Greater Melbourne in December 2018: wet with very warm nights

Rainfall in December 2018 was above average across Greater Melbourne. Night time temperatures were much warmer than average.

Above average rainfall

  • December rainfall was above average at all sites in the Melbourne metropolitan area, except in Scoresby where it was average
  • The wettest period was mid-month, when a slow-moving low pressure trough, which brought moisture from the tropics, and a low pressure system with the associated cold front, brought widespread rainfall, with daily totals exceeding 30 mm at some sites
  • The highest daily rainfall total was 65.0 mm at Main Ridge on the 13th
  • The wettest place in Greater Melbourne in December was Melbourne Airport, which received 114.4 mm during the month
  • Cerberus and Laverton RAAF had their highest total December rainfall since 1993

Very warm nights

  • Night time temperatures at all sites in Greater Melbourne were much warmer than average, with most sites reporting temperatures between 2 °C and 3 °C warmer than the December average
  • The warmest night time temperature was 26.3 °C at Laverton RAAF on the 7th, in a warm northerly airflow
  • Many sites had their highest December mean daily minimum temperature on record
  • Daytime temperatures were also warmer than average at all reporting sites
  • Melbourne's two warmest periods for the month were on the 6th to 7th and 27th to 28th, when warm northerly winds resulted in maximum temperatures in the high-30s at most sites
  • In Greater Melbourne, the warmest daytime temperatures for the month, 40.8 °C, was recorded at Viewbank on the 27th

Melbourne (Olympic Park)

  • Total rainfall for Melbourne (Olympic Park) was 104.8 mm
  • The mean daily maximum temperature for Melbourne (Olympic Park) was 25.7 °C. The warmest day was 38.0 °C on the 7th, and the coolest day was on the 22nd when the temperature reached 19.1 °C
  • The mean daily minimum temperature for Melbourne (Olympic Park) was 16.0 °C. The coldest morning was 10.3 °C on the 1st, and the warmest morning was on the 7th when the minimum temperature was 25.1 °C

Storms and flesh floods

  • Strong winds, heavy rain, and severe thunderstorms affected Greater Melbourne on the 13th and 14th
  • On the 14th, 41.2 mm fell in Melbourne, most of it in a 20-minute period after 5 pm. The State Emergency Service was called to rescue 25 people whose vehicles became trapped in flood waters
  • Train lines in the eastern suburbs were seriously disrupted by flash flooding, while the inner east and southeast were most affected by building damage

Further information

Media
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Enquiries

Extremes in December 2018
Hottest day 40.8 °C at Viewbank on the 27th
Warmest days on average 26.9 °C at Coldstream
Coolest days on average 23.0 °C at Ferny Creek
Coldest day 15.4 °C at Wallan (Kilmore Gap) on the 13th
Coldest night 5.0 °C at Coldstream on the 1st
Coolest nights on average 12.7 °C at Wallan (Kilmore Gap)
Warmest nights on average 16.0 °C at Melbourne (Olympic Park)
Warmest night 26.3 °C at Laverton RAAF on the 7th
Warmest on average overall 20.9 °C at Melbourne (Olympic Park)
Coolest on average overall 18.0 °C at Ferny Creek
Wettest overall 114.4 mm at Melbourne Airport
Wettest day 65.0 mm at Main Ridge on the 13th
Strongest wind gust 91 km/h at St Kilda Harbour - RMYS on the 2nd

Highest December total rainfall for at least 20 years
Observed
(mm)
Most recent
higher
Average for
December
Cerberus 98.4 103.6 in 1988* 55.1
Laverton RAAF 100.6 101.2 in 1993 46.8

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




Record highest December mean daily minimum temperature
New record
(°C)
Old
record
Years of
record
Average for
December
Laverton RAAF 15.0 14.1 in 2017 75 12.0
Scoresby Research Institute 14.3 13.8 in 2003 59 11.9
Essendon Airport 14.9 14.2 in 1965 48 11.9
Melbourne Airport 14.3 13.8 in 1994 48 12.1
Moorabbin Airport 15.4 14.6 in 2017 47 12.7
Cranbourne Botanic Gardens 13.7 13.5 in 1992 26 11.8
Wallan (Kilmore Gap) 12.7 12.5 in 2015 25 10.3
Coldstream 13.0 12.0 in 2017 24 9.8

