Greater Sydney in 2018: warm and generally drier than normal

Greater Sydney was warmer than average during 2018 for both daytime and overnight temperatures. The annual mean maximum temperature at Observatory Hill was within the top five warmest years on record. Total rainfall across most sites was generally below average to average for the year.

The Australian annual climate statement provides a comprehensive summary of Australia's climate during 2018. Information about changes and long-term trends in Australia's climate can be found in State of the Climate 2018.

Below average to average rainfall, with some days of localised heavy rainfall

  • Rainfall across the two day period from 28 to 29 November resulted in many sites recording one of these days as their wettest day of the year across Greater Sydney
  • Above average rainfall was recorded during June, October, November and December, with most other months recording average or below average rainfall
  • Total rainfall for the year was below average at most sites

A warm year

  • On 7 January, four Greater Sydney sites recorded their hottest day on record
  • On the same day, Penrith recorded 47.3°C, the highest temperature observed in the Sydney region since 1939
  • During July and August, three sites had their lowest temperature on record
  • Mean maximum temperatures were above average across Sydney, typically by 0.5 to 1.5°C
  • Mean minimum temperatures were above average at most sites, mostly by less than half a degree
  • Three sites with a relatively short period of observations equalled their highest annual mean temperature on record

Sydney (Observatory Hill)

  • Total rainfall for Sydney (Observatory Hill) was 1000.2 mm; slightly below the long-term annual average of 1215.7 mm
  • Totals of 25 mm or more occurred on 10 days, below the average of 13 days. Four of these days occurred in October and November
  • The wettest day at Observatory Hill was on 28 November, resulting in 105.6 mm, when an intense low pressure system brought severe thunderstorms and heavy rainfall
  • Observatory Hill recorded rainfall in the lowest 10 per cent of records during April, July and August, but in the highest 10 per cent of records during November
  • 2018 was the fifth warmest year on record for maximum temperature and tenth warmest for minimum temperature
  • On 9 April, Observatory Hill recorded its warmest April day on record; the month was also the warmest April on record
  • September recorded the lowest mean daily minimum temperature since 1994 at Observatory Hill
  • The mean daily maximum temperature for Sydney (Observatory Hill) was 23.4 °C, which is 1.7 °C above the long-term average of 21.7 °C. The warmest day was 43.4 °C on 7 January, and the coolest day was on 27 August when the temperature reached 14.5 °C
  • The mean daily minimum temperature for Sydney (Observatory Hill) was 14.9 °C, which is 1.1 °C above the long-term average of 13.8 °C. The coldest morning was 4.6 °C on 16 July, and the warmest morning was on 28 January when the minimum temperature was 24.0 °C

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Extremes in 2018
Hottest day 47.3 °C at Penrith Lakes AWS on 7 Jan
Warmest days on average 26.1 °C at Penrith Lakes AWS
Coolest days on average 18.4 °C at Mount Boyce AWS
Coldest day 3.9 °C at Mount Boyce AWS on 17 Jun
Coldest night -4.9 °C at Camden Airport AWS on 16 Jul
Coolest nights on average 8.4 °C at Mount Boyce AWS
Warmest nights on average 15.8 °C at Sydney Harbour (Wedding Cake West)
Warmest night 24.9 °C at Richmond RAAF on 28 Jan
Warmest on average overall 19.4 °C at Sydney Airport AMO
Coolest on average overall 13.4 °C at Mount Boyce AWS
Wettest overall 1175.4 mm at Norah Head AWS
Driest overall 476.4 mm at Cawdor (Woodburn)
Wettest day 137.4 mm at Castlereagh (Castlereagh Road) on 28 Nov
Strongest wind gust 113 km/h at Wattamolla AWS on 9 Jan

Record lowest annual total rainfall
New record
(mm)
Old
record
Years of
record
Annual
average
Belrose (Evelyn Place) 916.0 919.9 in 1993 25 1268.4
Collaroy (Long Reef Golf Club) 828.2 829.2 in 1970 23 1192.6

Lowest annual total rainfall for at least 20 years
Observed
(mm)
Most recent
lower
Annual
average
Lucas Heights (ANSTO) 575.5 556.3 in 1979* 1005.1
Badgerys Creek AWS 477.0 414.0 in 1997* 671.6

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




Record highest temperature
New record
(°C)
Old
record
Years of
record
Annual
average
Prospect Reservoir 45.3 on 7 Jan 45.1 on 18 Jan 2013 54 23.3
Canterbury Racecourse AWS 44.9 on 7 Jan 44.6 on 18 Jan 2013 24 23.1
Penrith Lakes AWS 47.3 on 7 Jan 46.9 on 11 Feb 2017 24 24.6
Horsley Park Equestrian Centre AWS 45.6 on 7 Jan 44.9 on 18 Jan 2013 22 23.8



