Sydney in spring 2011: Equal 5th warmest spring nights on record

  • Above average rainfall, wettest spring since 2004.
  • Above average maximum temperatures.
  • Equal 5th warmest spring on record for minimum temperatures.

Rainfall

Sydney Observatory Hill recorded 257.4 mm of rainfall during spring, above the historical average of 230.1 mm and slightly wetter than Spring 2010 (256.8 mm), making it the wettest spring since 2004 (361 mm). Most of the rain fell during November, with closer to average falls during September and below average during October.

There were two particularly wet events during the season. The first, between the 25th and 26th of September, caused two-day totals of 53.8 mm at Observatory Hill and up to 112.2 mm at Turramurra, associated with moist easterly windflow. The second was associated with a low pressure trough towards the end of November, with daily falls of up to 38.8 mm at Observatory Hill and four-day totals as high as 152.6 mm at Berowra in northern Sydney. The wettest single day was at Cronulla on October 15, with isolated heavy rain causing falls of up to 78 mm, but little rain elswhere in Sydney.

Temperature

Maximum temperatures were above average in Sydney during spring, at 23 °C compared to the historical average of 21.9 °C, with slightly warmer than average days throughout the metropolitan region. Temperatures were generally warm during September and November, but closer to average in October associated with cloudy conditions. There were seven days above 30 °C during the season, above the historical average of 4.3 days and substantially more than Spring 2010 (2 days).

The average minimum temperature was 14.8 °C at Sydney Observatory Hill during spring, 1.9 °C above the historical average. This is the equal 5th warmest spring on record for minimum temperatures, and the warmest since spring 2009 (15.4 °C); Sydney has not recorded below average minimum temperatures in spring since 1974. Minimums were above average throughout the season, but particularly towards the end of spring, with the 3rd warmest November on record. This included the equal 5th warmest spring night on record, with 24.2 °C on November 10.

Wind

Winds were predominantly southerly to easterly during spring, with 80% of 3pm winds at Sydney Airport between S and NE, typical for spring. There were only 7 strong wind days during the season, below average for spring, with the highest wind gusts reaching 96 km/hr at Richmond RAAF associated with a southerly change on September 29.

Other phenomena

Sydney Airport recorded an average of 7 hours of sunshine during spring, slightly below the historical average of 7.4 hours, associated with cloudy conditions in October and November. There were three thunderstorms reported at the Airport, below the spring average of 8 storms, with 15 thunderstorms reported anywhere in the Metropolitan region.

Further information

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Extremes in spring 2011
Hottest day 38.7 °C at Penrith Lakes AWS on 14 Nov
Warmest days on average 25.0 °C at Penrith Lakes AWS
Coolest days on average 21.8 °C at Terrey Hills AWS
Coldest day 12.4 °C at Springwood (Valley Heights) on 25 Sep
Coldest night -0.6 °C at Camden Airport AWS on 13 Sep
Coolest nights on average 10.6 °C at Camden Airport AWS
10.6 °C at Campbelltown (Mount Annan)
Warmest nights on average 14.9 °C at Sydney (Observatory Hill)
Warmest night 24.2 °C at Sydney (Observatory Hill) on 10 Nov
Warmest on average overall 19.0 °C at Sydney (Observatory Hill)
19.0 °C at Sydney Airport AMO
Coolest on average overall 17.3 °C at Springwood (Valley Heights)
Wettest overall 396.0 mm at Avalon (Wollstonecraft Ave)
Wettest day 78.0 mm at Cronulla South Bowling Club on 15 Oct
Highest wind gust96 km/h at Richmond RAAF on 29 Sep

Summary statistics for spring 2011
Maximum temperatures
for spring
(°C)
Minimum temperatures
for spring
(°C)
Rainfall
for spring
(millimetres)
Mean for
spring
2011
Diff
from
average
Highest for
spring
2011
Mean for
spring
2011
Diff
from
average
Lowest for
spring
2011
Total for
spring
2011
Average
for
spring
Rank of
spring
2011
Fraction of
spring
average
Badgerys Creek AWS 24.2   37.2 14 Nov 11.1   1.2 13 Sep 250.6
Bankstown Airport AWS 23.9 +0.5 37.3 14 Nov 12.5 +0.9 4.3 13 Sep 238.6 185.2 average 129%
Camden Airport AWS 24.3 +0.3 37.2 14 Nov 10.6 +0.7 -0.6 13 Sep 254.0 184.2 high 138%
Campbelltown (Mount Annan) 24.1   37.4 14 Nov 10.6   0.6 13 Sep 220.4
Canterbury Racecourse AWS 23.2   36.6 14 Nov 12.5   3.6 13 Sep 251.0
Holsworthy Control Range 23.6   36.8 14 Nov 11.3   1.4 13 Sep 233.0
Horsley Park Equestrian Centre AWS 23.9   37.0 14 Nov 12.1   2.9 13 Sep 303.0
Parramatta North (Masons Drive) 23.8 +0.2 37.2 14 Nov 12.5 +0.7 5.3 10 Sep 276.2 210.4 high 131%
Penrith Lakes AWS 25.0   38.7 14 Nov 12.5   3.4 13 Sep 268.6
Prospect Reservoir 24.0 +0.6 37.0 14 Nov 12.4 +0.5 4.0 13 Sep 252.0 180.2 high 140%
Richmond RAAF 24.4   36.8 14 Nov 11.4   0.9 13 Sep 257.6
Riverview Observatory 23.0 +0.5 36.7 14 Nov 13.2 +1.3 5.2 13 Sep 255.7 218.4 average 117%
Springwood (Valley Heights) 22.8   35.7 14 Nov 11.8   5.0 13 Sep 341.0 227.8 high 150%
Sydney (Observatory Hill) 23.0 +1.1 37.2 14 Nov 14.9 +1.5 7.4 10 Sep 257.4 230.1 average 112%
Sydney Airport AMO 23.2 +0.9 37.9 14 Nov 14.8 +1.9 6.6 10 Sep 246.6 213.6 average 115%
Terrey Hills AWS 21.8   35.8 14 Nov 13.2   5.8 10 Sep 363.0

Notes

A Seasonal Climate Summary is prepared to list the main features of the weather in Sydney - Greater Sydney using the most timely and accurate information available on the date of publication; it will generally not be updated. Later information, including data that has had greater opportunity for quality control, will be presented in the Monthly Weather Review, usually published in the fourth week of the month.

This statement has been prepared based on information available at 10 am on Thursday 1 December 2011. 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 20 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

Media
(03) 9669 4057
Enquiries