Highest December mean daily minimum temperature for at least 20 years
Observed
(°C)
Most recent
higher
Average for
December
Cerberus 13.9 14.0 in 1992 11.9



Record highest December mean temperature
New record
(°C)
Old
record
Years of
record
Average for
December
Cerberus 19.3 = 19.3 in 2015 27 17.2
Coldstream 20.0 19.9 in 2015 24 17.5



Summary statistics for December 2018
Maximum temperatures
(°C)
Minimum temperatures
(°C)
Rainfall
(millimetres)
Mean for
December
2018
Diff
from
average
Highest for
December
2018
Mean for
December
2018
Diff
from
average
Lowest for
December
2018
Total for
December
2018
Average
for
December
Rank of
December
2018
Fraction of
December
average
Cerberus 24.6 +2.2 37.5 7th 13.9 +2.0 7.6 1st 98.4 55.1 v high 179%
Coldstream 26.9 +1.6 39.3 27th 13.0 +3.2 5.0 1st 101.0 61.6 high 164%
Cranbourne Botanic Gardens 25.5 +1.9 36.5 28th 13.7 +1.9 8.2 1st 93.8 68.8 high 136%
Essendon Airport 26.2 +1.6 40.3 27th 14.9 +3.0 9.0 1st 69.8 52.6 high 133%
Ferny Creek 23.0   34.7 27th 12.9   7.1 3rd 87.4
Laverton RAAF 25.6 +1.7 39.2 7th 15.0 +3.0 8.2 1st 100.6 46.8 v high 215%
Melbourne (Olympic Park) 25.7   38.0 7th 16.0   10.3 1st 104.8
Melbourne Airport 26.1 +1.5 39.8 27th 14.3 +2.2 8.2 1st 114.4 51.8 v high 221%
Moorabbin Airport 26.0 +2.0 38.5 7th 15.4 +2.7 9.5 1st 98.2 61.0 high 161%
Scoresby Research Institute 26.4 +2.3 39.8 27th 14.3 +2.4 7.1 1st 69.4 76.4 average 91%
Viewbank 26.9 +1.1 40.8 27th 14.7 +2.0 7.7 1st 104.4 72.3 high 144%
Wallan (Kilmore Gap) 24.6 +2.3 37.8 27th 12.7 +2.4 7.3 3rd 83.4 48.6 high 172%

Daily maximum temperatures for December 2018
12345678910111213141516171819202122232425262728293031
Bundoora (Latrobe University)24.321.527.836.022.426.333.820.024.3
Cerberus31.418.019.718.521.834.937.527.920.019.523.933.819.523.026.623.621.820.526.320.623.519.021.833.222.122.333.335.022.420.821.4
Coldstream29.819.123.320.927.533.536.028.920.723.728.332.119.423.825.522.623.424.826.923.822.919.527.232.232.631.639.336.624.123.630.5
Cranbourne Botanic Gardens30.618.520.718.524.334.536.228.722.026.333.119.223.524.622.422.822.222.518.424.033.023.934.536.522.921.224.0
Essendon Airport31.520.623.520.625.135.337.830.620.521.425.134.120.423.324.223.922.122.028.120.922.219.627.133.626.026.540.336.522.821.325.6
Ferny Creek26.415.818.015.622.630.431.726.518.219.923.228.016.720.121.419.420.119.825.020.318.615.823.129.027.427.934.732.321.118.525.2
Laverton RAAF32.520.123.419.626.436.539.227.721.221.025.535.119.123.524.722.222.121.026.621.122.118.924.533.923.823.733.936.522.421.023.2
Melbourne (Olympic Park)31.719.523.620.525.235.538.030.320.120.623.633.621.122.724.823.521.820.826.921.220.919.126.934.223.923.837.436.423.922.723.5
Melbourne Airport31.219.823.620.425.135.138.430.420.721.725.533.819.723.723.923.023.022.626.120.922.119.026.933.326.128.139.835.822.420.625.4
Moorabbin Airport32.019.222.720.026.135.838.528.621.621.427.034.321.022.425.423.420.721.025.421.623.419.225.433.625.226.137.136.323.822.024.4
Scoresby Research Institute30.619.122.320.626.534.436.329.322.427.432.220.323.625.323.322.723.428.022.423.520.126.833.729.328.639.824.122.327.9
Viewbank31.319.123.922.027.735.037.529.721.423.227.834.020.323.324.223.123.223.928.022.322.620.427.933.929.028.140.836.423.422.527.5
Wallan (Kilmore Gap)27.617.521.719.025.831.635.028.616.620.626.030.215.420.321.618.721.722.623.419.920.417.125.430.232.229.337.837.122.719.028.4
Values are the maximum temperature, usually in the 24 hours from 9 am on the day indicated,
and typically occurred in the afternoon of that day.
Temperatures coloured according to their difference
from the long-term average for the period
-10.0 -9.0 -8.0 -7.0 -6.0 -5.0 -4.0 -3.0 -2.0 -1.0 0.0 +1.0 +2.0 +3.0 +4.0 +5.0 +6.0 +7.0 +8.0 +9.0 +10.0 °C Grey outline marks highest
and lowest for the period

