Victoria in December 2020: cooler and drier than average

Victorian rainfall in December was near average to below average over much of the state, with only isolated patches of above average rainfall in the Western and Northern Country districts. Both daytime and night-time temperatures were cooler than average, particularly in the state's west.

Drier than average, heavy rain at times

  • Rainfall in December was 24% below average for Victoria as a whole.
  • December rainfall totals were below average in some areas in the state's north-west and east.
  • Above average rainfall totals were recorded in parts of the Western and Northern Country districts.
  • A cold front brought widespread light falls to Victoria on the 6th, while moderate falls were reported in the state's north-east, where some sites had daily rainfall totals of more than 20 mm.
  • A low pressure trough deepened over central Victoria on the 16th, bringing moderate to heavy rainfall to some areas in the north of the state.
  • A low pressure trough developed in western Victoria on the 21st and moved across the state, with a complex low pressure system forming off the south coast of New South Wales. The system and associated trough, which brought moisture from the tropical north, produced active cloud and widespread rainfall, with isolated moderate to heavy falls over parts of southern Victoria, where some sites recorded daily totals of more than 30 mm in the 24 hours to 9 am on the 22nd. on the 22nd of more than 30 mm.
  • Nullawarre had its highest December daily rainfall on record on the 22nd, while the highest daily rainfall total in Victoria this December of 73.6 mm, was recorded on the 23rd at Mount Baw Baw.
  • Cape Nelson Lighthouse had its highest total December rainfall on record.

Cooler than average temperatures

  • Both daytime and night-time temperatures were cooler than average for Victoria as a whole.
  • The Victorian mean maximum temperature was 0.24 °C below average.
  • After several years of very warm Decembers, it was the coolest December for Victoria as a whole since 2010.
  • Mean minimum temperatures were cooler than average across most of northern Victoria and warmer than average only in the state's far east.
  • The statewide December mean minimum temperature was 0.09 °C below average, the coolest since 2006.

Strong winds, fire and floods

  • A EF1 tornado (with peak gusts of 138-178 km/h) was reported at Horsham in western Victoria on the 7th; strong winds downed trees, damaged roofs and windows, scattering debris across roads, and cut the power supply to many houses.
  • A cold front brought light snowfalls to the Victorian Alps on the 8th.
  • A grass fire threatened Mount Cottrell, Chartwell and Truganina in Melbourne's west on the 14th. The fire grew to 110 hectares in size before it was contained.
  • The State Emergency Services received more than 100 calls for help for fallen trees, flooding and building damage caused by damaging winds and heavy rainfall associated with thunderstorms, which developed over parts of southern Victoria on the 22nd.

Further information

Media
(03) 9669 4057

Extremes in December 2020
Hottest day 39.8 °C at Swan Hill Aerodrome on the 27th
Warmest days on average 30.4 °C at Mildura Airport
Coolest days on average 13.4 °C at Mount Baw Baw
Coldest day 2.4 °C at Mount Buller on the 7th
Coldest night -1.8 °C at Mount Buller on the 8th
Coolest nights on average 4.5 °C at Mount Baw Baw
Warmest nights on average 15.3 °C at Gabo Island Lighthouse
Warmest night 24.6 °C at Walpeup Research on the 15th
Warmest on average overall 22.5 °C at Mildura Airport
Coolest on average overall 9.1 °C at Mount Baw Baw
Wettest overall 162.4 mm at Haines Junction (Mount Sabine)
Wettest day 73.6 mm at Mount Baw Baw on the 23rd
Strongest wind gust 130 km/h at Wilsons Promontory Lighthouse on the 6th

Maps
ObservedAnomalyDecile rank
Total
rainfall
Map of Rainfall totals Map of Percentage of normal rainfall Map of Rainfall deciles
Mean
daily
maximum
temperatures
Map of Mean maximum temperature Map of Anomaly in mean maximum temperature Map of Decile rank of mean maximum temperature
Mean
daily
minimum
temperatures
Map of Mean minimum temperature Map of Anomaly in mean minimum temperature Map of Decile rank of mean minimum temperature

Click on a map to show it full size in a pop-up window


Record highest December daily rainfall
New record
(mm)
Old
record
Years of
record
Nullawarre 71.0 on the 22nd 70.2 on the 8th in 2010 122



