New South Wales Monthly Climate Summary: September 2006
Warm days, dry west of the divide

Tuesday 3 October, 2006

In Brief

Main points:

  • 4th warmest September on record for statewide average maximum temperatures
  • 5th warmest September on record for statewide average mean temperatures
  • Coastal NSW recorded average and above average rainfall
  • Central/southern slopes of the Great Divide, southern border and northwest areas of the state received below to very much below average rainfall

September 2006

Temperatures:
Well above average temperatures were recorded throughout NSW, making it the 12th consecutive September with above average mean temperatures. The statewide average mean temperature (the average of the daily maximum and minimum temperature) was 15.5ºC, which was 1.7 degrees above the historical average1 of 13.8ºC, and the 5th warmest September on record (statewide averages calculated 1950−2006) (See Map 1). The previous warmest September was in 2001 (an average mean temperature of 15.7ºC).

The statewide average maximum day-time temperature was 2.75ºC above the historical average of 20.6ºC, making this the 4th warmest September on record. The previous highest average maximum temperature was recorded in 2000 (23.6ºC). Nearly all of NSW experienced above average maximum temperatures, with the exception of the northeast corner (See Map 2). Large areas in the southern inland parts recorded the highest maximum temperature on record. This distribution of above average temperatures were due to warmer easterly wind anomalies across the state during much of September. In addition, unseasonally warm conditions were experienced as a result of a series of intense low-pressure systems near Tasmania combined with high pressure systems in the Tasman sea, directing persistent warm to hot and dry N-NW winds over much of the state.

Nights were also mild, with a statewide average minimum temperature of 7.7ºC, which is 0.6ºC above the historical average of 7.1ºC. Below average minimum temperatures were recorded across parts of the Riverina, however, the remainder of the state experience average or above average minimum temperatures See Map 3).

Rainfall:
September rainfall was varied throughout the state. The central and southern slopes west of the Great Divide, the northwestern and the inland southern border regions recorded below average September rainfall. Additionally, there were areas in the northwest of the state, South West Slopes and parts of the Central Tablelands and Central Slopes that recorded very much below average rainfall. Some localised pockets in those regions also recorded the lowest September rainfall on record. This distribution of below average rainfall is a result of easterly wind anomalies across much of the state and a lack of rain bearing systems from the west. Although these conditions were not favourable for rainfall in inland districts of NSW, they were responsible for parts of the coast (north of about Kiama) receiving above average and very much above average rainfall totals for September (See Map 4). In particular, an intense low pressure system that developed off the central NSW coast resulted in significant falls along the coast and adjacent ranges north from the Illawarra from around the 6th to the 13th. The statewide average rainfall for September 2006 of 26.0 mm was below the average of 36.1 mm and the driest since 2003 (statewide average of 11.7 mm).

Extremes

Weather extremes during September 2006

Highest temperature
Hottest day
 36.5ºC Lightning Ridge on the 23rd
Highest mean daily maximum temperature
Warmest days on average
 27.5ºC Mungindi
Lowest mean daily maximum temperature
Coolest days on average
 5.4ºC Thredbo
Lowest daily maximum temperature
Coldest day
 −1.4ºC Thredbo on the 9th
Lowest temperature
Coldest night
 −9.6ºC Thredbo on the 25th
Lowest mean daily minimum temperature
Coldest nights on average
 −2.4ºC Charlotte Pass
Highest mean daily minimum temperature
Mildest nights on average
 15.1ºC Byron Bay
Highest daily minimum
Warmest night
 20.7ºC Scone on the 23rd
Highest total rainfall
Wettest overall
 273.4 mm Darkes Forest
Highest daily rainfall
Wettest day
 110.5 mm Forster-Tuncurry on the 10th

