Tuesday, 8 February 2022 - Annual Climate Summary for Greater Perth - Product code IDCKGC51L0
Greater Perth in 2021: wet, a very warm start and finish
Annual rainfall was above average in 2021 across Greater Perth, due to a very wet July and October. Annual mean maximum and minimum temperatures were generally close to average.
Above average rainfall across Greater Perth
- Rainfall was above average across Greater Perth, with annual rainfall totals mostly in the 800–900 mm range, to 1000–1300 mm in the Perth hills.
- Swanbourne had its highest annual rainfall on record, and a number of sites had their highest for at least 20 years.
- Perth Metro recorded a rainfall total of 892 mm in 2021, which was more than 150 mm above the annual average, and the second-highest annual rainfall on record, behind the record of 904.8 mm in 1995.
- The wettest month of the year was July across Greater Perth; Perth Metro had its second-wettest July on record with 271.4 mm, just behind the record of 278. 6 mm in July 1995.
- October was also very wet; Perth Metro had its wettest October on record with 122.8 mm at the current site, which was also the wettest October since 1965 in the Perth official records when 126.3 mm was recorded at Perth Regional Office.
Very warm January and an extreme heatwave in December
- Annual mean maximum temperatures were generally within half a degree of average for most sites.
- Annual mean minimum temperatures were close to or slightly above average at most sites.
- The start of the year (January) was very warm, and an extreme heatwave occurred at the end of the year (December).
- Perth Metro recorded 5 days in total with maximum temperatures of 40 °C or higher in December, which was the highest count of such days for any month in the Perth official records.
- During the extreme heatwave in late December, Perth Metro recorded four consecutive days with maximum temperatures of 40 °C or higher between the 25th and the 28th, which was the equal longest run in the Perth official records.
- The hottest days of the year were either the 25th or 26th of December; Rottnest Island recorded its all-time highest temperature on record with 42.5 °C and also all-time highest minimum temperature on record with 27.0 °C on the 26th.
- Perth Metro recorded its third-highest temperature on the 25th ( 42.8 °C) and second-highest temperature on the 26th (43.5 °C) for December in the Perth official records commencing in 1897.
Perth Metro
- Total rainfall for Perth Metro was 892.0 mm, which is 121% of the long-term average of 736.8 mm
- The mean daily maximum temperature for Perth Metro was 25.0 °C, which is 0.2 °C above the long-term average of 24.8 °C
- The warmest day was 43.5 °C on 26 December, and the coolest day was on 2 September when the temperature reached 13.9 °C
- The mean daily minimum temperature for Perth Metro was 13.2 °C, which is 0.3 °C above the long-term average of 12.9 °C
- The coldest morning was 1.1 °C on 26 June, and the warmest morning was on 9 December when the minimum temperature was 26.8 °C
Further information
- Media
- media@bom.gov.au (03) 9669 4057
Extremes Maps Records Summaries Important notes the top
Extremes in 2021 | |
---|---|
Hottest day | 43.7 °C at Swanbourne on 26 Dec |
Warmest days on average |
25.7 °C at Pearce RAAF |
Coolest days on average | 22.3 °C at Bickley |
Coldest day |
10.3 °C at Bickley on 1 Aug 10.3 °C at Bickley on 10 Aug |
Coldest night |
0.1 °C at Jandakot Aero on 22 Jun |
Coolest nights on average |
11.6 °C at Bickley |
Warmest nights on average | 15.8 °C at Rottnest Island |
Warmest night | 28.0 °C at Pearce RAAF on 26 Dec |
