Greater Perth in January 2021: dry and very warm

January 2021 was dry and very warm across Greater Perth. Both mean maximum and minimum temperatures were above average. Monthly rainfall at most sites recorded less than 5 mm.

Dry with across Greater Perth

  • January 2021 was dry across Greater Perth with monthly rainfall totals of less than 5 mm at most sites, and only Araluen and Mount Solus at the Perth hills recorded more than 10 mm.
  • Isolated thunderstorms produced light rainfall on the 19th and 20th at most sites, though no rain fell in the rain gauge at Perth Airport and Jandakot Airport.
  • Perth Metro recorded a mere 0.2 mm total in January, which was its lowest January rainfall since 2014.

Above average temperatures

  • Mean maximum temperatures were about 0.5 °C above average in the Perth hills, and 1–2 °C above average for coastal plain sites, reaching 3 °C at Garden Island.
  • Mean minimum temperatures were above average at all sites, with Perth Airport and Pearce RAAF were 1.6 °C above average.
  • Perth Metro recorded a mean maximum temperature of 32.9 °C, which was its fourth-warmest January on record, and warmest since 2015.
  • The hottest day was on the 8th with temperatures in the high 30s to low 40s, and the coolest day was on the 27th with temperatures in the mid-20s.
  • Perth Metro recorded a maximum temperature of 42.2 °C on the 8th, which was its highest January temperature for 5 years since 44.4 °C was recorded on 6 January 2015.

Perth Metro

  • Total rainfall for Perth Metro was 0.2 mm, which is 1% of the long-term average of 18.5 mm
  • The mean daily maximum temperature for Perth Metro was 32.9 °C, which is 1.7 °C above the long-term average of 31.2 °C
  • The warmest day was 42.2 °C on the 8th, and the coolest day was on the 27th when the temperature reached 25.9 °C
  • The mean daily minimum temperature for Perth Metro was 18.7 °C, which is 0.6 °C above the long-term average of 18.1 °C
  • The coldest morning was 14.3 °C on the 27th, and the warmest morning was on the 9th when the minimum temperature was 23.7 °C

 

Further information

Media
(03) 9669 4057

Extremes in January 2021
Hottest day 42.3 °C at Pearce RAAF on the 8th
Warmest days on average 34.2 °C at Pearce RAAF
Coolest days on average 29.3 °C at Rottnest Island
Coldest day 23.0 °C at Garden Island HSF on the 27th
Coldest night 10.3 °C at Karnet on the 28th
Coolest nights on average 15.7 °C at Karnet
Warmest nights on average 19.8 °C at Rottnest Island
Warmest night 26.7 °C at Mandurah on the 9th
Warmest on average overall 26.4 °C at Pearce RAAF
Coolest on average overall 23.2 °C at Karnet
Wettest overall 15.0 mm at Araluen
Wettest day 15.0 mm at Araluen on the 20th
Strongest wind gust 93 km/h at Perth Airport on the 2nd

Summary statistics for January 2021
Maximum temperatures
(°C)
Minimum temperatures
(°C)
Rainfall
(millimetres)
Mean for
January
2021
Diff
from
average
Highest for
January
2021
Mean for
January
2021
Diff
from
average
Lowest for
January
2021
Total for
January
2021
Average
for
January
Rank of
January
2021
Fraction of
January
average
Bickley 31.0 +0.5 38.9 8th 15.8 +0.4 11.4 28th 2.2 20.2 average 11%
Garden Island HSF 30.4 +3.2 39.5 8th 19.2 +0.3 16.0 28th 0.8 14.1 average 6%
Jandakot Aero 33.1 +1.8 41.3 8th 18.2 +1.4 12.0 27th 0 15.8 lowest 0%
Karnet 30.6 0.0 38.4 8th 15.7 +0.4 10.3 28th 2.0 18.7 average 11%
Mandurah 31.9 +2.6 38.6 8th 19.5 +0.6 15.5 28th 1.6 16.7 average 10%
Millendon (Swan Valley) 33.7   42.1 8th 18.5   12.1 27th 5.4
Pearce RAAF 34.2 +0.7 42.3 8th 18.6 +1.6 11.5 27th 0.2 10.3 average 2%
Perth Airport 33.6 +1.8 41.5 8th 18.6 +1.6 11.7 27th 0 10.8 lowest 0%
Perth Metro 32.9 +1.7 42.2 8th 18.7 +0.6 14.3 27th 0.2 18.5 low 1%
Rottnest Island 29.3 +2.9 39.7 8th 19.8 +0.7 16.4 28th 0 15.5 lowest 0%
Swanbourne 31.3 +1.6 40.1 8th 19.4 +1.2 15.2 28th 0.4 18.8 low 2%

