Sydney in winter 2012: Warm, windy winter for Sydney

  • Close to average rainfall across the city, but wettest June since 2007
  • Days reached 29.4 °C on August 23, warmest winter day since 1995
  • Two days with wind gusts above 100 km/hr, first time in winter since 1978

Wet June, but drier end to winter

Sydney Observatory Hill recorded 319.4 mm of rain during winter, close to the historical average of 310.6 mm, which fell over 33 rain days (average for winter).

Most of the rain fell during June, 244.2 mm, which was the wettest June in Sydney since 2007, a consequence of two East Coast Lows and a rain-bearing trough during the first half of the month. During the second ECL, daily falls reached 89.8 mm at Rose Bay on the 11th and 102.4 mm at Potts Hill on the 12th, with a 48-hour rainfall of 125.8 mm at Observatory Hill.

In comparison, both July and August recorded well below average rainfall in Sydney, the driest July-August period since 2009. While there were 17 days of rain (average 22), only two days reached 10 mm at Observatory Hill during this period, compared with 6 such days in June.

Warm days across the city

The average maximum temperature at Sydney Observatory Hill during winter was 18.4 °C, 1.4 °C above the historical average. Days were warmer than average across most of the city and throughout the season, with warmest conditions later in August when rainfall was low and skies clear.

Only seven days were 15 °C or cooler during the season (average 21), while 23 days recorded at least 20 °C (average 12). The warmest day was the 23rd of August, when temperatures reached 29.4 °C at Sydney Observatory Hill and 30 °C at Sydney Airport, in both cases the 4th warmest winter day on record.

The average minimum temperature at Sydney Observatory Hill was 9.3 °C, 0.5 °C above average, with temperatures slightly cooler than average in western Sydney but well above average at Sydney Airport. No nights fell below 5 °C during winter (average 3 nights), with the warmest night reaching 16.1 °C on August 23rd. In western Sydney, 13 nights dropped to 0 °C in Richmond, close to normal for winter (12 nights).

ECLs and fronts cause strong winds in the city

The prevailing wind direction at Sydney Airport was southerly, with 43% of 3pm winds SE-SW, normal for winter. There were 12 strong wind days during the winter, which is close to normal, with several significant wind events causing damage in the city. For more detail about individual events see the relevant Monthly Summary.

During an East Coast Low on 5-6 June, Sydney Airport recorded a maximum wind gust of 104 km/hr, reaching 117 km/hr at Port Botany. Mean winds remained above 50 km/hr for 15 hours, in addition to large waves and beach erosion.

Sydney also recorded very strong winds on the 10th and 11th of August, as a low pressure system developed offshore in the wake of a front. Gusts reached 106 km/hr at Sydney Airport and 115 km/hr at Port Botany, with wind speeds remaining above 50 km/hr for almost twelve hours, and 10-minute mean wind speeds as high as 80 km/hr.

Sydney Airport also recorded a wind gust of 89 km/hr during a thunderstorm on August 23rd, and gusts of up to 78 km/hr associated with a cold front on August 17th, causing further damage. The last time Sydney Airport had two days with wind gusts above 100 km/hr during winter was in 1978.

First thunderstorm at the airport since April

Sydney Airport recorded an average of 6.8 hours of sunshine, average for winter, with generally cloudy conditions during June and sunny during August. There was one thunderstorm at Sydney Airport on the 23rd of August, the first storm since April, with three storms anywhere in Sydney. Three fogs were reported at the airport, normal for winter, with a particularly heavy event on July 25th.

Further information

Media
(03) 9669 4057
Enquiries

Extremes in winter 2012
Hottest day 30.0 °C at Sydney Airport AMO on 23 Aug
Warmest days on average 18.5 °C at Richmond RAAF
Coolest days on average 16.5 °C at Springwood (Valley Heights)
16.5 °C at Terrey Hills AWS
Coldest day 10.7 °C at Springwood (Valley Heights) on 26 Jun
Coldest night -2.8 °C at Camden Airport AWS on 8 Aug
Coolest nights on average 3.5 °C at Camden Airport AWS
Warmest nights on average 9.3 °C at Sydney (Observatory Hill)
Warmest night 16.1 °C at Sydney (Observatory Hill) on 23 Aug
Warmest on average overall 13.9 °C at Sydney (Observatory Hill)
Coolest on average overall 10.7 °C at Camden Airport AWS
Wettest overall 381.8 mm at Randwick Bowling Club
Wettest day 102.4 mm at Potts Hill Reservoir on 12 Jun
Highest wind gust 117 km/h at Port Botany (Molineux Point AWS) on 5 Jun

Summary statistics for winter 2012
Maximum temperatures
for winter
(°C)
Minimum temperatures
for winter
(°C)
Rainfall
for winter
(millimetres)
Mean for
winter
2012
Diff
from
average
Highest for
winter
2012
Mean for
winter
2012
Diff
from
average
Lowest for
winter
2012
Total for
winter
2012
Average
for
winter
Rank of
winter
2012
Fraction of
winter
average
Badgerys Creek AWS 17.8   28.8 23 Aug 4.5   -1.1 8 Aug 107.2
Bankstown Airport AWS 18.3 +0.4 29.5 23 Aug 5.8 -0.2 0.6 4 Aug 163.6 168.7 average 97%
Camden Airport AWS 17.8 -0.2 29.3 23 Aug 3.5 -0.3 -2.8 8 Aug 110.4 142.9 average 77%
Campbelltown (Mount Annan) 17.9   28.9 23 Aug 4.1   -1.2 8 Aug 101.2
Canterbury Racecourse AWS 17.9   29.0 23 Aug 6.2   0.4 8 Aug 226.2
Holsworthy Control Range 17.8   28.9 23 Aug 4.9   -0.7 5 Aug 123.0
Horsley Park Equestrian Centre AWS 17.6   28.4 23 Aug 6.0   0.1 7 Aug 133.4
Liverpool (Michael Wenden Centre) 18.3   28.9 23 Aug 5.0   0.1 3 Jul 110.2
Parramatta North (Masons Drive) 17.9 -0.1 29.1 23 Aug 6.7 -0.2 2.3 2 Aug 208.8 188.2 average 111%
Penrith Lakes AWS 18.2   28.9 23 Aug 6.0   0.7 8 Aug 89.6
Prospect Reservoir     28.7 23 Aug 6.7 -0.1 1.7 8 Aug 146.7 182.0 average 81%
Richmond RAAF 18.5   29.4 23 Aug 4.1   -2.4 8 Aug 93.0
Riverview Observatory 18.0 +0.6 28.7 23 Aug     3.0 8 Aug 290.1 271.5 average 107%
Springwood (Valley Heights) 16.5   26.5 23 Aug 6.9   2.2 7 Aug 112.6 187.7 average 60%
Sydney (Observatory Hill) 18.4 +1.4 29.2 23 Aug 9.3 +0.5 5.6 8 Aug 319.4 310.7 average 103%
Sydney Airport AMO 18.3 +0.7 30.0 23 Aug 9.1 +1.2 5.4 20 Jul 264.2 267.3 average 99%
Terrey Hills AWS 16.5   27.9 23 Aug 8.1   3.4 24 Jun 237.8

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 8 am on Monday 3 September 2012. 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