Record highest December total rainfall
New record
(mm)
Old
record
Years of
record
Average for
December
Cape Nelson Lighthouse 102.8 95.2 in 2010 26 41.3



Summary statistics for December 2020
Maximum temperatures
(°C)
Minimum temperatures
(°C)
Rainfall
(millimetres)
Mean for
December
2020
Diff
from
average
Highest for
December
2020
Mean for
December
2020
Diff
from
average
Lowest for
December
2020
Total for
December
2020
Average
for
December
Rank of
December
2020
Fraction of
December
average
North Mallee (district 76)
Mildura Airport 30.4 0.0 39.6 27th 14.6 -0.4 7.9 8th 8.6 25.0 average 34%
Ouyen (Post Office) 29.5 -0.9 39.6 27th 13.1 -0.7 6.4 8th 9.4 25.3 average 37%
Walpeup Research 29.8 -0.2 39.4 27th 12.6 -1.1 5.8 8th 13.2 24.2 average 55%
South Mallee (district 77)
Hopetoun Airport 29.1 -1.7 38.7 27th 11.5 -1.7 4.3 2nd 7.4 30.1 average 25%
Swan Hill Aerodrome 29.7 -1.1 39.8 27th 12.9 -0.9 6.2 2nd 27.0 22.4 average 121%
North Wimmera (district 78)
Kellalac (Warracknabeal Airport) 27.9   38.3 15th 10.5   4.8 9th 12.6
Nhill Aerodrome 26.6 -2.6 37.5 14th 11.0 -1.3 3.8 11th 32.4 28.4 high 114%
South Wimmera (district 79)
Edenhope Airport 24.0 -3.1 36.9 14th 10.3 -0.9 3.6 28th 15.8 37.8 low 42%
Grampians (Mount William) 15.7 -2.9 26.7 14th 5.7 -2.3 0.9 7th 59.7
Horsham Aerodrome 26.7 -2.1 37.8 15th 9.7 -1.0 3.3 25th 11.6 24.1 low 48%
Kanagulk 24.4 -3.1 37.5 14th 9.9 -0.9 3.9 29th 26.2 39.1 average 67%
Longerenong 27.1 -0.8 38.3 15th 9.7 -1.5 3.2 9th 15.6 27.3 average 57%
Pyrenees (Ben Nevis) 20.0 -2.6 30.8 15th 8.0 -2.4 3.2 8th 42.4 44.8 average 95%
Stawell Aerodrome 24.5 -2.3 35.0 14th 10.7 -0.8 4.8 29th 17.6 34.1 low 52%
Lower North (district 80)
Charlton 28.1 -2.0 35.9 27th 11.8 -1.4 6.0 9th 18.6 33.5 average 56%
Echuca Aerodrome 28.6 -0.5 38.2 27th 11.6 -1.9 6.6 3rd 24.5 29.9 average 82%
Kerang 29.0 -0.8 39.7 27th 13.1 -0.4 7.2 8th 47.4 27.4 high 173%
Kyabram 28.6 +0.2 38.3 27th 11.7 -1.0 6.0 8th 27.0 33.8 average 80%
Upper North (district 81)
Bendigo Airport 26.4 -1.2 35.6 15th 10.6 -1.4 3.9 2nd 23.0 39.2 average 59%
Shepparton Airport 28.6 -0.6 38.4 27th 11.9 -1.1 6.3 8th 19.6 32.5 average 60%
Tatura Inst Sustainable Ag 27.0 -0.7 37.3 27th 11.5 -0.9 7.3 9th 19.0 34.8 average 55%
Yarrawonga 29.9 -0.4 38.5 27th 12.3 -1.2 6.4 8th 14.2 40.7 low 35%
Lower Northeast (district 82)
Benalla Airport 27.3 -2.1 35.0 15th 11.9 -1.5 6.5 9th 31.7 51.7 low 61%
Dartmouth Reservoir 26.3 -0.7 33.2 27th 11.2 -0.6 5.4 8th 69.0 73.7 average 94%
Hunters Hill 22.4 -0.8 28.1 27th 11.0 -1.2 3.0 8th 63.4 77.2 average 82%