Daily maximum temperatures for January 2021
12345678910111213141516171819202122232425262728293031
Bickley31.929.029.029.530.632.835.538.937.026.430.031.430.630.529.830.732.831.935.529.934.535.327.825.125.225.125.230.731.532.235.5
Garden Island HSF30.032.632.032.734.235.636.239.529.423.925.623.929.734.133.333.236.935.229.427.427.828.824.226.325.023.823.028.234.434.730.7
Gosnells City35.132.533.841.637.628.232.732.734.033.536.034.236.037.135.828.928.128.635.035.5
Jandakot Aero35.232.432.232.134.036.037.841.336.127.231.030.633.933.933.534.136.335.736.831.135.133.627.627.427.226.426.433.235.035.638.2
Karnet30.728.727.629.230.733.336.038.436.426.729.831.229.131.229.430.632.733.035.230.633.434.927.224.524.925.525.029.730.932.2
Mandurah34.232.831.133.034.535.335.738.634.926.331.128.432.933.633.533.936.334.331.829.532.230.626.426.226.125.825.130.134.335.134.7
Millendon (Swan Valley)35.132.032.132.334.036.138.342.139.128.032.632.133.632.932.734.036.234.038.331.637.338.129.128.428.727.727.433.334.235.338.2
Pearce RAAF35.533.232.332.834.536.239.042.339.829.233.233.434.133.833.234.036.433.339.032.037.738.629.929.628.927.928.133.535.136.038.7
Perth Airport35.632.431.932.433.936.438.641.538.128.032.532.433.933.632.834.136.135.237.831.236.436.828.228.127.926.427.033.334.535.638.4
Perth Metro33.932.932.332.534.335.938.542.235.927.030.929.433.133.633.134.236.734.536.630.134.836.527.327.127.426.325.930.934.535.237.3
Rottnest Island26.731.230.531.132.833.135.339.729.925.424.924.526.731.032.133.335.031.231.927.026.527.726.025.025.224.824.225.428.230.731.1
Swanbourne30.532.532.132.534.036.337.340.131.625.727.725.831.534.033.334.136.334.830.027.830.331.026.026.325.924.925.028.435.036.034.6
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 January 2021
12345678910111213141516171819202122232425262728293031
Bickley16.215.713.712.913.914.618.320.424.718.112.914.013.312.713.213.614.619.221.220.118.916.019.514.514.813.512.611.414.814.916.1
Garden Island HSF19.919.518.017.318.220.220.317.722.521.117.318.116.716.617.218.420.124.323.622.422.020.719.118.018.717.317.216.018.719.219.7
Gosnells City20.418.517.619.225.921.117.018.116.517.018.219.422.020.520.716.317.417.414.017.5
Jandakot Aero19.219.117.416.517.318.621.118.423.321.215.416.316.416.216.617.718.724.324.722.421.819.616.514.116.713.512.014.518.318.519.3
Karnet16.216.014.213.114.815.419.720.623.717.612.613.712.712.013.115.820.221.419.517.815.716.413.114.413.711.510.314.615.015.8
Mandurah19.719.818.017.317.818.923.724.926.721.116.918.016.916.216.617.419.023.224.022.021.519.821.918.318.217.616.715.518.618.820.0
Millendon (Swan Valley)19.019.417.617.118.019.423.418.821.921.716.416.016.916.516.718.219.225.524.521.420.020.116.614.616.914.412.115.018.418.620.4
Pearce RAAF18.019.618.017.918.420.724.419.422.621.316.516.417.016.316.819.020.626.023.420.819.320.515.514.916.513.411.514.318.719.120.7
Perth Airport20.019.317.316.717.519.022.020.123.821.615.717.316.816.316.717.418.723.424.222.722.820.016.714.117.815.211.715.318.518.620.1
Perth Metro20.319.417.716.717.718.720.118.723.721.416.417.616.816.716.917.919.122.422.622.322.720.018.115.918.314.614.315.318.519.120.1
Rottnest Island20.319.418.217.818.620.321.923.523.420.317.419.116.917.217.218.820.324.422.820.922.021.420.219.419.117.918.016.419.319.421.3
Swanbourne19.919.518.017.318.119.723.023.124.420.716.318.116.916.817.218.419.924.623.321.822.220.718.917.018.216.716.215.218.719.220.4
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 January 2021
12345678910111213141516171819202122232425262728293031
Anketell - - - - - - - - - - - - - - - - - - - 0.2 - - - - 0.1 - 0.2 - - - -
Araluen - - - - - - - - - - - - - - - - - - - 15.0 - - - - - - - -


