Victoria in September 2020: warm days and nights; dry in the east

September rainfall was below average across most of eastern Victoria and parts of the North districts; Gippsland had very much below average rainfall with some areas experiencing their driest September on record; it was a wetter than average month in parts of Victoria's West Coast and West Central districts, and in the far north-west. Both daytime and night-time temperatures were warmer than average across most of Victoria, and much warmer than average in East Gippsland.

Drier than average in eastern Victoria

  • Averaged across the state, rainfall was 23% below the long-term mean.
  • September was drier than average across most of eastern Victoria and parts of the North districts; Gippsland had very much below average rainfall with some areas experiencing their driest September on record.
  • It was a wetter than average month in parts of Victoria's West Coast and West Central districts, and in the far north-west of the state.
  • After a mostly dry start to the month, a slow moving rain band associated with a low-pressure trough brought rainfall to most of Victoria on the 13th, with many sites in the south of the state recording daily totals above 25 mm.
  • The highest daily rainfall total in Victoria this September, 42.4 mm, was recorded at Cerberus on the 13th.
  • A cut-off low pressure system moved north of Victoria on the 19th, bringing rainfall mostly to the north-east of the state.
  • Several cold fronts associated with a complex area of low pressure crossed Victoria between the 21st and the 25th and brought widespread rainfall and snowfalls.
  • Some sites had their highest September daily rainfall on record.

Warm days and nights

  • Both daytime and night-time temperatures were warmer than average across most of Victoria.
  • Averaged across the state, mean maximum and minimum temperatures were 1.51 °C and 1.01 °C above average respectively.
  • Mean maximum temperatures were much warmer than average in most of Gippsland.
  • Mean minimum temperatures were much warmer than average in the far north-west of Victoria, central areas surrounding Melbourne, East Gippsland and in parts of Northeast districts.
  • Despite the generally mild weather, there were some cold days and nights.
  • A series of cold fronts crossed Victoria between the 21st and 25th, generating strong and gusty winds, and leaving polar air in their wake.
  • On the 25th, daytime temperatures were generally 5 to 8 °C below the September average across the state, with some sites recording late-season low maximum temperature records, and Dartmouth Reservoir had its coldest September day on record.
  • Mount Hotham saw both the lowest daytime and the lowest night-time temperature in Victoria this month, −2.9 °C on the 25th and −6.9 °C on the morning of the 26th respectively.
  • Some sites had their lowest September temperature on record.

Winds, dust and snow

  • Victoria experienced strong gusty winds on several days this September, associated with the passage of vigorous cold fronts; wind gusts of 107 km/h were recorded at Mount Hotham on the 2nd, Mount William (Grampians) on the 8th and at Wilsons Promontory Lighthouse on the 22nd; the strongest wind gust this month of 117 km/h was recorded on the 26th at Wilsons Promontory Lighthouse.
  • On the 2nd, strong winds raised a large cloud of dust in Victoria's dry north; "muddy rain" was observed in parts of central Victoria on the 3rd, as dust that had been lifted from further north was carried over the state and was brought to the surface locally by showers.
  • Widespread heavy snow fell on the 25th in the Victorian Alps and blanketed parts of the south-west and central Victoria; snow fell to the lower levels in some areas of western Victoria, including at Mount Macedon, the Otway Ranges, Ballarat, Lismore, Ararat and Mortlake.

Further information

Media
(03) 9669 4057

Extremes in September 2020
Hottest day 29.6 °C at Mildura Airport on the 18th
Warmest days on average 22.4 °C at Mildura Airport
Coolest days on average 5.0 °C at Mount Hotham
Coldest day -2.9 °C at Mount Hotham on the 25th
Coldest night -6.9 °C at Mount Hotham on the 26th
Coolest nights on average -0.3 °C at Mount Hotham
Warmest nights on average 10.4 °C at Gabo Island Lighthouse
Warmest night 19.3 °C at Mildura Airport on the 19th
Warmest on average overall 15.7 °C at Mildura Airport
Coolest on average overall 2.3 °C at Mount Hotham
Wettest overall 149.6 mm at Grampians (Mount William)
Wettest day 42.4 mm at Cerberus on the 13th
Strongest wind gust 117 km/h at Wilsons Promontory Lighthouse on the 26th

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 September daily rainfall
New record
(mm)
Old
record
Years of
record
Avalon Airport 37.0 on the 13th 35.4 on the 22nd in 1976 39
Cerberus 42.4 on the 13th 27.6 on the 12th in 2004 31
Sheoaks 31.0 on the 13th 28.2 on the 4th in 2010 27
Warrnambool Airport NDB 40.2 on the 25th 31.0 on the 11th in 2004 22
Cape Schanck 32.0 on the 13th 22.6 on the 26th in 2009 21