Daily minimum temperatures for December 2018
12345678910111213141516171819202122232425262728293031
Bundoora (Latrobe University)13.011.812.325.811.713.716.414.413.7
Cerberus7.612.012.012.410.310.018.120.114.712.59.016.218.515.717.114.012.315.216.014.214.913.78.910.912.411.211.519.318.616.415.9
Coldstream5.011.26.212.35.79.819.820.215.615.39.512.117.313.615.613.712.315.314.214.212.66.68.810.19.511.719.620.117.515.5
Cranbourne Botanic Gardens8.211.011.811.29.610.919.320.314.510.113.318.214.316.013.213.815.014.111.58.711.59.513.220.818.516.215.9
Essendon Airport9.011.911.112.312.712.325.021.915.314.812.614.115.914.915.315.413.915.516.415.413.313.210.712.514.012.514.521.319.817.416.7
Ferny Creek8.68.87.19.38.513.121.620.112.311.79.614.215.913.113.613.112.411.312.514.310.99.38.513.314.99.916.621.717.315.411.9
Laverton RAAF8.212.110.912.414.811.526.323.115.614.213.813.516.415.616.516.314.115.615.113.913.410.511.913.511.513.821.019.517.917.1
Melbourne (Olympic Park)10.312.213.313.413.414.525.122.716.015.813.016.016.916.417.215.815.616.716.816.915.414.111.514.315.813.316.221.921.018.217.3
Melbourne Airport8.212.011.011.811.712.524.321.514.914.411.313.015.614.214.715.513.515.016.114.712.611.89.711.512.411.514.320.719.216.715.8
Moorabbin Airport9.512.813.313.111.111.624.621.515.715.811.617.116.017.415.016.016.717.515.613.110.413.212.214.822.020.217.416.7
Scoresby Research Institute7.111.811.012.69.811.724.221.315.015.311.414.917.114.715.514.213.315.416.415.613.710.912.912.110.912.920.717.016.0
Viewbank7.711.612.413.111.412.922.921.315.515.511.714.516.015.215.614.513.415.515.915.012.78.312.513.812.814.120.920.017.416.5
Wallan (Kilmore Gap)8.58.97.39.39.011.920.621.413.011.59.812.513.311.112.312.312.711.714.110.09.67.713.317.210.715.321.317.215.012.3
Values are the minimum temperature, usually in the 24 hours to 9 am on the day indicated,
and typically occurred that morning.
Temperatures coloured according to their difference
from the long-term average for the period
-10.0 -9.0 -8.0 -7.0 -6.0 -5.0 -4.0 -3.0 -2.0 -1.0 0.0 +1.0 +2.0 +3.0 +4.0 +5.0 +6.0 +7.0 +8.0 +9.0 +10.0 °C Grey outline marks highest
and lowest for the period

Daily rainfall for December 2018
12345678910111213141516171819202122232425262728293031
Berwick (Buchanan Road) - 19.6 1.4 3.0 - - - 0.2 3.2 - - - 4.2 13.6 2.4 2.6 11.2 - - 0.2 - 12.4 - - - - - - 0.6 3.0 0.6
Bonbeach (Carrum) - 17.0 1.0 2.0 - - - - - - - - - 45.0 3.2 14.3 - - - - - 16.0 - - - - - - 1.6 2.4
Bullengarook East - 7.6 0.2 0.4 - - - - 1.6 3.8 - - 2.0 20.8 38.6 1.6 0.4 0.2 - 0.2 6.8 8.4 - - - - - - 1.6 1.4 1.2
Bundoora (Latrobe University) 10.4 - - - - 3.2 - - 22.2 17.0 21.4













