Perth in January 2016: Warm nights with above average rainfall

Mean minimum temperatures were mostly 1 °C to 2 °C warmer than normal across the Perth metropolitan area in January 2016, while mean maximum temperatures were generally near average. Both rainfall and rain days were above average for the month.

  • Mostly near average maximum temperatures
  • Above average minimum temperatures
  • Above average rainfall and rain days

Across the Perth area, rainfall in January 2016 was above average, ranging from 15 mm to 30 mm on the coastal plain and offshore islands, to 40 mm to 60 mm in the hills. Rain days were also above average, ranging from 6 to 8 days on the coastal plan, to 9 to 10 days in the hills. The wettest day for most sites was the 31st as thunderstorms and a cloudband moved over the southwest, though the highest daily rainfall total recorded in the metropolitan area in January 2016 was 23.8 mm on the 26th at Mount Helena, the result of a thunderstorm that developed over the area. Perth Metro recorded a total of 15.2 mm on 8 rain days, which was above the long-term average of 9.7 mm, and the number of rain days was the equal highest in January on record, equalling 8 rain days recorded in both January 1916 and 1990. Perth also experienced an unusually high number of thunderstorms during January 2016 as Perth Airport recorded five days where thunderstorms were observed, which is well above the long-term average of one day, and the equal highest in January on record, equalling the previous record of five thunderstorm days in January 1992.

Mean maximum temperatures were in the high twenties in the hills and on the offshore islands, and in the low-thirties across the coastal plain in January. For most coastal plain sites, mean maximum temperatures were close to average, though maxima were above average on the offshore islands but below average in the hills. Days were generally warm to hot though a number of mild days were reported between the 10th and 12th, from the 18th to 20th, and on the 30th and 31st, and very hot days were reported on the 7th and 8th. The hottest day for most sites was the 7th, with inland coastal plain sites experiencing a day of 40 °C or above, and a daily maximum temperature of 43.0 °C at Perth Airport was the highest temperature of the month for the Perth metropolitan area. The coolest day was either the 18th or 31st, and Bickley recorded the lowest maximum temperature for the month in the Perth region on the 31st with a maximum of 21.2 °C. Perth Metro recorded a daily maximum temperature of 23.6 °C on the 18th, which was its coolest day in January for six years, since recording a maximum temperature of 22.6 °C on 24 January 2011.

Mean minimum temperatures were mostly 1 °C to 2 °C warmer than normal across the Perth metropolitan area, ranging from the mid-teens in the hills, to the high teens and low twenties on the coastal plain and offshore islands. Nights were mostly mild to warm, apart from a hot night on the 8th, with minima across the metropolitan area in the mid-twenties, and a number of cooler nights on the 1st, 13th and 14th, 19th to 22nd, and the 28th. Perth Metro recorded a mean minimum temperature of 19.3 °C in January 2016, which was the warmest January in terms of night-time temperatures for three years, since January 2013 when a mean minimum temperature of 19.3 °C was also recorded.

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Extremes in January 2016
Hottest day 43.0 °C at Perth Airport on the 7th
Warmest days on average 33.9 °C at Pearce RAAF
Coolest days on average 28.0 °C at Rottnest Island
29.7 °C at Bickley
Coldest day 21.2 °C at Bickley on the 31st
Coldest night 11.6 °C at Bickley on the 13th
Coolest nights on average 16.5 °C at Bickley
Warmest nights on average 20.1 °C at Gosnells City
Warmest night 28.4 °C at Gosnells City on the 8th
Warmest on average overall 26.4 °C at Pearce RAAF
Coolest on average overall 23.1 °C at Bickley
Wettest overall 59.2 mm at Mount Helena
Wettest day 23.8 mm at Mount Helena on the 26th
Strongest wind gust 87 km/h at Rottnest Island on the 31st




