Sydney in autumn 2013: A warm autumn for Sydney

  • Equal-third-warmest autumn for mean maximum temperatures, fewest cold days on record
  • Most heavy rain days since 2003; driest autumn spell on record
  • Close to average minimum temperatures
  • Well above average sunshine, few cloudy days

Rainfall

Sydney Observatory Hill recorded 375.6 mm of rain during autumn, close to the historical average of 377.5 mm, with autumn totals close to normal across the city. The rain fell over 34 days, close to the autumn average of 39 days, of which eight recorded at least 25 mm (average 4 days), the most since 2003. This included a 3-day total of 107.2 mm to 9am on 5 April during a period of easterly flow, while East Coast Lows produced 64.8 mm between 2 am and 2 pm on 20 April and a 3-day total of 77.8 mm to 9am on 25 May.

Autumn also featured several dry, clear spells. Notably, only 0.2 mm of rain was recorded in the four weeks between 24 April and 22 May. This is the driest such period on record for autumn, although similar spells occurred in 2012 (0.4 mm from 26 April - 24 May) and 1973 (0.3 mm from 3 May - 1 June).

Temperature

Sydney Observatory Hill recorded an average maximum temperature of 23.9 °C during autumn, 1.7 °C above the historical average. This is the equal-third-warmest autumn on record and the warmest autumn since 2007; the last autumn with below average maximum temperatures at Sydney Observatory Hill was in 1972. Temperatures were above average across the city, associated with several clear, sunny spells and a lack of cold days.

Only six days had maximum temperatures below 20 °C during autumn, the fewest cold days on record (average 26 days); this is substantially fewer than the previous record of 9 days, set in 1958. There were also 35 days above 25 °C, the equal-fifth-highest frequency and almost double the average of 20 days, although only three days exceeded 30 °C (average 2 days). There were several notable mild spells including 2-28 March and 21 April - 16 May, while temperatures reached 33.5 °C on 28 March, the latest such warm day since 1986.

The average minimum temperature at Sydney Observatory Hill was 15.3 °C, 0.7 °C above the historical average, with slightly below average temperatures at sites in western Sydney. Nights were warmer than average during March but closer to normal in April and May; only four nights dropped below 10 °C during the season (average 9-10 nights) while 14 reached at least 20 °C, the most since 2007 (average 4-5 nights). The mean temperature during autumn was consequently 19.6 °C, 1.2 °C above the historical average.

Other phenomena

Sydney Airport recorded an average of 7.5 hours of bright sunshine during autumn, well above the historical average of 6.7 hours and the sunniest autumn since 2008. There were 22 cloudy days, well below the historical average of 34 days and the fewest since 22 days in 2008; the only other autumn so clear was in 1991 (21 cloudy days). Three thunderstorms were reported during the season, with heavy fog on 28 and 29 April.

The prevailing wind direction was southerly, with 49% of 3pm winds between SE and SW, close to normal for autumn, while 31% of 3pm winds were NNE-ENE. Only 11% of 3pm winds were between N and W, below average for autumn (15%). There were 15 strong wind days reported at the airport, with a maximum wind gust of 76 km/h on 19 April.

Further information

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Extremes in autumn 2013
Hottest day 34.9 °C at Sydney Airport AMO on 28 Mar
Warmest days on average 24.5 °C at Penrith Lakes AWS
Coolest days on average 22.2 °C at Springwood (Valley Heights)
Coldest day 13.1 °C at Springwood (Valley Heights) on 23 May
Coldest night -0.1 °C at Richmond RAAF on 19 May
Coolest nights on average 10.5 °C at Camden Airport AWS
Warmest nights on average 15.3 °C at Sydney (Observatory Hill)
Warmest night 21.6 °C at Sydney (Observatory Hill) on 23 Mar
Warmest on average overall 19.6 °C at Sydney (Observatory Hill)
Coolest on average overall 17.2 °C at Springwood (Valley Heights)
Wettest overall 409.0 mm at Sydney Botanic Gardens
Wettest day 101.0 mm at Cronulla South Bowling Club on 4 Apr
Highest wind gust 81 km/h at Port Botany (Molineux Point AWS) on 17 Mar
81 km/h at Kurnell AWS on 19 Apr

Summary statistics for autumn 2013
Maximum temperatures
for autumn
(°C)
Minimum temperatures
for autumn
(°C)
Rainfall
for autumn
(millimetres)
Mean for
autumn
2013
Diff
from
average
Highest for
autumn
2013
Mean for
autumn
2013
Diff
from
average
Lowest for
autumn
2013
Total for
autumn
2013
Average
for
autumn
Rank of
autumn
2013
Fraction of
autumn
average
Badgerys Creek AWS 23.9   33.2 24 Mar 11.3   2.3 15 May 192.8
Bankstown Airport AWS 24.2 +0.8 32.7 28 Mar 12.5 -0.3 3.9 15 May 183.4 253.4 average 72%
Camden Airport AWS 24.1 +0.4 32.0 28 Mar 10.5 -0.4 1.2 15 May 143.0 210.3 average 68%
Campbelltown (Mount Annan) 24.1   31.8 24 Mar 10.8   1.8 15 May 168.6
Canterbury Racecourse AWS 23.5   32.6 28 Mar 12.3   3.6 15 May
Holsworthy Aerodrome AWS 23.9   32.4 24 Mar 12.0   2.9 15 May 207.4
Holsworthy Control Range 23.7   32.0 24 Mar 11.4   1.9 15 May 190.6
Horsley Park Equestrian Centre AWS 23.8   31.8 28 Mar 12.2   2.4 19 May 172.2
Parramatta North (Masons Drive) 23.8 +0.3 32.2 27 Mar 12.2 -0.7 5.3 15 May 200.4 270.1 average 74%
Penrith Lakes AWS 24.5   33.5 28 Mar 12.6   3.9 20 May 154.8
Prospect Reservoir 24.1 +0.7 33.3 27 Mar 12.6 -0.4 3.8 19 May 188.0 242.3 average 78%
Richmond RAAF 24.3   32.6 28 Mar 11.1   -0.1 19 May 159.8
Springwood (Valley Heights) 22.2   31.6 24 Mar 12.1   5.0 19 May 214.2 288.2 average 74%
Sydney (Observatory Hill) 23.9 +1.7 33.5 28 Mar 15.3 +0.7 9.2 15 May 375.6 377.5 average 99%
Sydney Airport AMO 23.9 +1.2 34.9 28 Mar 15.1 +0.9 8.4 19 May 282.2 322.3 average 88%
Terrey Hills AWS 22.4   31.5 28 Mar 13.6   5.9 26 May 340.2

Notes

A Seasonal Climate Summary is prepared to list the main features of the weather in 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 Monday 3 June 2013. 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