Australian Capital Territory in August 2020: a very wet month

August was a very wet month in the ACT. Maximum temperatures were below average, whilst minimum temperatures at low-elevation sites were above average.

Rainfall well above average in all locations

Something about temperatures

  • Maximum temperatures were below average at all sites.
  • Minimum temperatures were above average at low-elevation sites, but near average at Mount Ginini.
  • The low maximum temperatures and high minimum temperatures are typical of a wet month.

Canberra Airport

  • Total rainfall for Canberra Airport was 105.8 mm, which is 233% of the long-term average of 45.5 mm.
  • The August rainfall at Canberra Airport was the sixth-highest on record and the highest since 1998.
  • The mean daily maximum temperature for Canberra Airport was 12.8 °C, which is 0.4 °C below the long-term average of 13.2 °C, and the lowest for August since 2010.
  • The warmest day was 18.6 °C on the 29th, and the coolest day was on the 22nd when the temperature reached 7.5 °C.
  • The mean daily minimum temperature for Canberra Airport was 1.7 °C, which is 0.7 °C above the long-term average of 1.0 °C.
  • The coldest morning was -4.0 °C on the 6th, and the warmest morning was on the 16th when the minimum temperature was 7.3 °C.

Heavy rain and low-level snow

  • Heavy rain fell throughout the ACT on 8 and 9 August, with two-day totals of 50 to 90 mm, in association with a coastal low which brought flooding to regions east and north of the ACT. Minor flood warnings were issued for the Molonglo River.
  • Canberra Airport had 39.6 mm on the 9th, its fourth-heaviest August daily rainfall on record. The only three higher August daily rainfalls occurred on the three consecutive days 27, 28 and 29 August 1974.
  • Very cold conditions with snow to low levels occurred on 22 August. Snow fell in many Canberra suburbs and settled widely above 750 metres, with snowfalls continuing in the Brindabellas over the following days. Comparable snowfalls occurred in August 2019.
  • The maximum temperature of 7.5 °C at Canberra Airport on the 22nd was the lowest since July 2016.

Further information

Media
(03) 9669 4057

Extremes in August 2020
Hottest day 18.9 °C at Tuggeranong (Isabella Plains) AWS on the 30th
Warmest days on average 12.8 °C at Canberra Airport
12.8 °C at Tuggeranong (Isabella Plains) AWS
Coolest days on average 3.1 °C at Mount Ginini AWS
Coldest day -3.4 °C at Mount Ginini AWS on the 22nd
Coldest night -7.2 °C at Mount Ginini AWS on the 5th
Coolest nights on average -2.2 °C at Mount Ginini AWS
Warmest nights on average 1.7 °C at Canberra Airport
Warmest night 7.4 °C at Tuggeranong (Isabella Plains) AWS on the 9th
Warmest on average overall 7.3 °C at Canberra Airport
Coolest on average overall 0.4 °C at Mount Ginini AWS
Wettest overall 200.0 mm at Mount Ginini AWS
Driest overall 93.4 mm at Tuggeranong (Isabella Plains) AWS
Wettest day 68.0 mm at Nicholls (Gungahlin Lakes) on the 9th
Strongest wind gust 83 km/h at Mount Ginini AWS on the 28th

Record highest August daily rainfall
New record
(mm)
Old
record
Years of
record
Sutton (Uba) 59.8 on the 9th 50.4 on the 27th in 1974 51
Nicholls (Gungahlin Lakes) 68.0 on the 9th 44.0 on the 31st in 2004 23



Highest August total rainfall for at least 20 years
Observed
(mm)
Most recent
higher
Average for
August
Bruce (Australian Institute of Sport) 134.2 140.8 in 1985* 54.8
Torrens (Darke St) 105.0 132.4 in 1998 50.6
Aranda (Bindaga St) 85.2 136.0 in 1998* 52.8
Nicholls (Gungahlin Lakes) 112.8 118.1 in 1998* 56.3