Record lowest September daily maximum temperature
New record
(°C)
Old
record
Years of
record
Average for
September
Dartmouth Reservoir 7.5 on the 25th 7.6 on the 5th in 2017 42 16.6



Record highest September mean daily maximum temperature
New record
(°C)
Old
record
Years of
record
Average for
September
Combienbar AWS 17.4 = 17.4 in 2013 26 15.8
Cape Nelson Lighthouse 17.8 17.7 in 2001 24 15.9



Record highest September daily minimum temperature
New record
(°C)
Old
record
Years of
record
Average for
September
Mallacoota 17.2 on the 20th 16.9 on the 21st in 2019 28 8.2



Record lowest September temperature
New record
(°C)
Old
record
Years of
record
Average for
September
Port Fairy AWS 0.4 on the 28th 1.1 on the 1st in 2015 29 8.3
Swan Hill Aerodrome -2.0 on the 1st -1.7 on the 17th in 2017 24 5.7
Mount Baw Baw -6.3 on the 28th -6.1 on the 9th in 2008 23 -0.2



Summary statistics for September 2020
Maximum temperatures
(°C)
Minimum temperatures
(°C)
Rainfall
(millimetres)
Mean for
September
2020
Diff
from
average
Highest for
September
2020
Mean for
September
2020
Diff
from
average
Lowest for
September
2020
Total for
September
2020
Average
for
September
Rank of
September
2020
Fraction of
September
average
North Mallee (district 76)
Mildura Airport 22.4 +1.8 29.6 18th 8.9 +1.6 2.1 10th 25.0 26.5 average 94%
Ouyen (Post Office)     27.6 18th 8.0 +1.3 0.5 1st 22.4 32.5 average 69%
Walpeup Research 21.4 +1.7 28.2 12th 8.1 +1.2 1.4 27th 23.4 31.1 average 75%
South Mallee (district 77)
Hopetoun Airport 20.8 +0.5 27.7 12th 6.1 +1.4 -2.1 1st 28.6 26.5 high 108%
Swan Hill Aerodrome 21.2 +0.9 27.2 8th 6.5 +0.8 -2.0 1st 15.4 25.7 average 60%
North Wimmera (district 78)
Kellalac (Warracknabeal Airport) 19.0   25.0 7th 6.0   -1.4 1st 30.8
Nhill Aerodrome 18.5 +0.1 25.7 7th 6.8 +1.1 0.8 1st 44.4 30.9 high 144%
South Wimmera (district 79)
Edenhope Airport 17.1 +0.1 25.3 7th 7.1 +0.7 0.2 10th 68.2 50.3 high 136%
Grampians (Mount William) 9.4 +0.5 17.8 18th 2.7 +0.6 -2.5 26th 149.6 117.1 high 128%
Horsham Aerodrome 17.9 -0.1 23.8 7th 5.3 +1.0 -2.2 1st 44.0 37.2 high 118%
Kanagulk 16.9 +0.4 23.2 7th 5.9 +0.4 -0.7 1st 65.6 44.2 high 148%
Longerenong 18.0 +0.7 24.4 7th 6.0 +1.0 0.7 15th
Pyrenees (Ben Nevis) 12.2 +0.3 18.6 7th 4.7 +0.6 -1.4 26th 85.4 69.1 high 124%
Stawell Aerodrome 16.8 +0.2 23.3 7th 6.8 +0.9 0.2 28th 54.6 49.9 average 109%
Lower North (district 80)
Charlton 19.5 +0.6 24.4 16th 6.8 +1.7 -1.4 1st 29.4 34.4 average 85%
Echuca Aerodrome 19.7 +1.3 24.6 16th 6.7 +0.4 -0.6 1st 22.6 38.6 low 59%
Kerang 20.8 +1.6 26.5 8th 7.6 +1.0 -0.6 1st 16.6 35.2 low 47%
Kyabram 19.1 +1.4 24.6 19th 6.6 +1.3 -0.8 1st
Upper North (district 81)
