Greater Sydney in autumn 2018: new autumn temperature records set for Sydney

Autumn 2018 was the warmest on record for most sites in Greater Sydney, beating the previous record set in 2016. Rainfall was well below average across the region and the driest autumn at Observatory Hill since 2006.

Drier than average

  • Rainfall was below average across Greater Sydney, with a particularly dry May to end the season
  • The wettest day for autumn occurred on 13 March, where most coastal sites recorded more than 50 mm of rain; Mona Vale Golf Club was the wettest site in Greater Sydney recording 112.8 mm to 9am, its wettest March day on record
  • Sydney Observatory Hill recorded a daily rainfall of 25 mm or greater on only one occasion, compared to the autumn average of 4 days; while nearly all sites in the west of Greater Sydney had zero days with 25 mm or more
  • Sydney Observatory Hill recorded rainfall on 24 days, compared to the autumn average of 39 days
  • Sydney Airport averaged 7.7 hours of sunshine per day in autumn, an hour more than the average of 6.7 hours per day

Record breaking warmth

  • Autumn 2018 was the warmest autumn on record in terms of mean maximum temperature for many of the sites across Greater Sydney, slightly eclipsing records set in autumn 2016
  • The warmest day across the region for autumn 2018 was 18 March, when Badgerys Creek had its highest autumn temperature on record with 40.0 °C; Sydney Airport, Holsworthy and Bankstown Airport also recorded maxima over 40 °C
  • April was particularly warm, with many new April temperature records being set; March and May also brought above average temperatures across Greater Sydney
  • Sydney Observatory Hill experienced maximum temperatures of 25 °C or more on 49 days this autumn, the most ever for autumn, and well above the autumn average of 20 days
  • Minimum temperatures were typically up to 1 °C warmer across the region, however Sydney Observatory Hill and Sydney Airport were 1.8 °C and 2.0 °C above average respectively
  • Norah Head in the north of the region recorded its highest autumn mean daily minimum temperature on record equal with 2016, with an average of 16.9 °C
  • With the combination of warm days and nights, many sites had their highest autumn mean temperature on record

Sydney (Observatory Hill)

  • Total rainfall for Sydney (Observatory Hill) was 165.2 mm, which is 44% of the long-term average of 376.7 mm and the driest autumn since 2006
  • The mean daily maximum temperature for Sydney (Observatory Hill) was 24.9 °C, which is 2.7 °C above the long-term average of 22.2 °C, and the warmest autumn in its 160 years of record. The warmest day was 38.4 °C on 18 Mar, and the coolest day was on 11 May when the temperature reached 16.5 °C
  • The mean daily minimum temperature for Sydney (Observatory Hill) was 16.4 °C, which is 1.8 °C above the long-term average of 14.6 °C. The coldest morning was 9.2 °C on 20 May, and the warmest morning was on 14 Apr when the minimum temperature was 23.2 °C

Further information

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Extremes in autumn 2018
Hottest day 40.5 °C at Sydney Airport AMO on 18 Mar
Warmest days on average 26.9 °C at Penrith Lakes AWS
Coolest days on average 19.3 °C at Mount Boyce AWS
Coldest day 7.2 °C at Mount Boyce AWS on 11 May
Coldest night -0.1 °C at Mount Boyce AWS on 11 May
Coolest nights on average 9.5 °C at Mount Boyce AWS
Warmest nights on average 17.4 °C at Sydney Harbour (Wedding Cake West)
Warmest night 23.2 °C at Sydney (Observatory Hill) on 14 Apr
Warmest on average overall 20.8 °C at Norah Head AWS
20.8 °C at Sydney (Observatory Hill Comparison)
Coolest on average overall 14.4 °C at Mount Boyce AWS
Wettest overall 261.8 mm at Katoomba (Murri St)
Driest overall 38.0 mm at Milperra Bridge (Georges River)
Wettest day 112.8 mm at Mona Vale Golf Club on 13 Mar
Strongest wind gust 107 km/h at Wattamolla AWS on 13 May



Record highest autumn temperature
New record
(°C)
Old
record
Years of
record
Average for
autumn
Badgerys Creek AWS 40.0 on 18 Mar = 40.0 on 13 Mar 1998 23 23.8



Record highest autumn mean daily maximum temperature
New record
(°C)
Old
record
Years of
record
Average for
autumn
Sydney (Observatory Hill) 24.9 24.8 in 2016 159 22.2
Sydney Airport AMO 25.1 = 25.1 in 2016 78 22.8
Bankstown Airport AWS 26.2 26.0 in 2016 49 23.5
Parramatta North (Masons Drive) 25.7 25.5 in 2016 48 23.6
Camden Airport AWS 26.1 26.0 in 2016 41 23.8
Norah Head AWS 24.6 24.4 in 2016 23 22.7
Canterbury Racecourse AWS 25.0 = 25.0 in 2016 22 23.3
Penrith Lakes AWS 26.9 26.7 in 2016 22 24.4



Record highest autumn mean daily minimum temperature
New record
(°C)
Old
record
Years of
record
Average for
autumn
Norah Head AWS 16.9 = 16.9 in 2016 23 16.0