Records for September 2006

Record Lowest Total Rainfall for September

Total rainfall
for September 2006 (mm) 		Previous lowest
for September 		Years of
record
Tumut
14.0
15.2
in 1914
121
Gunning Rural Supplies
3.4
9.9
in 1932
119
Tibooburra Post Office
0.0
= 0.0
in 2003
119
Berridale
5.4
6.1
in 1968
59
Blowering Dam
0.0
19.8
in 1994
51
Yarrangobilly Caves
7.6
48.8
in 1994
42

 

Record Highest Total Rainfall for September

Total rainfall
for September 2006 (mm) 		Previous highest
for September 		Years of
record
Williamtown RAAF
160.0
155.1
in 1970
61
Cessnock
135.9
109.3
in 1978
41
Paterson
161.4
118.2
in 1970
38
Wollombi
139.0
106.4
in 1995
32

 

Record Highest Mean Maximum Temperature for September

Mean daily maximum
temperature
for September 2006 (°C) 		Previous highest
for September 		Years of
record
Wellington
24.0
23.9
in 1928
88
Burrinjuck Dam
20.9
19.3
in 2001
86
Bathurst Agricultural Station
20.4
19.9
in 1972
84
Katoomba
17.3
17.2
in 1928
73
Wagga Wagga AMO
21.6
20.6
in 1944
65
Yass
19.9
19.6
in 1914
58
Cowra Research Centre
21.7
21.0
in 1972
56
Wyalong Post Office
22.8
22.3
in 1972
48
Peak Hill Post Office
24.3
23.9
in 1972
41
Tumbarumba Post Office
18.2
17.3
in 2001
41
Cowra Airport Comparison
22.6
21.8
in 1972
40
Orange Airport Comparison
17.7
16.7
in 1972
39
Thredbo AWS
5.4
= 5.4
in 2001
39
Narrandera Golf Club
21.8
= 21.8
in 1999
37
Charlotte Pass
7.3
7.0
in 1998
35
Gulgong Post Office
23.0
22.6
in 1972
34
Orange Agricultural Institute
17.3
16.3
in 2000
31
Goulburn Tafe
18.4
18.2
in 1999
29
Albury Airport
20.6
19.8
in 2001
24
Tidbinbilla Nature Reserve
18.3
17.4
in 2001
21

 

Record Highest Temperature for September

Highest temperature
in September 2006 (°C) 		Previous highest
for September 		Years of
record
Hume Reservoir
28.4
on 19th
27.7
on 27th in 1987
74
Albury Airport
28.9
on 19th
28.4
on 27th in 1987
24
Nelson Bay
34.2
on 24th
32.2
on 23rd in 2003
21

 

Record Lowest Daily Maximum Temperature for September

Lowest daily maximum
temperature
in September 2006 (°C) 		Previous lowest
for September 		Years of
record
Kempsey
15.0
on 10th
15.6
on 24th in 1975
86

 

Record Highest Mean Daily Minimum Temperature for September

Mean daily minimum
temperature
for September 2006 (°C) 		Previous highest
for September 		Years of
record
Sydney
13.5
13.4
in 1998
148
Sydney Airport AMO
13.2
12.8
in 2001
67
Nelson Bay
13.9
13.7
in 2001
21

 

Record Highest Daily Minimum Temperature for September

Highest daily minimum
temperature
in September 2006 (°C) 		Previous highest
for September 		Years of
record
Taralga Post Office
13.0
on 20th
= 13.0
on 23rd in 2003
47
Nerriga Composite
14.0
on 20th
= 14.0
on 17th in 1996
35
Oberon
12.0
on 20th
= 12.0
on 24th in 1988
33

Summaries for September 2006

Summary statistics for September 2006

Maximum temperatures
for September
(°C)		 Minimum temperatures
for September
(°C)		 Rainfall
for September
(mm)
Mean for 2006
Difference from normal
Highest for 2006
Mean for 2006
Difference from normal
Lowest for 2006
Total for 2006
Normal total
Albury
20.3
+2.7
28.2
4.6
−1.3
−0.4
41

