Victoria in December 2021: below average rainfall

Rainfall in December was below average for Victoria as a whole. Daytime temperatures were above average in a large area of north-west Victoria, while night-time temperatures were close to average across most of the state.

Below average rainfall

  • State-wide rainfall was 34% below the December average of 48 mm.
  • Below average rainfall was recorded across most of western and southern Victoria.
  • Large parts of the Mallee, Wimmera, Western and Central districts recorded rainfall in the lowest 10% of December totals.
  • Cape Otway Lighthouse and Warrnambool had their lowest December total rainfall since 1931, while Cape Nelson Lighthouse and Portland had their lowest December total rainfall since 1972.
  • It was wetter than average only in East Gippsland and adjacent parts of the Northeast district.
  • A slow moving low pressure trough brought thunderstorms, strong winds and heavy rainfall to parts of central Victoria on the 1st and 2nd.
  • A deep surface trough lying along the coast of New South Wales, extended into eastern Victoria, and brought showers and rain to central and eastern parts of the state, with a number of sites recording daily rainfall totals to 9am on the 10th of 50 mm or more.
  • Combienbar had its highest December daily rainfall on record on the 10th.
  • The highest daily rainfall total in Victoria this December of 83.2 mm was recorded at Mount Wellington also on the 10th.
  • A cold front and a low pressure trough that crossed Victoria on the 19th brought thunderstorms, widespread rainfall and damaging winds to the state.
  • The last ten days of the month were generally dry for most of Victoria.
  • Mallacoota had its highest total December rainfall on record, while Gabo Island Lighthouse and Combienbar had their highest total December rainfall for at least two decades.

A warm start and end of the month

  • Mean maximum temperatures were above average in most of the Mallee, Wimmera and Central districts.
  • Statewide, the mean maximum temperature was 1.07 °C warmer than the December average.
  • The month started with daytime temperatures in the mid- to high-30s across the state. Warm daytime temperatures were recorded also on the 18th, 30th and 31st; the highest temperature recorded for the month was 41.5 °C at Shepparton Airport on the 18th.
  • Night-time temperatures were close to average across most of the state.
  • The Victorian mean minimum temperature was 0.35 °C above the December average.

Thunderstorms, flash floods and hail

  • Severe thunderstorm developed in Victoria on the 1st, with the most significant impacts in the Greater Melbourne area; heavy rainfall and flash flooding occurred in the Maribyrnong where a rainfall total of 37 mm was recorded in 30 minutes. Large hail was reported in western suburbs, in Geelong and on Bellarine Peninsula.
  • A tornado was reported near Cranbourne on the 2nd.
  • A moderate flood warning was issued for the Mitchell River on the 10th.
  • Damaging winds affected most of Victoria on the 18th and 19th; the strongest wind gusts of 135 km/h were recorded at Mount Buller and Mount Hotham on the 19th.

Further information

Media
(03) 9669 4057

Extremes in December 2021
Hottest day 41.5 °C at Shepparton Airport on the 18th
Warmest days on average 32.5 °C at Walpeup Research
Coolest days on average 15.2 °C at Mount Buller
Coldest day 4.1 °C at Mount Baw Baw on the 8th
Coldest night -2.5 °C at Mount Baw Baw on the 5th
Coolest nights on average 5.9 °C at Mount Baw Baw
Warmest nights on average 15.5 °C at Mildura Airport
Warmest night 23.9 °C at Mildura Airport on the 18th
Warmest on average overall 23.9 °C at Mildura Airport
Coolest on average overall 10.6 °C at Mount Baw Baw
Wettest overall 194.8 mm at Mount Wellington
Wettest day 83.2 mm at Mount Wellington on the 10th
Strongest wind gust 135 km/h at Mount Buller on the 19th
135 km/h at Mount Hotham on the 19th

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
Combienbar AWS 68.8 on the 10th 44.0 on the 6th in 1995 28



Record highest December total rainfall
New record
(mm)
Old
record
Years of
record
Average for
December
Mallacoota 179.6 170.2 in 2018 47 73.4

Highest December total rainfall for at least 20 years
Observed
(mm)
Most recent
higher
Average for
December
Gabo Island Lighthouse 156.6 213.7 in 1970 67.5
Combienbar AWS 142.8 149.6 in 1995* 69.5