Bickley - - - - - - - - - - - - - - - - - - - 2.2 - - - - - - - - - - -
Bungendore - - - - - - - - - - - - - - - - - - - 5.8 0.2 - - - - - - - - - -
Chidlow - - - - - - - - - - - - - - - - - - - 1.5










Garden Island HSF - - - - - - - - - -
- - - - - - - - - - - - - 0.2 - 0.4 0.2 - - -
Gidgegannup - - - - - - - - - - - - - - - - - - - 5.4 - - - - - - - - - - -
Gosnells City - - - - - - - - - - - - - - - - - -


- - - - - - - - - -
Huntly - - - - - - - - - 0.1 - - - - - - - - - - - - - - - - - - - - -
Jandakot Aero - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Jarrahdale - - - - - - - - - - - - - - - - - - - 6.4 0.2 - - - - - - 0.2 - - -
Karnet - - - - - - - - - - - - - - - - - - - 2.0 - - - - - - - - - - -
Karragullen North - - - - - - - - - - - - - - - - - - - 1.2










Mandurah - - - - - - - - - - - -
- - - - - - 0.4 0.2 - - - - - 1.0 - - - -
Millendon (Swan Valley) - - - - - - - - - - - - - - - - - - - 5.4 - - - - - - - - - - -
Mount Solus - - - - - - - - - - - - - - - - - - - 12.2 0.2 - - - - - - - - - -
Muchea - - - - - - - - - - - - - - - - - - 1.8 3.8 - - - - - - - - - - -
Mundaring - - - - - - - - - - - - - - - - - - - 8.2










Pearce RAAF



















0.2 - - - - - - - - - -
Perth Airport - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Perth Metro - - - - - - - - - - - - -
- - - - 0.2 - - - - - - - - - - - -
Pinjarra South - - - - - - - - - - - - - - - - - - - 5.2 - - - - - - 0.6 - - - -
Rottnest Island - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Serpentine - - - - - - - - - - - - - - - - - - - 2.8 - - - - - - - - - - -
Subiaco Treatment Plant - - - - - - - - - -




















Swanbourne - - - - - - - - - - - - - - -
- - 0.4 - - - - - - - - - - - -
Tamala Park (Mindarie) - - - - - - - - - - - - - - - - - - 0.5 - - - - - - - - -


Wanneroo - - - - - - - - - - - - - - - - - - 0.1











Werribee - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
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 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 9 am on Monday 1 February 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