Bendigo Airport 17.8 +0.8 22.5 19th 6.1 +1.6 -1.5 1st 44.8 50.2 average 89%
Shepparton Airport 18.8 +0.6 23.7 19th 6.8 +1.4 -0.5 1st 23.0 35.7 average 64%
Tatura Inst Sustainable Ag 18.3 +0.8 23.1 19th 6.2 +0.8 -0.7 1st 24.4 42.2 average 58%
Yarrawonga 19.1 +0.5 24.8 8th 6.1 +1.1 -1.1 1st 34.6 41.9 average 83%
Lower Northeast (district 82)
Benalla Airport 18.2 +0.5 22.9 19th 5.6 +1.3 -0.2 6th 31.2 40.2 average 78%
Hunters Hill 13.2 +0.9 19.0 8th 6.0 +1.5 -1.2 26th 90.8 113.8 average 80%
Rutherglen Research 18.5 +1.3 23.8 8th 4.7 +0.6 -2.5 1st 39.2 53.6 average 73%
Strathbogie 14.9 +0.6 20.0 19th 4.6 +0.9 -3.1 1st 65.4 93.8 average 70%
Wangaratta Aero 18.7 +1.1 24.9 19th 5.0 +0.5 -1.6 1st 30.4 52.5 low 58%
Upper Northeast (district 83)
Falls Creek 6.0 +1.1 12.3 19th 0.4 +1.3 -6.6 26th 93.2 117.0 average 80%
Mount Buller 6.1 +1.2 13.1 19th 0.5 +1.3 -5.8 26th 118.0 145.4 average 81%
Mount Hotham 5.0 +1.5 11.5 19th -0.3 +1.4 -6.9 26th 81.8 126.9 low 64%
Omeo 16.0 +0.6 21.2 8th 4.2 +1.2 -4.2 28th 16.2 49.3 v low 33%
East Gippsland (district 84)
Combienbar AWS 17.4 +1.6 26.6 21st 7.5 +1.0 1.8 1st 32.8 68.6 low 48%
Gabo Island Lighthouse 16.9 +1.0 23.9 22nd 10.4 +0.7 7.4 27th 22.0 71.3 v low 31%
Gelantipy 15.4 +1.6 22.5 19th 5.4 +1.0 -1.7 1st 13.8 56.7 lowest 24%
Lakes Entrance (Eastern Beach Road) 18.0 -0.1 25.3 8th 7.4 -0.3 2.6 1st 17.4 47.7 v low 36%
Mallacoota 18.3 +0.8 26.3 21st 9.2 +1.0 4.8 10th 27.6 77.3 low 36%
Mount Nowa Nowa 17.9 +0.9 26.4 19th 8.9 +1.1 3.9 26th 24.4 60.1 lowest 41%
Orbost 19.1 +0.9 27.3 8th 8.1 +0.5 3.3 29th
West Gippsland (district 85)
Bairnsdale Airport 18.9 +1.1 25.9 20th 5.6 -0.2 0.4 1st 5.4 50.2 lowest 11%
Corner Inlet (Yanakie) 16.5   23.4 20th 8.1   1.7 29th 59.2
East Sale 18.6 +1.5 25.9 8th 5.8 +0.2 0.9 1st 12.6 49.7 v low 25%
East Sale Airport 18.8   26.0 8th 5.7   1.0 2nd 12.8
Morwell (Latrobe Valley Airport) 18.0 +1.0 25.0 8th 5.6 -0.3 -0.9 1st 40.4 73.7 v low 55%
Mount Baw Baw     14.7 19th 0.3 +0.5 -6.3 28th 78.2 155.1 low 50%
Mount Moornapa 17.2 +0.8 23.7 20th 7.7 +0.8 2.2 1st 13.8 51.5 lowest 27%
Nilma North (Warragul) 17.2   23.3 8th 7.2   -0.1 1st 58.0
Pound Creek 17.3 +0.7 23.1 2nd 7.8 +0.3 -0.2 29th 76.6 79.7 average 96%
Wilsons Promontory Lighthouse 15.6 +1.3 23.7 8th 10.2 +1.2 7.6 1st 61.0 98.4 low 62%
Yarram Airport 17.5 +0.2 24.8 20th 5.5 -0.6 -0.1 10th 35.4 49.0 low 72%
East Central (district 86)
Cerberus 17.4 +1.0 24.4 19th 8.3 +0.7 0.2 29th 88.2 67.4 high 131%
Coldstream 18.1 +0.9 25.6 19th 6.4 +0.9 -0.3 1st 65.0 69.3 average 94%
Essendon Airport 18.1 +1.3 26.0 19th 9.1 +2.3 2.6 29th 29.2 50.5 low 58%
Ferny Creek 14.4   21.9 19th 7.0   1.4 26th 74.0
Frankston (Ballam Park) 17.4   24.6 19th 9.0   3.8 29th 71.6