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




Summary statistics for August 2020
Maximum temperatures
(°C)
Minimum temperatures
(°C)
Rainfall
(millimetres)
Mean for
August
2020
Diff
from
average
Highest for
August
2020
Mean for
August
2020
Diff
from
average
Lowest for
August
2020
Total for
August
2020
Average
for
August
Rank of
August
2020
Fraction of
August
average
Canberra Airport 12.8 -0.4 18.6 29th 1.7 +0.7 -4.0 6th 105.8 45.5 v high 233%
Mount Ginini AWS 3.1 -0.9 9.9 29th -2.2 -0.1 -7.2 5th 200.0 92.6 v high 216%
Tuggeranong (Isabella Plains) AWS 12.8 -1.3 18.9 30th 1.5 +0.6 -4.7 6th 93.4 47.9 high 195%
Note: Observations for “Canberra Airport” are taken from the current site (Bureau number 070351), which opened in late 2008.
Comparisons are made against data from the previous site Canberra Airport Comparison (070014), which ran from 1939 to 2010,
combined with the current site from March 2010 onwards.

Daily maximum temperatures for August 2020
12345678910111213141516171819202122232425262728293031
Canberra Airport13.211.814.112.39.910.810.512.411.312.611.512.616.914.711.114.913.614.311.210.710.57.510.911.012.613.915.613.718.618.415.0
Mount Ginini AWS7.98.67.2-0.10.04.4-0.31.20.97.99.32.57.15.41.71.31.51.5-0.9-0.7-0.9-3.4-1.00.11.53.31.75.59.96.46.0
Tuggeranong (Isabella Plains) AWS12.011.712.911.710.711.08.411.912.112.211.312.217.014.412.114.714.414.411.411.09.78.010.812.513.014.015.513.918.418.915.3
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 August 2020
12345678910111213141516171819202122232425262728293031
Canberra Airport-1.6-1.0-2.70.50.6-4.00.76.06.86.5-3.2-1.03.41.95.37.36.25.84.95.15.12.31.90.4-2.6-3.3-2.91.0-2.5-1.46.3
Mount Ginini AWS1.00.52.4-0.8-7.2-6.9-3.5-1.9-0.7-2.8-2.40.11.01.6-0.50.1-0.3-2.1-1.6-3.4-3.1-5.9-5.5-6.0-6.6-4.4-3.4-5.3-2.52.0-1.6
Tuggeranong (Isabella Plains) AWS-1.1-2.00.40.61.1-4.70.25.37.46.9-4.1-0.43.71.25.45.34.37.15.95.55.51.81.5-2.9-2.5-3.8-3.61.8-2.3-2.44.1
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 August 2020
12345678910111213141516171819202122232425262728293031
Aranda (Bindaga St) - - - - - 0.2 2.4 25.0 54.4 3.2
Bruce (Australian Institute of Sport) - - - - - - - 93.6 - 2.2 - - 13.0 - 0.8 12.8 - 11.8






Canberra (Australian National Botanic Ga - - - - - - 1.4 22.4 46.1 3.8 - - 1.8 - 7.4 3.6














Canberra Airport - - 0.4 - - - 1.0 19.6 39.6 5.2 0.2 - 1.8 - 11.2 2.6 - - 5.8 10.0 0.4 6.4 1.4 0.2 - - - - - - -
Canberra Parliament House - - - - - - - 65.6 - - - - 12.0 - 4.4











Ginninderra (Charnwood (ACT)) 0.2 0.2 - - - - 2.8 32.2 48.6 1.6 0.2 - 2.0 - 6.8 2.8 - 0.2 0.4 12.6 4.2 9.8 2.8 - - - 0.2 20.8 - - 0.2
Mount Ginini AWS - - - - - 0.2 0.2 26.8 23.4 6.0 - - 4.4 0.8 8.2 6.4 - 1.4 5.8 27.0 17.6 40.2 22.8 8.6 0.2 - - - - - -
Nicholls (Gungahlin Lakes) - - - - - - - 22.0 68.0 7.0 - - 2.0 - 9.8 4.0














Sutton (Uba) - - - - - - - 22.0 59.8





















Torrens (Darke St) - 0.4 - - - - - 34.4 31.8 5.2 - - 1.4 - 6.6 3.0 - - 0.6 7.6 3.0 9.8 1.0 - - - - - - - 0.2
Tuggeranong (Isabella Plains) AWS 0.2 0.2 - - - - 0.6 29.2 31.0 6.6 - - 2.2 - 5.6 2.8 - - 0.8 7.2 0.8 6.0 0.2 - - - - - - - -
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 Australian Capital Territory 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 Australian Capital Territory “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 Tuesday 1 September 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

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