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




Record lowest December daily maximum temperature
New record
(°C)
Old
record
Years of
record
Average for
December
Combienbar AWS 10.0 on the 10th 10.1 on the 21st in 1995 28 23.3



Summary statistics for December 2021
Maximum temperatures
(°C)
Minimum temperatures
(°C)
Rainfall
(millimetres)
Mean for
December
2021
Diff
from
average
Highest for
December
2021
Mean for
December
2021
Diff
from
average
Lowest for
December
2021
Total for
December
2021
Average
for
December
Rank of
December
2021
Fraction of
December
average
North Mallee (district 76)
Mildura Airport 32.3 +1.9 38.6 31st 15.5 +0.5 8.9 9th 1.6 24.7 v low 6%
Ouyen (Post Office) 31.7 +1.4 38.4 2nd 14.3 +0.5 7.6 9th 4.4 25.1 low 18%
Walpeup Research 32.5 +2.5 39.3 31st 13.6 0.0 6.2 9th 3.6 23.9 low 15%
South Mallee (district 77)
Hopetoun Airport 31.6 +0.9 40.0 31st 12.7 -0.4 6.4 20th 3.4 28.6 low 12%
Swan Hill Aerodrome 31.4 +0.7 40.0 18th 14.1 +0.3 8.6 11th 12.2 22.0 average 55%
North Wimmera (district 78)
Kellalac (Warracknabeal Airport) 30.5   39.7 31st 11.2   6.8 8th 6.4
Nhill Aerodrome 29.5 +0.5 39.4 31st 11.2 -1.1 6.1 8th 0 26.9 v low 0%
South Wimmera (district 79)
Edenhope Airport 27.2 +0.3 39.0 31st 10.3 -0.9 4.2 3rd 4.8 35.9 v low 13%
Grampians (Mount William) 18.4 0.0 31.2 31st 7.5 -0.3 0.6 5th 10.4 56.8 low 18%
Horsham Aerodrome 29.6 +0.9 40.0 31st 9.7 -0.9 4.1 10th 6.0 23.4 v low 26%
Kanagulk 27.2 -0.1 39.7 31st 9.9 -0.8 4.4 5th 6.2 37.2 v low 17%
Longerenong 29.8 +1.9 40.7 31st 9.9 -1.3 2.9 10th 6.4 27.2 low 24%
Pyrenees (Ben Nevis) 22.1 -0.3 34.5 31st 9.5 -0.7 3.4 9th 30.0 43.9 average 68%
Stawell Aerodrome 27.2 +0.5 38.2 31st 11.0 -0.4 6.7 5th 4.6 33.0 v low 14%
Lower North (district 80)
Charlton 30.5 +0.5 39.0 31st 12.5 -0.6 7.1 5th 9.0 32.1 v low 28%
Echuca Aerodrome 30.0 +0.9 40.5 18th 12.8 -0.7 7.9 5th 20.0 29.9 average 67%
Kerang 31.1 +1.3 39.8 18th 13.9 +0.4 8.7 5th 6.2 27.2 low 23%
Kyabram 29.3 +0.9 40.6 18th 12.9 +0.3 7.4 5th 19.8 33.5 average 59%
Upper North (district 81)
Bendigo Airport 28.6 +1.0 37.8 31st 11.9 -0.1 5.2 20th 10.2 38.2 low 27%
Shepparton Airport 30.0 +0.8 41.5 18th 12.6 -0.4 8.3 20th 15.6 31.9 average 49%
Tatura Inst Sustainable Ag 27.3 -0.4 36.1 31st 12.3 -0.1 8.2 5th 31.6 34.8 average 91%
Yarrawonga 30.5 +0.2 41.2 18th 12.4 -1.0 7.3 11th 38.0 40.6 average 94%
Lower Northeast (district 82)
Benalla Airport 29.1 -0.2 38.9 30th 12.6 -0.7 8.5 20th 40.8 51.0 average 80%