Rutherglen Research 29.6 +0.3 37.4 27th 9.6 -1.9 2.2 3rd 24.8 44.1 average 56%
Strathbogie 23.9 -0.9 31.7 27th 7.8 -1.8 2.9 5th 61.2 58.0 average 106%
Wangaratta Aero 28.8 -0.6 36.3 27th 10.4 -1.5 4.5 9th 18.2 45.2 average 40%
Upper Northeast (district 83)
Falls Creek 14.4 -1.0 20.9 15th 5.0 -1.6 -1.4 8th 127.4 108.1 average 118%
Mount Buller 14.2 -0.6 21.4 15th 5.3 -1.1 -1.8 8th 69.0 100.1 average 69%
Omeo 24.1 -0.4 35.6 15th 8.4 -0.8 2.3 12th 44.2 61.7 average 72%
East Gippsland (district 84)
Combienbar AWS 21.9 -1.5 34.1 1st 10.9 -0.6 5.9 11th 64.0 66.5 average 96%
Gabo Island Lighthouse 20.4 +0.4 24.5 15th 15.3 +0.9 10.8 8th 91.8 66.9 high 137%
Gelantipy 20.6 -1.0 30.5 15th 8.7 -1.0 1.6 19th 36.2 65.5 low 55%
Lakes Entrance (Eastern Beach Road) 21.2 -1.9 33.5 27th 12.6 -0.7 7.4 11th 74.2 63.7 average 116%
Mallacoota 21.9 -0.5 30.0 15th 14.6 +0.8 7.8 12th 66.8 71.1 average 94%
Mount Nowa Nowa 22.0 -0.8 34.3 1st 11.7 -0.6 7.4 11th 70.6 79.1 average 89%
Orbost 23.4 -0.9 34.9 1st 12.4 -0.6 5.8 11th 60.4 66.9 average 90%
West Gippsland (district 85)
Bairnsdale Airport 23.2 -0.7 35.1 15th 11.0 -0.4 5.1 11th 94.0 60.4 high 156%
Corner Inlet (Yanakie) 20.7   32.0 15th 11.4   3.2 11th 53.8
East Sale 23.3 -0.2 36.0 15th 11.5 +0.1 6.8 11th 54.6 54.0 average 101%
East Sale Airport 23.7   36.4 15th 11.6   6.7 11th 58.6
Morwell (Latrobe Valley Airport) 24.0 -0.5 35.3 15th 10.6 -0.7 3.9 11th 33.4 66.0 low 51%
Mount Baw Baw 13.4 -1.3 23.1 15th 4.5 -1.5 -1.0 2nd 152.0 136.8 high 111%
Mount Moornapa 22.6 -0.7 34.6 15th 10.5 -1.0 6.5 19th 62.4 62.9 average 99%
Nilma North (Warragul) 22.5   33.7 15th 10.3   4.3 3rd 51.2
Pound Creek 21.4 -1.4 31.4 14th 10.6 -0.9 1.0 11th 86.6 61.2 high 142%
Wilsons Promontory Lighthouse 18.8 -0.1 30.1 14th 13.2 +0.5 10.0 8th 92.0 64.3 high 143%
Yarram Airport 23.0 -0.7 36.5 15th 10.1 -1.4 1.7 11th 35.4 54.5 low 65%
East Central (district 86)
Cerberus 21.6 -0.9 33.6 14th 11.8 -0.2 5.0 3rd 54.2 53.9 average 101%
Coldstream 24.3 -1.1 34.9 15th 9.1 -0.8 3.2 29th 45.8 59.2 average 77%
Essendon Airport 23.8 -0.8 35.0 15th 12.1 +0.1 8.0 11th 29.8 51.6 average 58%
Ferny Creek 19.6   31.0 15th 9.6   6.1 3rd 117.2 99.4 high 118%
Frankston (Ballam Park) 22.5   33.0 14th 12.0   8.1 11th 64.6
Melbourne (Olympic Park) 22.9   33.7 14th 13.1   9.0 29th 42.0
Melbourne Airport 23.8 -0.9 35.0 15th 11.2 -0.9 6.8 3rd 30.8 50.6 average 61%
Moorabbin Airport 22.8 -1.2 34.3 14th 11.9 -0.9 7.0 29th 54.4 60.3 average 90%
Rhyll 21.6 -0.4 32.2 14th 13.3 -0.5 10.1 3rd 40.4 45.4 average 89%
