Sydney in autumn 2017: a warm, wet start and a dry finish

Rainfall was above average for Sydney during autumn, with a very wet March followed by dry conditions in April and May. Nights were warmer than average, particularly during March, with some cooler conditions towards the end of the season.

A wet start with a dry finish

  • Rainfall was above average across the Sydney region during autumn, although generally lower than autumn 2015
  • Sydney experienced its wettest March since 1975 but a dry April and May, the driest April-May period since 2006
  • There were 42 rain days during the season, close to the historical average of 39 days
  • Eight days had at least 25 mm of rain, twice the historical average, with all but one occurring during March
  • Sunshine was close to average at Sydney Airport, with a cloudy March but a sunny end to the season

A warm autumn with some very warm nights

  • Minimum temperatures were above average across the Sydney region during autumn, with the warmest March nights on record
  • Maximum temperatures were above average at Observatory Hill, and close to average elsewhere in Sydney
  • The mean temperature at Observatory Hill was 1.2 °C above average, but cooler than the record warm autumn of 2016
  • 16 nights reached at least 20 °C, the third-highest number on record (the average is five nights)
  • Nights were very warm in late March, with some stations recording their warmest autumn night on record
  • Only seven days failed to reach 20 °C at Observatory Hill, the equal fourth-fewest on record (the average is 25 cool days)
  • There were some cooler nights during the second half of the season, including the coolest April nights since 2008
  • The minimum temperature at Observatory Hill dropped to 7.1 °C on 30 May, the coolest autumn night since 1999

Further information

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Extremes in autumn 2017
Hottest day 35.2 °C at Richmond RAAF on 29 Mar
Warmest days on average 24.1 °C at Penrith Lakes AWS
24.1 °C at Richmond RAAF
Coolest days on average 21.7 °C at Springwood (Valley Heights)
21.7 °C at Terrey Hills AWS
Coldest day 14.1 °C at Terrey Hills AWS on 31 May
Coldest night -0.9 °C at Camden Airport AWS on 30 May
Coolest nights on average 11.6 °C at Camden Airport AWS
Warmest nights on average 15.7 °C at Sydney (Observatory Hill)
Warmest night 23.7 °C at Sydney (Observatory Hill) on 20 Mar
23.7 °C at Sydney Airport AMO on 30 Mar
Warmest on average overall 19.6 °C at Sydney (Observatory Hill)
19.6 °C at Sydney Airport AMO
Coolest on average overall 17.3 °C at Springwood (Valley Heights)
Wettest overall 495.8 mm at Springwood (Valley Heights)
Driest overall 230.0 mm at Milperra Bridge (Georges River)
Wettest day 84.4 mm at Duffys Forest (Namba Rd) on 18 Mar
Strongest wind gust 91 km/h at Kurnell AWS on 9 Apr
91 km/h at Sydney Airport AMO on 9 Apr

Highest autumn total rainfall for at least 20 years

Observed
(mm)
Most recent
higher
Average for
autumn
Springwood (Valley Heights) 495.8 519.4 in 1990* 288.6

* note: there are gaps in the historical record at this site, so it is possible a higher value has gone unreported


Record highest autumn daily minimum temperature

New record
(°C)
Old
record
Years of
record
Average for
autumn
Sydney Airport AMO 23.7 on 30 Mar 23.4 on 4 Mar 2016 79 14.3
Camden Airport AWS 22.4 on 21 Mar 22.0 on 19 Mar 2000 41 11.0
Richmond RAAF 22.9 on 30 Mar 22.7 on 11 Mar 2016 23 11.6

Summary statistics for autumn 2017

Maximum temperatures
(°C)
Minimum temperatures
(°C)
Rainfall
(millimetres)
Mean for
autumn
2017
Diff
from
average
Highest for
autumn
2017
Mean for
autumn
2017
Diff
from
average
Lowest for
autumn
2017
Total for
autumn
2017
Average
for
autumn
Rank of
autumn
2017
Fraction of
autumn
average
Badgerys Creek AWS 23.5 -0.3 33.4 29 Mar 12.3 +0.9 -0.1 30 May 328.6 177.2 high 185%
Bankstown Airport AWS 23.9 +0.4 33.1 29 Mar 13.5 +0.7 2.2 30 May 281.8 251.7 average 112%
Camden Airport AWS 23.3 -0.5 31.5 12 Mar 11.6 +0.6 -0.9 30 May 282.0 212.3 high 133%
Campbelltown (Mount Annan) 23.5 -0.5 32.3 29 Mar 11.9 +0.7 0.0 30 May 263.2 193.0 high 136%
Canterbury Racecourse AWS 23.4 +0.1 32.2 22 Mar 13.4 +0.6 2.2 30 May



Holsworthy Aerodrome AWS 23.3   32.6 29 Mar 12.3   0.8 30 May 324.0


Horsley Park Equestrian Centre AWS 23.4 -0.3 33.5 29 Mar 13.3 +0.7 1.9 30 May 304.2 202.0 high 151%
Parramatta North (Masons Drive) 23.6 0.0 34.5 29 Mar 13.0 +0.1 2.0 30 May 369.0 271.7 high 136%
Penrith Lakes AWS 24.1 -0.3 33.7 29 Mar 13.6 +0.5 2.4 30 May 269.8 164.2 high 164%
Prospect Reservoir 23.7 +0.2 34.6 29 Mar 13.6 +0.6 2.6 30 May 406.1 244.5 high 166%
Richmond RAAF 24.1 +0.2 35.2 29 Mar 12.5 +0.9 -0.4 30 May 326.4 185.1 v high 176%
Springwood (Valley Heights) 21.7 -0.5 30.2 29 Mar 12.8 +0.5 4.0 30 May 495.8 288.6 high 172%
Sydney (Observatory Hill) 23.5 +1.3 31.9 22 Mar 15.7 +1.1 7.1 30 May 439.2 378.0 average 116%
Sydney Airport AMO 23.5 +0.7 31.9 22 Mar 15.6 +1.3 6.8 30 May 358.4 322.8 average 111%
Terrey Hills AWS 21.7 -0.4 30.2 29 Mar 14.1 +0.3 2.9 30 May 397.8 315.8 average 126%

Notes

The Seasonal climate summary, generally published on the first working day of each month, lists 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. More extensive discussion of significant weather events, along with later information and data that has had greater opportunity for quality control, will be presented in the Monthly Weather Review.

This statement has been prepared based on information available at 9 am on Thursday 1 June 2017. Some checks have been made on the data, but it is possible that results will change as new information becomes available.

In some situations, some or all of the rainfall is in the form of hail or snow. In these cases the totals given are for the water equivalent: the depth of liquid water that results from melting any frozen precipitation. There can be significant 'undercatch' of snow in strong winds, meaning the true precipitation can be higher than that reported.

Averages for individual sites 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.

Where temperature area averages are mentioned, they are derived from the ACORN-SAT dataset.

Further information

Media
(03) 9669 4057
Enquiries