Greater Sydney in summer 2018-19: very warm, average rainfall

Summer 2018-19 rainfall across Greater Sydney was close to average in nearly all suburbs. Temperatures were warmer than normal following several heatwave events during December and January.

Rainfall close to average

  • Summer 2018-19 rainfall totals were close to average across Greater Sydney, wetter than the previous summer 2017-18
  • December saw above average rainfall followed by near-average January totals and most sites in February experienced below average totals
  • The wettest day of summer was on 14 December where 80.6 mm was recorded at Holsworthy (Defence) as a result of widespread thunderstorms
  • Rain was recorded at Sydney (Observatory Hill) on 34 days; close to the summer average of 36 rain days

Warm days and nights

  • Daytime temperatures in summer across Greater Sydney were generally one to three degrees warmer than normal
  • The warmest days of summer was 42.4 °C recorded at Penrith Lakes Aws on both 5 and 17 January, the coolest summer day was 14.3 ºC recorded at Katoomba (Murri St) on 5 December
  • A record run of consecutive hot days of 35 °C or higher was experienced at Penrith Lakes, recording 9 days from 25 December to 2 January (previous was 7 consecutive days between 30 January to 5 February 2011)
  • January was the warmest month on record, with many sites setting records for their hottest overall January mean maximum and mean minimum temperatures
  • Overnight temperatures were around one to two degrees warmer than average for sites across Greater Sydney
  • Several records were set for consecutive number of warm nights of 20 ºC or more during January, including Sydney (Observatory Hill) between 8 to 31 January (previous was 12 consecutive days 17 to 28 January 2013)
  • Clear conditions generated by a high pressure system in the Tasman Sea, led to the coolest overnight temperatures for summer on 24 December, overnight temperatures at most locations did not exceed 15 ºC

Sydney (Observatory Hill)

  • Total rainfall for Sydney (Observatory Hill) was 229.2 mm, which is 77% of the long-term average of 296.3 mm
  • The mean daily maximum temperature for Sydney (Observatory Hill) was 28.0 °C, which is 2.3 °C above the long-term average of 25.7 °C. The warmest day was 39.6 °C on 31 Jan, and the coolest day was on 23 Feb when the temperature reached 21.1 °C
  • The mean daily minimum temperature for Sydney (Observatory Hill) was 20.2 °C, which is 1.8 °C above the long-term average of 18.4 °C. The coldest morning was 14.9 °C on 24 Dec, and the warmest morning was on 19 Jan when the minimum temperature was 23.5 °C

Dust and thunderstorms

  • A severe thunderstorm impacted Sydney on 20 December and brought intense rain, damaging winds and giant hail resulting in extensive property damage
  • On the evening of 8 February, a severe thunderstorm impacted parts of the Sydney CBD generating heavy falls and flash flooding in some areas
  • Raised dust over Sydney on 12 February reduced air quality levels for a few days before moving offshore

Further information

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Extremes in summer 2018-19
Hottest day 42.4 °C at Penrith Lakes AWS on 5 & 17 Jan 2019
Warmest days on average 31.6 °C at Richmond RAAF
Coolest days on average 24.8 °C at Sydney Harbour (Wedding Cake West)
Coldest day 14.3 °C at Katoomba (Murri St) on 5 Dec 2018
Coldest night 7.5 °C at Mount Boyce AWS on 3 & 24 Dec 2018
Coolest nights on average 14.6 °C at Mount Boyce AWS
Warmest nights on average 20.3 °C at Sydney Harbour (Wedding Cake West)
Warmest night 24.0 °C at Sydney Olympic Park AWS (Archery Centre) on 19 Jan 2019 & at Richmond RAAF on 5 Feb 2019
Warmest on average overall 25.1 °C at Richmond RAAF
Coolest on average overall 20.2 °C at Mount Boyce AWS
Wettest overall 351.0 mm at Blackheath (Wombat Street)
Driest overall 152.0 mm at Milperra Bridge (Georges River)
Wettest day 80.6 mm at Holsworthy (Defence) on 14 Dec 2018
Strongest wind gust 107 km/h at Wattamolla AWS on 31 Jan 2019