Warmest on average overall | 19.3 °C at Pearce RAAF |
Coolest on average overall | 17.0 °C at Bickley |
Wettest overall | 1384.3 mm at Huntly |
Wettest day | 77.0 mm at Huntly on 27 Jul |
Strongest wind gust | 115 km/h at Rottnest Island on 1 Aug |
Extremes Maps Records Summaries Important notes the top
Record highest annual total rainfall | |||||
---|---|---|---|---|---|
New record (mm) |
Old record |
Years of record |
Annual average |
||
Swanbourne | 951.8 | 873.0 | in 1996 | 25 | 737.1 |
Highest annual total rainfall for at least 20 years | |||||
---|---|---|---|---|---|
Observed (mm) |
Most recent higher |
Annual average |
|||
Pearce RAAF | 787.0 | 970.0 | in 1974* | 654.7 | |
Bickley | 1312.0 | 1410.3 | in 1996 | 1086.7 | |
Karnet | 1306.9 | 1509.8 | in 1991* | 1153.5 | |
Marbling | 891.8 | 909.1 | in 1992* | 756.9 | |
Perth Metro | 892.0 | 904.8 | in 1995* | 736.8 | |
Karragullen North | 1177.2 | 1189.8 | in 1981* | 1000.2 | |
Serpentine | 939.2 | 1050.5 | in 1974* | 918.6 | |
Jarrahdale | 1231.8 | 1312.2 | in 1992* | 1169.7 |
* note: there are gaps in the historical record at this site, so it is possible a higher value has gone unreported
Record highest temperature | ||||||
---|---|---|---|---|---|---|
New record (°C) |
Old record |
Years of record |
Annual average |
|||
Rottnest Island | 42.5 | on 26 Dec | 41.5 | on 26 Feb 1997 | 36 | 22.3 |
Record highest daily minimum temperature | ||||||
---|---|---|---|---|---|---|
New record (°C) |
Old record |
Years of record |
Annual average |
|||
Rottnest Island | 27.0 | on 27 Dec | 26.4 | on 28 Jan 2012 | 36 | 15.7 |
Extremes Maps Records Summaries Important notes the top
Summary statistics for 2021 | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
Maximum temperatures (°C) |
Minimum temperatures (°C) |
Rainfall (millimetres) |
||||||||||
Mean for 2021 |
Diff from average |
Highest for 2021 |
Mean for 2021 |
Diff from average |
Lowest for 2021 |
Total for 2021 |
Average annual total |
Rank of 2021 |
Fraction of annual average |
|||
Bickley | 22.3 | -0.3 | 40.3 | 26 Dec | 11.6 | +0.3 | 3.6 | 22 Jun | 1312.0 | 1086.7 | high | 121% |
Garden Island HSF | 22.9 | +0.2 | 42.5 | 26 Dec | 14.9 | -0.1 | 6.0 | 2 Aug | 833.2 | 610.4 | v high | 137% |
Jandakot Aero | 24.8 | +0.2 | 43.3 | 26 Dec | 12.4 | +0.8 | 0.1 | 22 Jun | 922.6 | 818.4 | high | 113% |
Mandurah | 41.0 | 26 Dec | 14.9 | +0.1 | 6.5 | 2 Aug | 678.4 | 649.2 | average | 104% | ||
Millendon (Swan Valley) | 25.5 | 42.9 | 26 Dec | 12.4 | 0.4 | 26 Jun | 752.2 | |||||
Pearce RAAF | 25.7 | +0.4 | 43.3 | 25 Dec | 12.8 | +0.6 | 1.4 | 22 Jun | 787.0 | 654.7 | high | 120% |
Perth Airport | 25.3 | +0.7 | 43.3 | 26 Dec | 12.7 | +0.5 | 0.5 | 22 Jun | 798.8 | 760.9 | average | 105% |
Perth Metro | 25.0 | +0.2 | 43.5 | 26 Dec | 13.2 | +0.3 | 1.1 | 26 Jun | 892.0 | 736.8 | v high | 121% |
Rottnest Island | 22.7 | +0.4 | 42.5 | 26 Dec | 15.8 | +0.1 | 7.2 | 2 Aug | 660.6 | 567.7 | high | 116% |
Swanbourne | 23.7 | -0.4 | 43.7 | 26 Dec | 14.3 | +0.3 | 5.1 | 22 Jun | 951.8 | 737.1 | highest | 129% |
Extremes Maps Records Summaries Important notes the top
Notes
The Annual climate summary, generally published on the second working day of the year, lists the main features of the weather in Greater Perth 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 Perth “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 5 pm on Monday 7 February 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
- media@bom.gov.au (03) 9669 4057
Unless otherwise noted, all maps, graphs and diagrams in this page are licensed under the Creative Commons Attribution 4.0 International Licence