Record highest autumn mean temperature
New record
(°C)
Old
record
Years of
record
Average for
autumn
Bankstown Airport AWS 20.0 19.8 in 2016 49 18.2
Parramatta North (Masons Drive) 19.7 = 19.7 in 2016 48 18.2
Norah Head AWS 20.8 20.7 in 2016 23 19.3
Richmond RAAF 19.5 = 19.5 in 2016 23 17.8
Canterbury Racecourse AWS 19.4 19.2 in 2016 22 18.1
Horsley Park Equestrian Centre AWS 19.7 = 19.7 in 2016 20 18.2



Summary statistics for autumn 2018
Maximum temperatures
(°C)
Minimum temperatures
(°C)
Rainfall
(millimetres)
Mean for
autumn
2018
Diff
from
average
Highest for
autumn
2018
Mean for
autumn
2018
Diff
from
average
Lowest for
autumn
2018
Total for
autumn
2018
Average
for
autumn
Rank of
autumn
2018
Fraction of
autumn
average
Badgerys Creek AWS 25.9 +2.1 40.0 18 Mar 12.4 +1.0 2.5 18 May 54.0 171.6 low 31%
Bankstown Airport AWS 26.2 +2.7 40.1 18 Mar 13.7 +0.9 4.4 20 May 63.0 247.9 v low 25%
Camden Airport AWS 26.1 +2.3 39.7 18 Mar 11.5 +0.5 0.4 20 May 59.2 209.4 v low 28%
Campbelltown (Mount Annan) 26.3 +2.3 39.7 18 Mar 12.0 +0.8 1.6 20 May 41.4 180.4 v low 23%
Canterbury Racecourse AWS 25.0 +1.7 38.9 18 Mar 13.8 +0.9 4.1 31 May
Cooranbong (Lake Macquarie AWS) 25.3   38.8 18 Mar 12.5   2.7 18 May 194.2
Gosford AWS 24.5   38.2 18 Mar 14.5   6.0 18 May 193.6
Holsworthy (Defence) 25.1   40.4 18 Mar 12.5   3.8 20 May 132.8
Holsworthy Aerodrome AWS 25.5   39.8 18 Mar 12.7   3.3 18 May 49.4
Horsley Park Equestrian Centre AWS 25.9 +2.2 39.2 18 Mar 13.5 +0.8 3.5 20 May 46.6 194.6 v low 24%
Katoomba (Murri St)     30.2 18 Mar 10.5 +1.7 0.8 11 May 261.8 389.2 average 67%
Mangrove Mountain AWS 24.0 +2.3 36.4 18 Mar 12.5 +0.4 3.6 20 May 178.6 303.3 low 59%
Mount Boyce AWS 19.3 +2.3 29.8 18 Mar 9.5 +0.8 -0.1 11 May 134.6 235.8 low 57%
Norah Head AWS 24.6 +1.9 37.1 18 Mar 16.9 +0.9 9.4 31 May 138.4 375.0 v low 37%
Parramatta North (Masons Drive) 25.7 +2.1 38.5 18 Mar 13.6 +0.7 5.2 20 May 109.1 268.6 low 41%
Penrith Lakes AWS 26.9 +2.5 38.8 18 Mar 13.6 +0.5 3.8 31 May 104.4 161.6 average 65%
Prospect Reservoir 25.7 +2.2 39.1 18 Mar 13.7 +0.7 4.4 20 May 85.9 243.3 low 35%
Richmond RAAF 26.5 +2.6 39.6 18 Mar 12.5 +0.9 0.3 20 May 54.6 179.7 low 30%
Springwood (Valley Heights) 24.0 +1.8 37.1 18 Mar 13.5 +1.1 5.2 20 May 136.2 287.4 low 47%
Sydney (Observatory Hill Comparison) 25.4   38.0 18 Mar 16.1   8.8 20 May 157.6
Sydney (Observatory Hill) 24.9 +2.7 38.4 18 Mar 16.4 +1.8 9.2 20 May 165.2 376.7 low 44%
Sydney Airport AMO 25.1 +2.3 40.5 18 Mar 16.3 +2.0 8.2 31 May 149.2 320.8 v low 47%
Sydney Harbour (Wedding Cake West) 22.9 +0.9 38.2 18 Mar 17.4 +0.9 10.4 11 May
Sydney Olympic Park AWS (Archery Centre) 25.5   38.5 18 Mar 14.4   5.5 31 May 108.4
Terrey Hills AWS 23.4 +1.3 37.1 18 Mar 14.7 +0.9 5.7 31 May 210.4 307.0 low 69%

Notes

The Seasonal climate summary, generally published on the first working day of each month, lists the main features of the weather in Greater 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.

In September 2017 this summary was broadened to include data from observing sites in or near the Greater Sydney “Greater Capital City Statistical Area” (GCCSA). The Australian Bureau of Statistics designed the GCCSAs to “include the population within the urban area of the city, as well as people who regularly socialise, shop or work within the city, and live in small towns and rural areas surrounding the city. It is important to note that GCCSAs do not define the built up edge of the city. They provide a stable definition for these cities and are designed for the output of a range of social and economic survey data.

This statement has been prepared based on information available at 10 am on Friday 1 June 2018. 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