Armidale
18.2
+0.6
25.2
5.9
+1.2
1.0
40

Batemans Bay
21.5
+1.3
30.1
7.8
+0.4
2.2
34
89
Bathurst
20.4
+4.2
27.0
2.5
−0.9
−1.5
23
46
Bega
20.5
+0.9
29.5
6.3
+0.4
0.6
25

Bowral
18.9
+2.8
27.3
7.3
+2.4
2.6
57
58
Broken Hill
23.5
+2.5
31.4
10.8
+2.0
4.1
3
20
Byron Bay
21.0
−1.2
24.9
14.9
+0.6
11.9
74
65
Canberra
19.4
+3.3
25.0
3.9
+0.7
−1.1
18
53
Cobar
23.7
+2.0
31.2
10.1
+1.1
5.8
26
25
Coffs HarbourO
22.8
+0.9
30.3
12.5
+1.6
8.7
134
60
Cooma
17.8
+1.7
23.7
0.8
−0.4
−5.2
23
38
Deniliquin
21.5

30.7
6.1

−0.7
9

Dubbo
24.0
+3.5
31.1
6.2
−0.1
1.7
9

Gosford
23.0
+1.8
30.5
8.6
+1.0
5.6
195
69
Goulburn
18.8
+2.7
24.9
2.4
−0.9
−2.7
23

Grafton
25.1
+0.3
32.6
12.0
+1.8
7.5
52
34
Griffith
22.7
+3.1
31.0
6.1
+0.2
0.0
12
37
Inverell
22.1
+2.5
27.8
8.0
+1.1
1.8
32
47
Katoomba
17.3
+3.0
24.4
7.3
+2.0
1.2
108
72
Kempsey
23.9
−0.1
31.0
10.5
+1.7
8.0
103
55
Maitland
23.7

34.6
8.3

4.3
157

Moree
25.3
+0.9
33.8
9.7
+0.8
3.7
60

Mudgee
22.3
+3.3
30.1
4.1
−0.3
0.0
14

Newcastle
21.8
+1.7
32.5
13.0
+1.6
8.9
139
74
Orange
17.3
+3.5
22.6
4.8
+0.7
1.0
24
82
Parkes
23.5
+4.1
29.0
7.4
+0.1
1.5
11
42
Penrith
24.1
+1.0
33.4
9.7
+0.2
6.9
94

Port Macquarie
22.9
+0.4
31.6
10.6
+1.4
6.8
89

Richmond
23.4
+0.8
32.9
8.0
−0.1
2.9
151

Scone
23.4
+2.1
33.2
8.3
+0.4
3.6
30
39
Sydney
23.1
+3.2
33.6
13.5
+2.4
9.0
192
69
Tamworth
23.8
+2.5
32.0
6.6
+0.9
1.3
24

Taree
23.5

35.0
9.9

6.0
128

Wagga Wagga
21.6
+4.2
29.1
3.7
−1.5
−2.3
20
51
Wollongong
22.5
+2.2
33.2
10.7
+0.2
4.9
153
64
** Please note: the length of record for some of the stations listed in the above table is not long enough to produce valid temperature and/or rainfall averages

This statement has been prepared based on information available at 1 PM on 3 October 2006. Although every effort has been made to check them, it is possible that results may change as new information becomes available.

A note about deciles: Deciles are used to give an element (in this case rainfall or temperature) a ranking. Deciles are calculated by arranging the totals in ascending order (from lowest to highest) then splitting them into 10 equal groups (thus the groups are called deciles). The first group would be in decile range one, the second group in decile range two, etc up to the highest annual totals (highest 10 per cent) being in decile range 10.

1Averages: Averages are based on the period 1961 to 1990 which is a convention of the World Meteorological Organisation.

Further information: Contact Louise Tilley 9296 1555, email: reqnsw@bom.gov.au

A directory of Bureau services is available on poll fax: 1800 630 100

The latest rainfall and temperature maps are available here
Climate averages for New South Wales localities are available here
Daily Weather Observations for selected New South Wales localities are available here