Burnside - 4.0 - - - - - - - - - - 19.8 12.0 20.0 0.8 14.8 - - - 1.6 17.0 - - - - - - 1.2 1.0 -
Cape Schanck - 14.8 - 1.8 - - - 0.6 - - - - 24.4 38.2 6.8 4.6 - 0.6 - - 2.8 - - - - - - - 3.0

Cerberus - 10.6 0.6 - - - - - - - - - 19.6 10.8 7.4 17.2 - - - - 1.0 26.8 - - - - - - 1.2 3.0 0.2
Cheltenham Kingston Centre - 13.2 - 0.8 - - - - - - - - 11.0 14.0 7.2 4.0 2.4 - - - 0.2 - - 4.8 - - - - - 1.8 1.0
Coldstream - 19.2 - 1.6 - - - - 0.8 2.8 - - 20.4 18.8 17.0 6.8 2.8 - - - - 7.4 - - - - - - - 1.8 1.6
Cranbourne Botanic Gardens - 17.0 1.6 1.8 - - - - - - - - 9.8 16.8 0.4 23.0 6.2 - 0.2 11.9 0.1 - - - - - 1.0 3.0 1.0
Dromana Sussex Farm - 13.4 1.2 1.0 0.4 - - - - - - - 21.2 27.4 6.2 3.2 - - - - 2.6 8.4 - - - - - - 1.8 1.0 0.4
Essendon Airport - 10.4 - - - - - 0.2 2.0 0.2 - - 13.4 12.6 10.2 1.8 2.8 - - - 2.0 11.2 - - - - - - 1.0 1.2 0.8
Ferny Creek - 20.0 0.4 5.4 0.2 - - 0.2 1.2 - - - 7.6 19.4 6.4 2.0 0.6 0.4 - - 6.0 11.2 - - - - - - 0.4 2.6 3.4
Gladysdale (Little Feet Farm) - 25.2 1.4 2.6 - - - 2.2 0.4 - - 10.0 13.0 5.2 - - - 4.6 7.2 - - - - - 4.6
Greenvale Reservoir - 2.4



-
0.8 1.0

6.4


0.8 - - - 3.0 12.0 0.2



-
-
Kinglake West - 19.8 0.2 1.8 - - - 0.2 2.2 4.0 - - 14.8 24.2 21.8 1.6 - - 0.4 4.8 2.6 - - - - - - - 1.6
Kinglake West (Wallaby Creek) - 18.8

0.2
-
1.6 8.0

1.8

10.6 2.2 - - 0.4 3.2 2.0 -



- - 0.4
Lancefield - 5.4 - - - - 1.4 10.2 - - 6.8 24.0 26.8 2.8 0.8 - - 0.6 0.6 5.2 - - - - - - 0.4 1.4
Laverton RAAF - 6.0 - - - - - - - - - - 20.6 17.8 24.8 1.0 5.6 0.2 - - 2.8 19.6 - - - - - - 1.2 0.6 0.4
Main Ridge - 9.4 - 3.6 - - - - - - - - 65.0 9.8 - 3.4 - - - - 4.0 - - - - 2.0 - - 1.4 2.0
Melbourne (Olympic Park) - 10.4 - - - - - - 1.2 - - - 16.2 16.6 41.2 3.8 2.0 - - - 1.0 9.8 - - - - - - 1.2 0.6 0.8
Melbourne Airport - 7.6 0.2 - - - - - 1.2 0.2 0.2 - 20.8 18.4 22.2 2.2 0.6 - - - 2.0 34.0 - - - - - - 1.0 0.8 3.0
Mitcham - 15.4



- 0.4 0.8 -

1.6

5.2 1.4 - - - - 6.2 -



- 0.4 2.0
Montrose - 13.2 - 4.0 - - - 0.4 1.8 - - - 6.2 17.4 9.8 8.8 1.2 - - - - 9.4 - - - - - - 0.4 1.4 0.4
Moorabbin Airport - 14.2 - 0.6 - - - - - - - - 15.8 21.2 6.2 1.4 13.8 0.2 - - - 20.2 - - - - - - 0.8 1.4 2.4
Mount Waverley (Riversdale Golf Club) 11.8 - 2.2 0.8 0.2 - - - 1.8 - - - - 23.1 21.3 2.8 5.5













