Greater Melbourne in winter 2018: drier than average, mild days

Winter rainfall was near-average to below average across Greater Melbourne. Daytime temperatures were generally slightly warmer than average, while night time temperatures were close to or slightly cooler than average.

Below average rainfall

  • Winter rainfall across Greater Melbourne was below average at most reporting sites, owing mostly to drier conditions throughout July and August; June rainfall was mostly close to average
  • Rainfall totals ranged from 65% of average at Laverton RAAF to 104% of average at Coldstream
  • The highest daily rainfall total during winter was 60.0 mm at Warburton on 8 August, which was also Greater Melbourne's overall wettest place with 386.0 mm for the season
  • On 18 June, Wallan (Kilmore Gap) had its highest winter daily rainfall on record

Mild daytime temperatures

  • Minimum temperatures during winter were close to average at most reporting sites in Greater Melbourne
  • Winter in Greater Melbourne began with cold mornings as minimum temperatures dropped below 5 °C at most sites in the first few days of June
  • The coldest mornings during winter were under high pressure systems with clear skies, light winds, and cold, dry air; the coldest temperatures recorded in Greater Melbourne were −4.2 °C on 29 August and −3.5 °C on 2 July, both at Coldstream
  • Wallan (Kilmore Gap) and Cranbourne Botanic Gardens had their lowest winter mean daily minimum temperature since 1997
  • Daytime temperatures tended to be warmer than average across most suburbs in Greater Melbourne, with some sites reporting temperatures about a half degree above their winter average
  • The warmest daytime temperature during winter in Greater Melbourne, 20.0 °C, was recorded on 10 August at Melbourne (Olympic Park), in a warm northerly airflow

Melbourne (Olympic Park)

  • Total rainfall for Melbourne (Olympic Park) was 105.4 mm
  • The mean daily maximum temperature for Melbourne (Olympic Park) was 14.7 °C. The warmest day was 20.0 °C on 10 Aug, and the coolest day was on 28 Jun when the temperature reached 10.6 °C
  • The mean daily minimum temperature for Melbourne (Olympic Park) was 7.3 °C. The coldest morning was 0.8 °C on 29 Aug, and the warmest morning was on 5 Jul when the minimum temperature was 12.7 °C

Strong winds and thunderstorms

  • The strongest wind gust recorded during winter in Greater Melbourne was 126 km/h at South Channel Island on the 17th July, when a cold front with thunderstorms swept across the city; strong winds downed trees, damaged properties, and caused power outages and train delays
  • During a cold outbreak on 18th and 19th August, Greater Melbourne experienced showers, thunderstorms and hail; snow settled on the ground in the Dandenong Ranges

Further information

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Extremes in winter 2018
Hottest day 20.0 °C at Melbourne (Olympic Park) on 10 Aug
Warmest days on average 14.7 °C at Laverton RAAF
14.7 °C at Melbourne (Olympic Park)
Coolest days on average 10.1 °C at Wallan (Kilmore Gap)
Coldest day 6.5 °C at Wallan (Kilmore Gap) on 11 Jul
Coldest night -4.2 °C at Coldstream on 29 Aug
Coolest nights on average 3.7 °C at Coldstream
Warmest nights on average 7.3 °C at Melbourne (Olympic Park)
Warmest night 13.3 °C at Laverton RAAF on 8 Jun
13.3 °C at Bundoora (Latrobe University) on 5 Jul
Warmest on average overall 11.0 °C at Melbourne (Olympic Park)
Coolest on average overall 7.0 °C at Wallan (Kilmore Gap)
Wettest overall 386.0 mm at Warburton (O'Shannassy Reservoir (Quarte
Driest overall 78.4 mm at Laverton RAAF
Wettest day 60.0 mm at Warburton (O'Shannassy Reservoir (Quarte on 8 Aug
Strongest wind gust 126 km/h at South Channel Island on 17 Jul

Record highest winter daily rainfall
New record
(mm)
Old
record
Years of
record
Wallan (Kilmore Gap) 47.0 on 18 Jun 36.4 on 11 Jun 2005 25



Lowest winter mean daily minimum temperature for at least 20 years
Observed
(°C)
Most recent
lower
Average for
winter
Cranbourne Botanic Gardens 5.6 4.9 in 1997 6.4
Wallan (Kilmore Gap) 4.0 3.7 in 1997 4.4



Summary statistics for winter 2018
Maximum temperatures
(°C)
Minimum temperatures
(°C)
Rainfall
(millimetres)
Mean for
winter
2018
Diff
from
average
Highest for
winter
2018
Mean for
winter
2018
Diff
from
average
Lowest for
winter
2018
Total for
winter
2018
Average
for
winter
Rank of
winter
2018
Fraction of
winter
average
Coldstream 14.1 +0.1 19.1 6 Jun 3.7 -0.4 -4.2 29 Aug 203.6 196.4 average 104%
Cranbourne Botanic Gardens 14.3 +0.4 19.4 3 Aug 5.6 -0.8 -0.8 29 Aug 223.4 229.3 average 97%
Essendon Airport 14.5 +0.8 19.4 10 Aug 6.0 +0.3 -2.4 29 Aug 88.2 131.1 low 67%
Ferny Creek 10.3   15.0 5 Jul 5.0   1.2 12 Aug 275.8
Laverton RAAF 14.7 +0.4 19.9 10 Aug 5.7 +0.2 -2.1 29 Aug 78.4 121.1 low 65%
Melbourne (Olympic Park) 14.7   20.0 10 Aug 7.3   0.8 29 Aug 105.4
Melbourne Airport 14.3 +0.5 19.2 10 Aug 5.4 -0.5 -2.0 29 Aug 106.8 119.5 average 89%
Moorabbin Airport 14.6 +0.3 19.5 10 Aug 6.5 -0.1 -1.6 29 Aug 122.8 182.5 low 67%
Scoresby Research Institute 14.4 +0.8 19.4 28 Jul 5.8 -0.3 -2.3 29 Aug 153.6 222.7 low 69%
Viewbank 14.5 0.0 19.3 5 Jul 5.6 -0.6 -2.7 29 Aug 131.2 157.1 low 84%
Wallan (Kilmore Gap) 10.1 +0.3 15.1 10 Aug 4.0 -0.4 0.4 29 Aug 184.2 190.6 average 97%

Notes

The Seasonal climate summary, generally published on the first working day of each month, lists the main features of the weather in Greater Melbourne 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 Melbourne “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 9 am on Monday 3 September 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