Corryong Airport 28.1 -1.2 33.0 18th 12.3 +0.8 8.0 11th 57.0 62.5 average 91%
Dartmouth Reservoir 26.7 -0.3 33.6 31st 12.4 +0.6 8.5 21st 92.4 73.9 average 125%
Hunters Hill 23.0 -0.1 28.6 18th 12.3 +0.1 6.4 11th 88.6 77.6 high 114%
Rutherglen Research 30.0 +0.7 40.1 18th 10.9 -0.6 4.3 11th 59.0 44.2 high 133%
Strathbogie 25.3 +0.5 35.6 18th 8.3 -1.2 3.2 20th 55.6 58.0 average 96%
Wangaratta Aero 29.4 +0.1 38.5 18th 11.5 -0.3 6.2 11th 10.0 44.2 low 23%
Upper Northeast (district 83)
Mount Buller 15.2 +0.4 22.6 18th 7.0 +0.6 0.5 11th 75.2 99.4 average 76%
East Gippsland (district 84)
Combienbar AWS 21.2 -2.1 32.7 31st 11.2 -0.3 6.5 28th 142.8 69.5 v high 205%
Gabo Island Lighthouse 19.9 -0.1 25.5 31st 14.4 0.0 11.8 29th 156.6 67.5 v high 232%
Gelantipy 20.2 -1.3 30.8 31st 9.2 -0.5 4.1 12th 98.8 66.7 high 148%
Lakes Entrance (Eastern Beach Road) 21.2 -1.8 36.0 18th 12.1 -1.1 8.6 29th 115.9 67.2 high 172%
Mallacoota 21.4 -0.9 33.3 31st 13.4 -0.4 10.0 13th 179.6 73.4 highest 245%
Mount Nowa Nowa 20.9 -1.9 34.4 18th 11.7 -0.6 8.9 5th 114.8 80.5 high 143%
Orbost 22.3 -2.0 36.7 18th 12.2 -0.8 7.5 28th
West Gippsland (district 85)
Bairnsdale Airport 22.6 -1.2 37.0 31st 11.4 +0.1 7.1 28th 83.8 61.0 high 137%
East Sale 23.2 -0.3 36.6 31st 11.3 -0.1 5.7 5th 62.4 54.1 average 115%
East Sale Airport 23.5   37.3 31st 11.4   6.0 5th 48.4
Morwell (Latrobe Valley Airport) 24.1 -0.4 36.6 18th 10.5 -0.8 2.8 5th 41.6 65.4 low 64%
Mount Baw Baw 15.3 +0.6 24.4 31st 5.9 -0.1 -2.5 5th 84.2 134.2 low 63%
Mount Moornapa 22.2 -1.1 35.6 18th 10.9 -0.5 7.3 5th 163.8 66.5 v high 246%
Nilma North (Warragul) 23.7   36.2 31st 10.9   3.6 5th 30.0
Pound Creek 22.8 +0.1 37.6 31st 10.3 -1.2 3.3 29th 18.0 58.3 v low 31%
Wilsons Promontory Lighthouse 19.8 +0.9 32.9 18th 13.6 +0.9 10.5 9th 55.0 64.2 average 86%
Yarram Airport 23.6 -0.1 39.1 31st 9.9 -1.5 4.1 28th 25.6 52.6 low 49%
East Central (district 86)
Cerberus 23.2 +0.7 38.5 31st 11.5 -0.5 5.0 17th 19.2 52.9 v low 36%
Coldstream 25.6 +0.3 37.3 31st 9.5 -0.4 3.3 5th 21.4 57.8 low 37%
Essendon Airport 24.9 +0.3 38.7 31st 12.7 +0.7 9.2 17th 35.4 51.4 average 69%
Ferny Creek 21.4 -0.6 34.3 31st 10.4 -1.0 5.7 5th 31.0 93.2 low 33%
Frankston (Ballam Park) 23.9   37.3 31st 12.1   8.2 8th 18.6
Melbourne (Olympic Park) 24.3   37.7 31st 13.9   9.9 17th 27.0
Melbourne Airport 24.7 0.0 38.3 31st 11.7 -0.4 7.0 17th 35.6 50.3 average 71%
Moorabbin Airport 25.1 +1.1 39.1 31st 12.4 -0.3 7.7 8th 12.8 59.6 v low 21%
Rhyll 23.0 +1.0 35.8 31st 13.8 0.0 10.8 5th 16.4 44.4 v low 37%