Summary statistics for January 2016
Maximum temperatures
(°C)
Minimum temperatures
(°C)
Rainfall
(millimetres)
Mean for
January
2016
Diff
from
average
Highest for
January
2016
Mean for
January
2016
Diff
from
average
Lowest for
January
2016
Total for
January
2016
Average
for
January
Rank of
January
2016
Fraction of
January
average
Bickley 29.7 -1.0 39.9 7th 16.5 +1.1 11.6 13th 44.6 17.9 high 249%
Garden Island HSF 29.4 +2.0 39.2 7th 20.0 +1.0 15.6 13th 26.2 10.5 high 250%
Gosnells City 32.5 -0.7 42.8 7th 20.1 +1.5 14.9 14th        
Jandakot Aero 32.0 +0.6 42.4 7th 18.7 +1.9 13.9 20th 28.2 14.2 high 199%
Karnet 30.5 -0.2 39.1 7th 16.8 +1.5 11.9 13th        
Pearce RAAF 33.9 +0.4 42.2 7th 19.0 +2.0 13.7 20th 20.2 8.9 high 227%
Perth Airport 32.4 +0.7 43.0 7th 19.0 +2.0 12.8 19th 22.6 9.6 high 235%
Perth Metro 32.0 +0.8 41.9 7th 19.3 +1.2 13.9 19th 15.2 9.7 high 157%
Rottnest Island 28.0 +1.5 38.2 8th 19.8 +0.7 15.6 20th 25.8 12.1 high 213%
Swanbourne 30.9 +1.0 39.8 7th 19.7 +1.5 14.1 19th 15.2 14.7 high 103%
Note: Observations for “Perth Metro” are taken from the current site at Mount Lawley (Bureau number 009225).
Comparisons are made against combined data from the current site (which opened in early 1993) and the previous site at Perth Regional Office (009034), which ran from 1876 to early 1992.

Daily maximum temperatures for January 2016
12345678910111213141516171819202122232425262728293031
Bickley31.033.835.030.230.635.239.932.034.523.625.422.828.131.334.035.231.721.723.122.926.228.931.733.829.431.329.931.234.322.221.2
Garden Island HSF34.032.230.127.125.832.739.238.031.325.326.622.831.434.634.536.224.622.923.523.623.227.428.228.731.128.829.335.137.224.522.8
Gosnells City34.336.538.130.335.642.836.935.726.627.831.934.536.636.932.524.526.125.629.230.335.732.033.834.034.537.626.721.6
Jandakot Aero34.435.636.832.328.933.442.438.035.326.127.126.231.234.136.038.731.323.824.925.828.928.835.435.333.832.833.434.237.126.724.6
Karnet30.433.934.433.230.036.939.129.133.924.526.123.527.731.034.035.731.822.523.223.324.329.534.233.731.131.330.631.533.5
Pearce RAAF35.338.738.134.732.637.442.239.037.327.929.329.131.834.537.838.935.024.226.027.530.032.237.538.136.434.034.637.831.526.4
Perth Airport35.036.637.431.430.234.943.037.435.525.927.626.931.434.136.738.631.323.925.925.628.430.436.036.233.933.933.834.437.426.125.3
Perth Metro35.036.036.731.527.933.541.937.734.726.427.426.031.034.236.738.731.423.626.326.727.528.934.935.633.633.133.134.437.127.024.5
Rottnest Island30.130.728.327.924.631.033.338.231.725.326.124.225.931.834.534.825.222.822.923.323.724.727.227.328.528.426.731.133.023.122.0
Swanbourne34.934.533.029.525.833.939.839.131.425.927.124.830.834.935.836.626.923.424.225.326.428.833.832.232.231.032.534.737.827.022.9
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 2016
12345678910111213141516171819202122232425262728293031
Bickley13.115.718.720.217.517.520.918.917.515.416.011.612.316.720.620.817.811.912.714.012.516.417.317.918.417.213.815.219.216.8
Garden Island HSF17.222.222.222.920.220.220.824.719.121.120.619.815.616.621.921.321.618.615.816.917.617.119.721.322.621.721.117.520.123.419.3
Gosnells City16.521.523.023.620.024.228.420.121.318.019.114.921.025.820.119.115.915.916.517.019.821.521.517.619.023.418.0
Jandakot Aero16.621.222.623.820.518.521.717.121.015.018.414.215.819.920.517.718.314.813.915.715.916.219.022.520.420.816.919.524.519.2
Karnet12.417.618.218.216.918.221.926.215.617.815.215.911.912.917.521.716.217.614.113.514.212.817.316.619.618.617.513.816.019.5
Pearce RAAF16.722.319.324.219.819.419.626.616.719.413.918.414.116.321.921.718.319.513.813.716.516.717.821.321.820.620.517.523.419.6
Perth Airport16.819.522.524.020.219.022.226.517.520.814.717.615.016.018.722.017.619.512.813.916.516.517.618.920.521.121.117.419.124.619.3
Perth Metro17.121.923.123.420.419.921.725.618.918.916.518.615.315.919.121.219.918.213.914.616.816.717.319.220.821.121.517.619.524.519.4
Rottnest Island17.221.521.321.919.019.521.024.121.019.619.119.515.816.721.223.021.017.317.115.617.917.519.921.122.221.421.417.920.723.018.6
Swanbourne17.222.222.922.820.019.220.125.320.519.918.819.514.916.221.622.620.818.514.114.816.816.818.519.822.921.221.417.719.924.419.2
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 2016
12345678910111213141516171819202122232425262728293031
Anketell - - - - - - - 0.2 0.2 - - 1.0 0.4 - - - - - 1.0 4.8 - - - - - 1.0 - - - 0.6 11.4
Bickley - 2.2 0.2 - - - -
0.2 - - - 0.8 - - - - 0.2 - 10.8 2.4 - -
5.2 0.6 - - - - 22.0
Bungendore - - - - - - - 0.2 0.8 - - 1.4 2.0 - - - - - - 2.2 0.4 - - 1.0 0.8 - 2.4 - - - 11.0
Garden Island HSF - - - - - - - - 0.2 - - - - - - - - - 0.6 4.4 0.2 - - - 0.2 - - - - - 20.6
Gidgegannup - - - - - - - 0.8 - - - - - - - - - - 2.8 14.2 - - - - 0.6 5.0 0.2 - - - 15.6
Jandakot Aero
- - - - - -
1.6 - - 0.4 - - - - - - 1.6 15.6 - - - - - - - - - - 9.0
Jarrahdale - - - - - - - - 1.4 - - 2.4 0.4 - - - - - - - - - - 6.4 - - - - - - 11.8
Karragullen North - 0.6 - - - - - 0.6 0.4 - - - 1.2 - - - - - - 4.6 0.4 - - 2.6 9.0 4.4 - - - - 14.4
Maida Vale - 2.2 - - - - - 0.6 - - - 0.4 0.8 - - - - - - 11.2 - - - 2.2 2.6 1.0 - - - - 6.0
Mount Helena