Newham (Cobaw) - 8.0 - - - - - - 1.0 15.4 - - 5.6 10.4 24.0 2.8 1.4 - - - - 3.4 - - - - - - 1.0 1.0
Oakleigh (Metropolitan Golf Club) - 21.0 - - - - - 5.2 - - 9.4 26.6 8.6 - 9.8 - - - - 9.8 - - - - - - 5.0
Preston Reservoir - 9.6 0.2


- 0.6 0.6 0.2

7.2

3.8 3.4 - - - - 4.0 -



- 0.6 1.6
Romsey - 7.8 - 0.2 - - - 0.6 - 7.4 - - 8.2 24.4 24.2 1.8 0.8 - 0.2 - 1.4 13.6 - - - - - - 1.4 1.8 0.2
Rosebud (Country Club) - 9.2 1.8 - - - - - - - - 22.6 27.8 6.2 3.2 - - - 2.2 1.6








Scoresby Research Institute - 13.4 0.2 2.0 - - - - 1.0 - - - 1.2 21.4 16.4 3.0 1.8 - - - 0.2 5.0 0.2 - - - - - 0.4 1.4 1.8
Springvale (Sandown) - 16.4 - 1.8 - - - - - - - - 38.6 22.0 7.4 3.6 - - - - - 5.5 - - - - - - - - 4.0
Springvale Necropolis 17.0 - - - - - - - - - 2.0 40.0 30.0 - - - - 9.0 - - - - 3.0
Toorourrong Reservoir (Toorourrong) - 17.6 0.2


-
1.4 4.2

1.8

9.8 0.2 0.2 - - 1.8 1.0 -



- - 0.2
Upper Plenty - 12.8 - 0.6 - - - 0.6 2.0 3.8 - - 17.6 28.0 24.6 8.8 - - - 0.4 4.4 0.6 - - - - - - 0.2 1.2
Viewbank - 11.8 0.2 - - - - - 0.4 0.4 - - 17.8 19.2 38.0 5.0 2.2 - - - - 6.4 - - - - - - 0.6 1.4 1.0
Wallan - 12.6 - - - - - 1.0 - 3.6 - - 11.0 26.2 25.2 3.4 0.4 - - 0.6 2.0 2.0 - - - - - - - 2.4
Wallan (Kilmore Gap) - 13.0 0.2 0.2 0.2 - - - 1.8 4.8 - - 18.6 16.6 18.8 3.4 - 0.2 - 0.2 1.6 2.2 - - - - - - 0.2 1.4 -
Warburton (O'Shannassy Reservoir (Quarte -



1.8 -
2.6 -

3.8

1.4 1.8 - - - - 5.4 -



- - 0.8
Willowmavin (Avalon Station) - 6.4 0.2 - - - - 0.2 1.0 10.8 - - 4.4 30.6 19.4 1.2 2.0 0.2 - 0.2 0.8 7.4 0.2 - - - - 0.2 - 1.2 -
Woodend - 6.4 - 0.2 - - - - 1.0 7.6 - - 3.4 19.0 36.0 2.2 2.6 0.2 - 0.4 1.8 6.0 - - - - - - 1.0 1.8 1.4
Yan Yean - 1.2



-
1.0 1.0

1.0


3.2 - - - 1.0 0.4 -



- - 0.4
Yarra River @ Warrandyte - 12.8 0.2 0.2 - - - - 5.6 1.4 - - 5.8 15.0 44.8 7.0 1.4 - - 0.2 0.2 5.2





0.2 1.2 1.6
Most values are the precipitation in the 24 hours to 9 am on the day indicated. Days marked with → are part of a longer accumulation, which is shown on the final day.
Values over 100 mm have been rounded to the nearest whole millimetre.
Days marked with - have a rainfall report of zero; days left blank have no rainfall report (which often indicates no rain fell).
Rainfalls coloured
according to the amount
0 1.0 5.0 10.0 15.0 25.0 50.0 100 150 200 300 400 600 millimetres

Notes

The Monthly 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 4 pm 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
Enquiries