Scoresby Research Institute 25.1 +1.0 37.9 31st 11.6 -0.3 5.8 5th 24.6 74.4 v low 33%
Viewbank 25.7 -0.1 38.9 31st 12.0 -0.8 6.2 8th 19.6 65.9 v low 30%
West Central (district 87)
Avalon Airport 24.6 +0.1 40.2 31st 11.5 -0.4 6.4 17th 25.4 29.3 average 87%
Breakwater (Geelong Racecourse) 23.5 -0.9 39.4 31st 11.8 -0.9 7.4 8th 31.4 29.9 average 105%
Laverton RAAF 24.2 +0.3 39.6 31st 12.6 +0.5 7.4 17th 40.6 45.9 average 88%
Point Cook RAAF 23.6   39.7 31st 12.3   7.6 17th 22.2
Sheoaks 23.6 -0.2 37.5 31st     4.3 5th 20.4 30.3 average 67%
North Central (district 88)
Castlemaine Prison 25.9 +0.3 35.0 18th 11.3 +0.3 4.5 20th 23.8 40.0 average 60%
Eildon Fire Tower 24.4 +0.3 34.4 18th 11.0 -0.4 5.1 5th 29.4 49.7 average 59%
Lake Eildon 27.5 +1.0 37.3 18th 11.5 +0.4 5.5 5th 35.8 57.1 average 63%
Mangalore Airport 28.3 +1.1 40.6 18th 11.6 -0.4 4.7 20th 15.8 40.0 low 40%
Maryborough 27.2 +0.5 37.9 31st 11.1 -0.3 6.4 5th 40.0 37.1 average 108%
Puckapunyal Lyon Hill (Defence) 27.4   39.6 18th 12.6   7.9 5th 28.8
Puckapunyal West (Defence) 26.4   37.6 18th 11.4   6.4 5th 14.2
Redesdale 27.8 +0.7 38.4 31st 10.0 -0.3 4.2 20th 16.8 37.1 average 45%
Wallan (Kilmore Gap) 22.0 -0.4 34.8 31st 10.0 -0.3 5.0 5th 22.4 45.8 low 49%
Western Plains (district 89)
Ballarat Aerodrome 23.6 +0.9 35.5 31st 9.3 -0.2 4.1 20th 26.4 49.8 low 53%
Westmere 26.2 +0.4 40.0 31st 8.0 -1.4 1.9 5th 13.2 39.0 v low 34%
West Coast (district 90)
Aireys Inlet 21.9 +0.4 35.7 31st 12.3 0.0 9.6 4th 21.0 38.4 low 55%
Cape Nelson Lighthouse 19.2 -0.7 29.8 31st 13.2 +0.1 10.7 8th 9.0 40.1 lowest 22%
Cape Otway Lighthouse 19.4 -0.5 30.4 13th 12.6 +0.5 9.7 24th 4.8 52.2 v low 9%
Casterton 24.6 -0.6 38.1 31st 9.8 -0.3 4.6 8th 5.6 37.8 v low 15%
Colac (Mount Gellibrand) 23.8 +0.3 38.9 31st 10.4 -0.4 6.1 5th 5.0 34.8 lowest 14%
Dartmoor 24.2 -0.6 38.0 31st 10.2 -0.7 5.5 5th 3.4 39.9 v low 9%
Hamilton Airport 25.1 +0.9 38.7 31st 9.3 -0.3 3.1 5th 7.6 42.5 v low 18%
Mortlake Racecourse 24.0 +0.4 38.8 31st 8.4 -0.9 3.1 11th 11.6 39.3 v low 30%
Port Fairy AWS 20.3 -1.0 30.4 13th 12.5 -0.1 7.4 6th 7.2 40.3 v low 18%
Portland (Cashmore Airport) 19.4 -0.9 30.0 17th 10.6 -0.4 6.1 14th 12.8 49.6 lowest 26%
Warrnambool Airport NDB 21.8 -0.8 34.1 31st 10.0 -0.2 5.0 6th 4.6 45.4 v low 10%

Notes

The Monthly climate summary, generally published on the first working day of each month, 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 10 am on Tuesday 4 January 2022. 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