Record highest annual mean daily maximum temperature
New record
(°C)
Old
record
Years of
record
Annual
average
Bankstown Airport AWS 24.9 = 24.9 in 2016 48 23.3
Parramatta North (Masons Drive) 24.5 = 24.5 in 2017 48 23.4
Camden Airport AWS 25.1 = 25.1 in 1980 39 23.7
Mount Boyce AWS 18.4 18.3 in 2017 26 17.0
Richmond RAAF 25.9 25.6 in 2017 24 24.2
Penrith Lakes AWS 26.1 25.7 in 2017 22 24.6
Horsley Park Equestrian Centre AWS 24.8 24.7 in 2017 20 23.8



Record lowest temperature
New record
(°C)
Old
record
Years of
record
Annual
average
Mangrove Mountain AWS -0.8 on 30 Aug -0.5 on 26 Jun 2016 25 11.7
Canterbury Racecourse AWS -1.6 on 16 Jul = -1.6 on 3 Jul 2002 24 12.4
Penrith Lakes AWS -1.8 on 16 Jul -1.4 on 12 Jul 2002 24 12.4



Record highest annual mean temperature
New record
(°C)
Old
record
Years of
record
Annual
average
Mount Boyce AWS 13.4 = 13.4 in 2017 26 12.5
Richmond RAAF 18.6 = 18.6 in 2017 23 17.7
Penrith Lakes AWS 19.3 = 19.3 in 2017 22 18.5



Summary statistics for 2018
Maximum temperatures
(°C)
Minimum temperatures
(°C)
Rainfall
(millimetres)
Mean
for
2018
Diff
from
average
Highest
for
2018
Mean
for
2018
Diff
from
average
Lowest
for
2018
Total
for
2018
Average
annual
total
Rank
of
2018
Fraction
of annual
average
Bankstown Airport AWS 24.9 +1.6 45.2 7 Jan 12.3 +0.3 -1.4 16 Jul 679.0 868.0 low 78%
Camden Airport AWS 25.1 +1.4 45.7 7 Jan 10.5 +0.3 -4.9 16 Jul 562.4 782.1 low 72%
Campbelltown (Mount Annan) 25.0 +1.0 45.1 7 Jan 10.8 +0.1 -3.7 16 Jul 529.6 721.1 low 73%
Canterbury Racecourse AWS 23.6 +0.5 44.9 7 Jan 12.4 0.0 -1.6 16 Jul
Cooranbong (Lake Macquarie AWS) 24.2   43.4 7 Jan 11.3   -3.4 16 Jul 859.8
Gosford AWS 23.3   43.7 7 Jan 13.1   0.9 22 Jul
Holsworthy (Defence) 24.1   45.9 7 Jan 11.4   -0.4 23 Jul 932.6
Holsworthy Aerodrome AWS 24.1   45.2 7 Jan 11.9   -1.8 16 Jul 556.6
Horsley Park Equestrian Centre AWS 24.8 +1.0 45.6 7 Jan 12.1 0.0 -1.7 16 Jul 603.8 757.3 low 80%
Mangrove Mountain AWS 23.2 +1.4 44.0 7 Jan 11.5 -0.2 -0.8 30 Aug 981.0 1103.8 average 89%
Mount Boyce AWS 18.4 +1.4 37.0 7 Jan 8.4 +0.4 -2.6 15 Jul 930.0 971.1 average 96%
Norah Head AWS 23.2 +0.9 37.1 18 Mar 15.4 +0.2 5.1 15 Jul 1175.4 1153.5 average 102%
Parramatta North (Masons Drive) 24.5 +1.1 45.0 7 Jan 12.3 +0.1 0.0 16 Jul 722.3 967.1 low 75%
Penrith Lakes AWS 26.1 +1.5 47.3 7 Jan 12.4 0.0 -1.8 16 Jul 684.0 717.0 average 95%
Richmond RAAF 25.9 +1.7 46.3 7 Jan 11.3 +0.2 -4.3 15 Jul 524.2 728.4 v low 72%
Springwood (Valley Heights) 23.3 +0.9 43.2 7 Jan 12.2 +0.2 1.6 15 Jul 764.2 1082.1 low 71%
Sydney (Observatory Hill) 23.4 +1.7 43.4 7 Jan 14.9 +1.1 4.6 16 Jul
Sydney Airport AMO 23.9 +1.6 43.7 7 Jan 14.8 +1.3 4.2 16 Jul 826.4 1080.8 low 76%
Sydney Harbour (Wedding Cake West) 21.3 0.0 38.2 18 Mar 15.8 +0.1 6.1 16 Jul
Sydney Olympic Park AWS (Archery Centre) 24.2   44.5 7 Jan 12.9   -0.9 16 Jul 855.0
Terrey Hills AWS 22.2 +0.3 42.7 7 Jan 13.3 0.0 1.3 16 Jul

Notes

The Annual climate summary, generally published on the second working day of the year, 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.

This summary includes 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 7 am on Friday 4 January 2019. 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
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