Summary statistics for summer 2018-19
Maximum temperatures
(°C)
Minimum temperatures
(°C)
Rainfall
(millimetres)
Mean for
summer
2018-19
Diff
from
average
Highest for
summer
2018-19
Mean for
summer
2018-19
Diff
from
average
Lowest for
summer
2018-19
Total for
summer
2018-19
Average
for
summer
Rank of
summer
2018-19
Fraction of
summer
average
Bankstown Airport AWS 30.5 +2.6 40.0 31 Jan 2019 19.0 +1.3 12.6 24 Dec 2018 258.8 261.4 average 99%
Camden Airport AWS 31.2 +2.2 40.9 26 Jan 2019 17.6 +1.3 10.5 24 Dec 2018 218.2 237.8 average 92%
Campbelltown (Mount Annan) 30.9 +1.9 40.1 5 Jan 2019 17.4 +1.0 10.7 24 Dec 2018 230.0 236.6 average 97%
Canterbury Racecourse AWS 28.6 +1.4 38.9 31 Jan 2019 18.9 +1.0 11.8 24 Dec 2018 239.0 243.4 average 98%
Cooranbong (Lake Macquarie AWS) 29.3 +1.2 40.3 26 Jan 2019 17.6 +0.6 10.8 7 Dec 2018 219.2 313.0 low 70%
Gosford AWS 28.5   40.8 5 Jan 2019 18.8   12.3 24 Dec 2018
Holsworthy (Defence) 30.3   40.9 28 Dec 2018 17.7   10.4 24 Dec 2018 297.4
Holsworthy Aerodrome AWS 30.0   40.2 31 Jan 2019 18.6   10.7 24 Dec 2018 235.6
Horsley Park Equestrian Centre AWS 30.7 +1.7 39.6 18 Jan 2019 18.2 +0.9 11.4 24 Dec 2018 234.6 245.5 average 96%
Mangrove Mountain AWS 29.4 +2.6 39.7 26 Jan 2019 17.2 +0.8 10.8 24 Dec 2018 322.6 332.3 average 97%
Mount Boyce AWS 25.9 +2.7 36.1 17 Jan 2019 14.6 +1.9 7.5 3 Dec 2018 343.2 325.2 average 106%
Norah Head AWS 27.1 +1.4 39.5 5 Jan 2019 19.8 +0.4 15.2 24 Dec 2018
Parramatta North (Masons Drive) 30.2 +2.2 39.2 31 Jan 2019 18.1 +0.9 10.2 24 Dec 2018 230.0 300.6 average 77%
Richmond RAAF 31.6 +2.1 41.4 17 Jan 2019 18.5 +1.3 11.9 24 Dec 2018 246.2 274.8 average 90%
Springwood (Valley Heights) 29.4 +1.9 39.6 5 Jan 2019 17.5 +1.0 11.6 24 Dec 2018 290.4 364.8 average 80%
Sydney (Observatory Hill) 28.0 +2.3 39.6 31 Jan 2019 20.2 +1.8 14.9 24 Dec 2018 229.2 296.3 average 77%
Sydney Airport AMO 29.0 +2.7 40.6 31 Jan 2019 20.1 +1.6 15.0 24 Dec 2018 216.4 279.1 average 78%
Sydney Harbour (Wedding Cake West) 24.8 +0.4 36.2 31 Jan 2019 20.3 +0.4 15.7 23 Dec 2018
Sydney Olympic Park AWS (Archery Centre) 29.6   40.2 31 Jan 2019 19.3   12.4 24 Dec 2018
Terrey Hills AWS 27.2 +1.1 37.3 31 Jan 2019 18.4 +0.7 12.7 24 Dec 2018 282.2 302.6 average 93%

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.

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 10 am on Friday 1 March 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
Enquiries