Scoresby Research Institute 23.8 -0.4 34.4 15th 11.1 -0.8 5.6 29th 52.2 75.1 average 70%
Viewbank 24.4 -1.5 35.4 15th 11.6 -1.2 6.9 3rd 38.8 68.0 low 57%
West Central (district 87)
Avalon Airport 23.1 -1.5 35.4 14th 11.3 -0.6 6.4 29th 37.2 29.4 average 127%
Breakwater (Geelong Racecourse) 22.4   34.7 14th 11.7   6.7 3rd 38.6 29.8 high 130%
Laverton RAAF 23.1 -0.8 35.1 15th 11.9 -0.2 7.3 20th 22.6 45.9 low 49%
Sheoaks 22.5 -1.4 33.5 15th 9.4 -1.1 3.6 20th 43.8 30.6 high 143%
North Central (district 88)
Eildon Fire Tower 23.3 -0.8 32.1 15th 9.8 -1.7 5.2 8th 37.0 50.5 average 73%
Lake Eildon 26.2 -0.4 35.0 15th 10.4 -0.7 5.2 3rd 43.1 57.2 average 75%
Mangalore Airport 27.0 -0.2 37.9 27th 10.6 -1.4 4.6 8th 19.4 40.4 low 48%
Maryborough 25.3 -1.4 33.9 15th 10.6 -0.8 6.6 26th 33.0 37.0 average 89%
Puckapunyal Lyon Hill (Defence) 26.0   35.9 27th 11.8   7.1 8th 24.4
Puckapunyal West (Defence) 25.0   35.4 27th 10.9   6.6 8th 0.6
Redesdale 26.1 -1.1 35.8 15th 9.0 -1.4 3.9 2nd 24.8 37.3 average 66%
Wallan (Kilmore Gap) 21.6 -0.9 31.3 27th 9.3 -1.1 4.9 28th 34.0 46.6 average 73%
Western Plains (district 89)
Ararat Prison 24.0 -0.9 34.5 15th 9.9 +0.5 3.1 19th 53.0 38.1 high 139%
Ballarat Aerodrome 21.4 -1.3 33.8 15th 9.0 -0.5 3.8 2nd 38.0 50.0 average 76%
Westmere 22.9 -3.1 35.1 14th 8.7 -0.7 1.9 3rd 28.6 40.7 average 70%
West Coast (district 90)
Aireys Inlet 20.3 -1.2 35.5 14th 11.8 -0.5 7.3 3rd 40.4 39.0 average 104%
Cape Nelson Lighthouse 18.9 -1.1 34.7 14th 12.7 -0.4 6.0 3rd 102.8 41.3 highest 249%
Cape Otway Lighthouse 19.1 -0.8 33.0 14th 12.2 +0.1 7.1 3rd 54.4 52.5 average 104%
Casterton 21.6 -3.8 35.0 14th 9.3 -0.9 1.7 28th 62.0 39.8 high 156%
Colac (Mount Gellibrand) 21.2 -2.4 33.5 14th 10.1 -0.8 5.6 3rd 46.4 36.2 high 128%
Dartmoor 21.7 -3.3 36.6 14th 10.5 -0.4 2.9 3rd 50.0 43.0 average 116%
Hamilton Airport 21.6 -2.7 35.3 14th 9.1 -0.5 3.4 3rd 47.8 43.4 high 110%
Mortlake Racecourse 21.3 -2.4 34.2 14th 8.8 -0.5 1.6 28th 42.6 40.3 average 106%
Port Fairy AWS 20.3 -1.0 36.5 14th 12.1 -0.5 4.6 3rd 84.6 41.5 high 204%
Portland (Cashmore Airport) 19.2 -1.2 34.3 14th 10.7 -0.3 2.7 3rd 82.8 50.5 high 164%
Warrnambool Airport NDB 20.1 -2.6 34.9 14th 10.0 -0.3 3.8 26th 70.8 47.2 high 150%

Notes

The Monthly climate summary lists the main features of the weather in Victoria 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 statement has been prepared based on information available at 9 am on Tuesday 5 January 2021. 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

Climate