Monday, 1 December 2008 - Seasonal Climate Summary for Sydney - Greater Sydney - Product code IDCKGC25x0

Variable spring temperatures in Sydney and average rainfall

Summary

Sydney had a warm spring with close to average rainfall. Except for the Richmond area, both daytime and night-time temperatures were about 1°C above the historic averages. As is typical for spring, daily temperatures were quite variable with several hot days often followed by periods of cool to cold and wet weather.

An archive of previous seasonal summaries for Sydney - Greater Sydney is also available, as are summaries for other states and many other climate summaries and diagnostics.

Details

  • rainfall was close to average
  • warm days - average daytime temperatures about 1°C above the historical average
  • mild nights - average minimum temperature half to 1°C above historical average
  • slightly below average sunshine

Rainfall

The total spring rainfall of 239.0 mm at Sydney (Observatory Hill) was close to the historic spring average1 of 230 mm. The rain was fairly evenly distributed over the 3-month period. There were 39 rain days, which is above the historic average of 33 rain days. The highest spring rainfall totals were on Sydney's North Shore with Turramurra recording 308 mm for the season. The lowest totals were in western Sydney with Willmot recording only 123 mm for the season.

Most of Sydney's spring rainfall was associated with two east coast lows (on 5th September and 20th November) and several low pressure troughs (on 15th October, 15th and 29th November). Thunderstorms brought the majority of the rainfall during November.

Sydney's Warragamba Dam catchment area recorded quite variable spring rainfall totals ranging from 150 mm in the upper catchment to 250 mm in parts of the lower catchment. Katoomba, on the catchment divide, recorded a total of 334 mm during spring. Storage levels have fallen only slightly over the spring period. Recent rainfall and current levels in Sydney's water catchments can be found on the Sydney Catchment Authority web site http://www.sca.nsw.gov.au/dams/rainfall.html

Temperatures

The average maximum (daytime) temperature at Observatory Hill during spring was 22.7°C, which is 0.9°C above the historic average1 of 21.8°C. This falls in about the warmest 15% of all springs over the past 150 years of record. The western suburbs recorded spring temperatures closer to the historic average with Richmond and Penrith the only sites to record below average maximum temperatures.

Sydney's nights during the season were generally mild and above the historic average minimum temperature. The average minimum at Observatory Hill of 14.5°C was 1.1°C above the historic spring average1 of 13.4°C. This ranks as equal 9th warmest over the 150 year record. It is also the 16th consecutive spring with above average minimum temperatures at Observatory Hill. The mild overnight conditions along the coast was partly due to the moderating influence of the ocean and mild NE - NW winds, especially during September. The slightly higher than normal cloud cover over the season also contributed towards the mild nights.

The highest temperature at Sydney Observatory Hill during spring was 35.0°C on 31 October while the lowest temperature was 7.0°C on 10 September.  Corresponding extremes over the Greater Sydney area ranged from a high of 37.0°C at Sydney Airport on 31 October to a low of −0.3°C at Camden Airport AWS on 11 September.

Wind

There were 20 windy days* in coastal Sydney during spring, close to the historic average of 19 windy days. The prevailing coastal wind direction during spring afternoons was E-NE for 50% of the time compared to the normal 42% from this direction. The highest wind gust recorded in the Sydney region was 100 km/h at Wattamolla (Royal National Park) on the 6 September associated with an east coast low pressure system.

Other phenomena

There were 5 days on which thunderstorms were reported at the Sydney Observatory Hill site during spring which is below the historic average of 8 for the season. The most severe was on 29 November when 3cm hail was reported from several suburbs. There was a mix of clear sunny days and overcast days during spring associated with the periods of warmer and cooler temperatures. The average sunshine was 7.6 hours per day, slightly below the historic spring average of 7.8 hours per day.

Further information

NSW Climate Services Centre
NSW Regional Office
Bureau of Meteorology
Phone (02) 9296 1555
Email reqnsw@bom.gov.au

* Windy day defined as average wind speed of 40 km/hr or more over a 10 minute period.


Extremes

Hottest day
Highest temperature
37.0°C at Sydney Airport on 31 Oct
Warmest days on average
Highest mean daily maximum temperature
25.0°C at Penrith Lakes AWS
Coolest days on average
Lowest mean daily maximum temperature
21.9°C at Terrey Hills AWS
Coldest day
Lowest daily maximum temperature
11.6°C at Springwood on 5 Sep
Coldest night
Lowest temperature
−0.3°C at Camden Airport AWS on 11 Sep
Coolest nights on average
Lowest mean daily minimum temperature
10.1°C at Campbelltown (Mount Annan)
Warmest nights on average
Highest mean daily minimum temperature
14.5°C at Sydney (Observatory Hill)
Warmest night
Highest daily minimum temperature
22.5°C at Sydney (Observatory Hill) on 3 Oct
Wettest overall
Highest total rainfall
308.2 mm at Turramurra
Driest overall
Lowest total rainfall
123.0 mm at Willmot
Wettest day
Highest daily rainfall
84.6 mm at West Pymble on 6 Sep
Highest wind gust

100 km/h at Wattamolla (Royal N.P.) on the 6 Sep
87 km/h at Badgerys Creek AWS on 6 Oct


Records

Nil recorded


Summaries

This table is very wide and may not fit if printed.

Summary statistics for spring 2008
Maximum temperatures
for spring
(°C)
Minimum temperatures
for spring
(°C)
Rainfall
for spring
(millimetres)
Mean for
spring
2008
Diff
from
average
Highest for
spring
2008
Mean for
spring
2008
Diff
from
average
Lowest for
spring
2008
Total for
spring
2008
Average
for
spring
Rank of
spring
2008
Fraction of
spring
average
Sydney (Observatory Hill) 22.7 +0.9 35.0 31 Oct 14.5 +1.1 7.0 10 Sep 239.0 229.9 average 104%
Bankstown Airport AWS 24.1 +0.7 35.8 31 Oct 12.0 +0.5 3.1 11 Sep 166.0 182.6 average 91%
Camden Airport AWS 24.0 +0.1 35.9 14 Nov **   −0.3 11 Sep 173.0 182.2 average 95%
Liverpool 24.7 +1.2 35.8 31 Oct 11.2 0.0 1.4 11 Sep 182.8 184.4 average 99%
Parramatta North 23.9 +0.3 35.4 31 Oct 12.3 +0.6 4.2 2 Sep 228.5 206.2 average 111%
Penrith Lakes AWS 25.0 −0.2 36.5 14 Nov 12.3 +0.2 3.1 11 Sep 181.2 170.8 average 106%
Prospect Reservoir 24.4 +1.1 35.8 14 Nov 12.0 +0.1 3.1 10 Sep 176.5 179.8 average 98%
Richmond RAAF 23.8 −1.0 35.0 14 Nov 10.6 −0.4 0.5 2 Sep 178.0 198.3 low 90%
Springwood* 23.0   34.0 14 Nov 11.6   3.1 11 Sep 202.6 226.4 average 89%
Terrey Hills* AWS 21.9   34.9 31 Oct 12.9   5.3 10 Sep 261.4

* new stations, no historic average temperatures available and no historic average rainfall available for Terrey Hills

** missing data during September, no average minimum available


Notes

This statement has been prepared based on information available at 1 pm on Monday 1 December 2008. 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 10 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 decile ranking (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.

Further information

NSW Climate Services Centre
NSW Regional Office
Bureau of Meteorology
Phone (02) 9296 1555
Email reqnsw@bom.gov.au