30/09/1918
|
11.4
|
17/09/1917
|
1897
|
|
Minimum temperature (°C)
|
19.5
|
08/09/1916
|
1.5
|
* Twice
|
1897
|
|
Rainfall 24 hours to 9am (mm)
|
51.8
|
14/09/1984
|
n/a
|
n/a
|
1876
|
* Denotes the lowest minimum temperature for September on record on the
following dates: 1 and 10 September 2005.
Warm days in September: On average, Perth can expect two days
when the maximum temperature is 25°C or higher. The record is 10 days
in Perth's warmest September on record, 1987, when the mean maximum temperature
was 22.6°C.
Cold days in September: On average, Perth can expect approximately
one day every five years when the maximum temperature is 15°C or lower.
The record is four days in 1903 whilst there were no such days in 2005.
Cold nights in September: On average, Perth can expect three nights
each September when the minimum is 5°C or lower. The record is seven
nights in 2004 and there were three such nights in 2005.
Earliest 32-degree day of the season (hot day): The earliest 32-degree
maximum temperature of the season was on 18 September 1988, when 32.3°C
was recorded, the second highest maximum temperature for September on
record.
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September top 10 hottest days
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September top 10 coldest days
|
|
Position
|
Date
|
Max temp
(°C)
|
Position
|
Date
|
Max temp
(°C)
|
|
1
|
30 September 1918
|
32.7
|
1
|
17 September 1917
|
11.4
|
|
2
|
18 September 1988
|
32.3
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2
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04 September 1931
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11.6
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|
3
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22 September 1961
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32.2
|
3
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01 September 1931
|
12.1
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|
4
|
26 September 1961
|
31.3
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4
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16 September 1937
|
12.5
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|
5
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14 September 1987
|
30.9
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5
|
14 September 1947
|
12.7
|
|
6
|
28 September 1990
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30.7
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6
|
17 September 1915
|
12.9
|
|
6
|
20 September 1994
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30.7
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6
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19 September 1923
|
12.9
|
|
8
|
12 September 1939
|
30.6
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6
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12 September 1950
|
12.9
|
| 8 |
21 September 1954
|
30.6
|
9 |
20 September 1904
|
13.0
|
|
8
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27 September 1954
|
30.6
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10
|
12 September 1916
|
13.1
|
|
-
|
-
|
-
|
10
|
10 September 1925
|
13.1
|
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September top 10 warmest nights
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September top 10 coldest nights
|
|
Position
|
Date
|
Min temp
(°C)
|
Position
|
Date
|
Min temp
(°C)
|
|
1
|
08 September 1916
|
19.5
|
1
|
01 September 2005
|
1.5
|
|
2
|
30 September 1918
|
18.9
|
1
|
10 September 2005
|
1.5
|
|
3
|
02 September 1959
|
18.3
|
3
|
11 September 2004
|
1.7
|
|
4
|
27 September 1936
|
17.8
|
4
|
23 September 1998
|
1.8
|
|
5
|
20 September 1930
|
17.7
|
5
|
16 September 2002
|
2.0
|
|
6
|
29 September 1900
|
17.6
|
6
|
03 September 1994
|
2.3
|
|
7
|
20 September 1985
|
17.5
|
7
|
06 September 1956
|
2.6
|
|
7
|
28 September 1985
|
17.5
|
8
|
04 September 1998
|
2.8
|
| 9 |
30 September 1898
|
17.4
|
9 |
08 September 1952
|
3.1
|
|
10
|
28 September 1930
|
17.2
|
9
|
05 September 1999
|
3.1
|
| 10 |
26 September 1936
|
17.2
|
- |
-
|
-
|
|
10
|
28 September 1998
|
17.2
|
-
|
-
|
-
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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) and Glenn Cook Western Australia Climate Services Centre
on, tel: (08) 9263 2222, office hours.
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