2.2









1.2 16.0 0.2


0.2 23.8



15.6
Mundaring - 0.2 - - - - - 0.8 - - - - 0.4 - - - 1.0 0.4 1.4 10.0 0.8 - - - 1.0 - - - - 0.2 17.8
Pearce RAAF - - - - - - - - - - - - - - - - 1.4 - 1.0 4.8 - - - - 2.0 0.6 - -
- 10.4
Perth Airport - 1.2 - - - - - - - - - - - - - - - - - 3.4 - - - 1.4 8.8 0.2 - - - - 7.6
Perth Metro - - - - - - - - - - - - 0.6 - - - - 1.2 0.4 0.4 - - - 1.0 4.4 0.8 - - - - 6.4
Pickering Brook
0.1




1.5








1.2
9.6 0.8

2.8 3.6 8.5



16.4
Roleystone - - - - - - - 6.3 - - - 0.9 - - - - - - - 5.0 0.1 - 1.6 - 2.8 3.1 0.4 - - 0.1 11.4
Rottnest Island - - - - - - -
0.2 - - - - - - - - 0.4 - 7.2 - - - - - - - - - - 18.0
Serpentine - - - - - - - - - - - 3.0 0.4 - - - - - - 0.2 2.0 - - 4.6 - 0.2 - - - 2.6 11.4
Swanbourne - - - - - - -
2.2 - - - 1.0 - - - - 0.2 0.4 - - - - - - 1.0 - - - - 10.4
Werribee - - - - - - - 1.2 2.4 0.2 - - - - - - - 0.2 1.2 9.4 - - - 0.6 2.6 12.2 - - - - 18.8
Whiteman Park - - - - - - - - - - - - - - - - - 0.4 - 12.4 - - - 0.6 10.0 0.6



7.0
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 lists the main features of the weather in Perth using the most timely and accurate information available on the date of publication; it will generally not be updated. Later information, including data that has had greater opportunity for quality control, will be presented in the Monthly Weather Review.

A climate summary is generally published on the first working day of each month.

This statement has been prepared based on information available at 10 am on Monday 1 February 2016. Some checks have been made on the data, but it is possible that results will change as new information becomes available.

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.

Observations for “Perth Metro” are taken from the current site at Mount Lawley (Bureau number 009225).
Comparisons are made against combined data from the current site (which opened in early 1993) and the previous site at Perth Regional Office (009034), which ran from 1876 to early 1992.

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.

The ACORN-SAT dataset is used for temperature area averages.

Further information

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(03) 9669 4057
Enquiries

Climate

Service notice

Network problems on 8 January disrupted processing of observations, affecting some climate information. Missing data are being retrieved and will be processed into our systems over coming weeks.