Monday, 3 September 2007 - Seasonal Climate Summary for Sydney - Product code IDCKGC25L0

Third wettest winter on record in Sydney

Summary

  • 3rd wettest winter on record, total of 730 mm
  • wettest winter since 1950
  • slightly above average maximum and minimum temperatures
  • below average sunshine hours

Rainfall

The total winter rainfall of 730 mm at Sydney (Observatory Hill) was very much above the historic winter average1 of 309.7 mm. It is the wettest winter since 1950 when the record highest winter rainfall of 1060 mm was recorded. Most of this winter's rainfall fell during June (511 mm). There were 37 rain days, which is above the historic average of 32 rain days. The highest winter rainfall totals were along the coast while the far south-west recorded the lowest falls. Winter totals ranged from a high of 730 mm at Observatory Hill to a low of 267 mm at Campbelltown. Both Parramatta and Bankstown recorded their wettest winter on record.

Sydney's Warragamba Dam catchment received above average rainfall during winter. The catchment recorded winter totals of 200−300 mm which boosted the water supply levels significantly. Katoomba, on the catchment divide, recorded 562 mm during winter which is double the normal winter rainfall.

Some sites had their highest winter rainfall on record.

Temperature

Average maximum temperatures during winter were close to the historic average over most of Sydney during winter.  The average maximum (daytime) temperature at Observatory Hill was 17.9°C, which is above the historic winter average1 of 16.9°C. However, it is still the coolest August average maximum since 1998. The average maximum temperatures in western suburbs were slightly below normal for winter.

Average minimum (night-time) temperatures over Sydney were slightly above the historic winter average. The average minimum at Observatory Hill of 9.9°C was +0.8°C above the historic winter average1. Average minimum temperatures in the western suburbs were several degrees cooler than coastal suburbs but still above the normal winter average.

The highest temperature at Sydney Observatory Hill during winter was 27.7°C on 27 August, while the lowest temperature was 3.7°C on 17 July. Corresponding extremes across the Sydney metropolitan area ranged from a high of 27.9°C at at Penrith Lakes and Sydney Olympic Park on 27 August to a low of −3.5°C at Badgerys Creek on 17 July.

Some sites had their lowest winter temperature on record.

Wind

There were 20 windy days in coastal Sydney during winter, the highest since 1998 when 25 windy days.

Other phenomena

Average daily sunshine hours for winter in Sydney were 6.2 compared to the historic average of 6.8, reflecting the wetter than average conditions during the season. There were 4thunderstorms reported compared to an average of 3 per winter.

Further information

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

Extremes

Hottest day
Highest temperature
27.9°C at Penrith Lakes and Sydney Olympic Park on 27 Aug

Warmest days on average
Highest mean daily maximum temperature
18.0°C at Parramatta North (Masons Drive)
Coolest days on average
Lowest mean daily maximum temperature
16.2°C at Springwood Bowling Club
Coldest day
Lowest daily maximum temperature
10.8°C at Springwood Bowling Club on 27 Jun
Coldest night
Lowest temperature
−3.5°C at Badgerys Creek on 17 Jul
Coolest nights on average
Lowest mean daily minimum temperature
4.8°C at Camden Airport AWS
Warmest nights on average
Highest mean daily minimum temperature
9.9°C at Sydney (Observatory Hill)
Warmest night
Highest daily minimum temperature
17.0°C at Sydney (Observatory Hill) on 30 Aug
Wettest overall
Highest total rainfall
730.0 mm at Sydney (Observatory Hill)
Wettest day
Highest daily rainfall
126.0 mm at Riverview Observatory on 20 Aug
Highest wind gust
106 km/hr at Fort Denison on 8 Jun

Records

Record highest total winter rainfall
Total rainfall
for winter 2007 (mm)
Previous highest
for winter
Normal for
winter
Years of
record
Parramatta North (Masons Drive) 520.4 472.4 in 1986 188.7 42

Highest total winter rainfall for at least 20 years
Total rainfall
for winter 2007 (mm)
Most recent higher
for winter
Normal for
winter
Years of
record
Sydney (Observatory Hill) 730.0 1060.3 in 1950 311.1 57



Summaries

Summary statistics for winter 2007
Maximum temperatures
for winter
(°C)
Minimum temperatures
for winter
(°C)
Rainfall
for winter
(millimetres)
Mean for
winter
2007
Diff
from
normal
Highest for
winter
2007
Mean for
winter
2007
Diff
from
normal
Lowest for
winter
2007
Total for
winter
2007
Normal
for
winter
Rank of
winter
2007
Fraction of
winter
normal
Central Tablelands (S) (district 63)
Springwood Bowling Club 16.2 26.5 27 Aug 6.6 −2.6 17 Jul 408.5 190.6 very high 214%
Metropolitan (E) (district 66)
Parramatta North 18.0 −0.1 27.5 27 Aug 7.7 +0.9 0.0 17 Jul 520.4 188.7 highest 276%
Sydney 17.9 +0.2 27.7 27 Aug 9.9 +0.8 3.7 17 Jul 730.0 311.1 very high 235%
Terrey Hills AWS 16.5 25.8 28 Aug 8.4 0.2 17 Jul 520.0
Metropolitan (W) (district 67)
Richmond RAAF 17.4 27.2 27 Aug 5.3 −3.4 17 Jul 351.8
Illawarra (district 68)
Camden Airport AWS 17.6 −0.4 27.1 27 Aug 4.8 +1.1 −3.1 17 Jul 317.0 146.3 very high 217%
Additional climate data for Sydney (Observatory Hill) for winter 2007
 

Winter 2007

Normal for winter

Number of rain days

 37

 32

Average sunshine hours per day*

 6.2

 6.8

Average humidity at 3pm (%)

 55

 53

Number of thunderstorms

 4

 3

Number of windy days*

 20

 12


Notes

This statement has been prepared based on information available at 8 am on Monday 3 September 2007. Some checks have been made on the data, but it is possible that results will change as new information becomes available.

1Averages:  historic average temperatures for Observatory Hill and Richmond are based on the period 1961 to 1990 which is a convention of the World Meteorological Organisation.  Average temperatures for Parramatta are based on all available data, 1968 - 2006 and Camden 1972 - 2006.  Rainfall averages and extremes for Observatory Hill are based on all years of record 1859 - 2006.

Normals 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 20 years of record, as they cannot then be calculated reliably. For rainfall, it is sometimes better to use the median rather than the mean to indicate "normal" rain, but this has not been done here.

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, normal in decile 4 to 7, high in decile 8 or 9 and very high is in decile 10).
The Fraction of normal shows how much rain has fallen this time as a percentage of the long-term mean.

Further information

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