Melbourne (Olympic Park) 18.1   26.3 19th 9.8   4.3 29th 33.6
Melbourne Airport 17.7 +1.0 25.2 19th 8.1 +1.0 2.2 29th 27.8 46.1 low 60%
Moorabbin Airport 18.0 +1.1 26.6 19th 9.2 +1.1 2.4 29th 51.4 63.8 average 81%
Rhyll 16.9 +0.8 22.1 19th 10.1 +0.6 5.8 29th 84.4 68.5 high 123%
Scoresby Research Institute 17.9 +1.3 25.2 19th 8.4 +0.8 1.5 29th 57.0 82.2 low 69%
Viewbank 18.2 +0.5 25.3 19th 8.5 +0.8 1.6 29th 42.6 54.1 average 79%
West Central (district 87)
Avalon Airport 18.1 +0.3 26.0 19th 7.5 +0.8 1.3 1st 76.6 44.8 v high 171%
Breakwater (Geelong Racecourse) 17.8   24.4 19th 8.2   2.1 28th 84.8 52.1 high 163%
Laverton RAAF 18.0 +0.9 26.4 19th 8.5 +1.8 1.4 29th 38.4 48.2 average 80%
Sheoaks 15.4 -0.1 20.3 2nd 6.6 +0.4 -0.6 28th 70.6 48.2 high 146%
North Central (district 88)
Castlemaine Prison 16.0 +0.3 21.3 19th 6.7 +1.7 -0.1 1st 49.4 60.0 average 82%
Eildon Fire Tower 14.5 +1.0 20.7 19th 6.4 +0.7 -0.1 26th 57.6 63.3 average 91%
Lake Eildon 17.7 +1.1 24.5 19th 6.3 +0.7 -0.5 1st 76.6 81.5 average 94%
Mangalore Airport 17.6 +0.8 22.4 19th 6.0 +0.8 -1.1 1st 38.6 54.0 average 71%
Maryborough 17.3 +0.6 23.6 19th 6.5 +1.1 -0.2 1st 39.4 51.6 average 76%
Puckapunyal Lyon Hill (Defence) 17.4   22.6 19th 7.5   1.4 1st 25.0
Puckapunyal West (Defence) 16.6   21.4 19th 6.9   1.8 1st 26.8
Redesdale 17.1 +0.7 23.0 19th 5.3 +1.2 -0.9 28th 54.8 52.8 average 104%
Wallan (Kilmore Gap) 13.8 +0.6 20.7 19th 6.2 +0.6 0.2 26th 49.4 58.9 average 84%
Western Plains (district 89)
Ararat Prison 16.5 +1.2 22.2 19th 6.3 +1.2 -1.5 28th 96.0 61.2 high 157%
Ballarat Aerodrome 14.5 +0.6 21.7 19th 5.5 +0.7 -1.2 1st 64.4 71.1 average 91%
Westmere 15.7 0.0 22.4 19th 5.4 +0.6 -0.9 1st 83.8 49.7 high 169%
West Coast (district 90)
Aireys Inlet 16.4 +0.2 23.1 7th 8.6 +0.4 3.2 26th 73.2 58.3 high 126%
Cape Nelson Lighthouse 17.8 +1.9 26.5 19th 9.2 -0.2 3.9 1st 74.4 73.5 average 101%
Cape Otway Lighthouse 15.7 +0.5 22.1 7th 9.4 +0.9 4.5 28th 101.0 90.1 average 112%
Casterton 16.7 +0.5 23.8 7th 6.6 +0.6 0.7 1st 75.8 67.7 high 112%
Colac (Mount Gellibrand) 15.2 +0.7 23.1 19th 6.8 +0.3 2.8 26th
Dartmoor 17.1 +0.8 25.4 19th 7.1 +0.4 -0.6 1st 75.8 71.0 average 107%
Hamilton Airport 16.1 +0.8 23.7 19th 6.4 +0.6 0.5 28th 95.0 67.8 high 140%
Mortlake Racecourse 16.7 +0.9 24.3 19th 6.0 +0.4 -1.1 28th 94.0 58.1 high 162%
Port Fairy AWS 17.2 +0.6 26.1 19th 8.6 +0.3 0.4 28th 90.8 69.1 high 131%
Portland (Cashmore Airport) 16.1 +0.8 26.0 19th 7.6 +0.1 0.2 28th 109.2 88.0 high 124%
Warrnambool Airport NDB 16.5 +0.5 24.3 19th 6.7 0.0 0.5 28th 102.0 75.0 high 136%

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 Thursday 1 October 2020. 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