Wednesday, 30 November 2011 - Monthly Climate Summary for Perth - Product code IDCKGC11L0
Perth in November 2011: Warmer than normal nights
- Rainfall: Average to above average.
- Maximum temperature: Average for most sites but below average in the hills.
- Minimum temperature: Above average for most sites.
Details Extremes Records Summaries Important notes the top
Rainfall
Rainfall across the Perth metropolitan area during November 2011 was near average to above average for most of the region. Rainfall totals were generally in the 20 to 70 mm range, and Mundaring in the Perth hills received 72.6 mm, which was more than double its long-term average for November, and the highest monthly rainfall in the Perth area for the month.
Across Perth, wet conditions occurred mainly in the first half of the month, and the second half of the month saw lengthy dry spells interspersed with a couple of days of rain. A trough near the west coast combined with a middle level disturbance to produce the first widespread light to moderate rainfall across the Perth metropolitan area on the 3rd. Rain continued when a number of cold fronts followed by an unstable onshore airflow impacted the Perth region between the 4th and 8th. Daily rainfall of 34.0 mm at Mundaring on the 8th was the highest daily rainfall in the Perth area for the month.
Perth Metro recorded 29.0 mm on 8 rain days in November 2011, compared to the long-term average of 22.1 mm on 6 rain days. November rainfall totals have ranged from nil in 1891 to 73.2 mm in 1984 at Perth Metro, whilst last November (2010), Perth Metro recorded 11.6 mm on 6 rain days.
Perth Metro has recorded 785.0 mm of rainfall on 103 rain days for the year so far (January - November 2011). Though this is below the average of 837.2 mm for the January to November period, it has been the wettest such period since 796.2 mm was recorded on 110 rain days in January to November 2008.
Maximum temperature
Mean maximum temperatures were near average for most sites, though Bickley in the Perth hills was below average. Mean maximum temperatures were in the 23 to 27 °C range.
Most sites experienced three consecutive hot days (a hot day in Perth is when the daily maximum temperature is 32 °C or higher) between the 22nd and 24th, as a high pressure system moved slowly south of the state into the Bight directing dry and hot northeasterly winds over the Perth region. The 24th was the hottest day of the month with daily maxima across Perth mainland sites climbing to the mid-to-high 30s, more than 10 °C warmer than the November average.
Perth Metro's mean daily maximum temperature in November 2011 was 25.9 °C, which was close to the November average of 26.4 °C, but was the coolest November since a mean of 23.6 °C was recorded in November 2008. Daily maxima in November 2011 ranged from a mild 21.5 °C on the 8th, to a very hot 37.2 °C on the 24th. Last November (2010) was the warmest November on record at Perth Metro, since records commenced in 1897, with a mean maximum temperature of 29.6 °C.
Perth Metro's mean daily maximum temperature for the first 11 months of 2011 is 25.3 °C, the warmest January to November period since records commenced in 1897. The previous record was 24.9°C in 2010, whilst the average for the same period is 24.1 °C. This year so far, Perth Metro has also registered its greatest number of hot days on record with 67 days (32 °C or higher), exceeding the previous annual record of 66 hot days set in 1978. The annual average is 49 hot days. To reinforce the fact that Perth Metro has been experiencing unusually warm conditions over the past year or so, November 2011 was the first month to see a below average mean maximum temperature at Perth Metro since July 2010. All months since that time have been equal to or above the long-term monthly average.
Minimum temperature
Mean minimum temperatures in November 2011 were above average for most sites, and generally in the range of 13 to 16 °C .
Nights were mostly mild during November with a number of warm nights recorded (a warm night in Perth is when a daily minimum temperature is 20 °C or higher). The warmest night was the 24th for most sites with daily minima in the low-to-mid 20s. Pearce RAAF registered a minimum of 24.0 °C on the 24th, the highest overnight temperature of the month in the Perth area.
Perth Metro's mean daily minimum temperature in November 2011 was 14.9 °C, which is close to the average of 14.2 °C. Daily minima ranged from a mild 10.2 °C on the 10th to a warm 20.5 °C on the 3rd. Last November (2010) Perth Metro recorded a mean minimum temperature of 15.3 °C.
During the January to November period, Perth Metro has recorded 42 warm nights (20 °C or higher), which is the greatest number of warm nights recorded at Perth Metro for 23 years, since 52 warm nights were recorded in 1988.
Wind and Sunshine
The greatest wind gust during the month in the Perth metropolitan area was 74 km/h recorded at Rottnest Island on the 8th when a cold front passed through the Perth area.
Perth recorded an average daily sunshine of 10.2 hours per day in November 2011, the least sunshine hours for November since a daily average of 9.9 hours was recorded in 2006. The average daily sunshine hours for November is 10.7 hours.
Further information
Western Australia Climate Services CentreBureau of Meteorology
Phone (08) 9263 2222
Email climate.wa@bom.gov.au
| Extremes in November 2011 | |
|---|---|
| Hottest day | 38.7 °C at Medina Research Centre on the 24th |
| Warmest days on average | 26.6 °C at Gosnells City |
| Coolest days on average | 23.0 °C at Rottnest Island |
| Coldest day | 16.9 °C at Bickley on the 8th |
| Coldest night | 7.2 °C at Jandakot Aero on the 19th |
| Coolest nights on average | 12.3 °C at Bickley |
| Warmest nights on average | 16.7 °C at Rottnest
Island 15.5 °C at Swanbourne |
| Warmest night | 24.0 °C at Pearce RAAF on the 24th |
| Wettest overall | 72.6 mm at Mundaring |
| Wettest day | 34.0 mm at Mundaring on the 8th |
| Highest wind gust | 74 km/h at Rottnest Island on the 8th |
s Extremes Records Summaries Important notes the top
| Summary statistics for November 2011 | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Maximum temperatures for November (°C) |
Minimum temperatures for November (°C) |
Rainfall for November (millimetres) |
||||||||||
| Mean for November 2011 |
Diff from average |
Highest for November 2011 |
Mean for November 2011 |
Diff from average |
Lowest for November 2011 |
Total for November 2011 |
Average for November |
Rank of November 2011 |
Fraction of November average |
|||
| Bickley | 23.5 | -1.4 | 34.0 | 24th | 12.3 | +0.6 | 8.5 | 30th | 64.6 | 41.9 | high | 154% |
| Champion Lakes | 24.9 | 35.1 | 24th | 14.9 | 10.6 | 9th | ||||||
| Garden Island HSF | 24.0 | +0.2 | 36.9 | 24th | 16.4 | +0.8 | 12.9 | 30th | 14.2 | 24.0 | low | 59% |
| Gosnells City | 26.6 | -0.8 | 38.2 | 24th | 14.5 | +0.2 | 10.3 | 28th | 44.8 | 28.7 | high | 156% |
| Jandakot Aero | 25.7 | -0.5 | 37.3 | 24th | 13.8 | +1.4 | 7.2 | 19th | 31.6 | 29.0 | average | 109% |
| Medina Research Centre | 26.0 | +0.1 | 38.7 | 24th | 14.7 | +1.4 | 9.1 | 19th | 24.2 | 32.1 | average | 75% |
| Pearce RAAF | 26.2 | -0.9 | 37.8 | 24th | 13.6 | +1.1 | 8.4 | 10th | 29.2 | 23.4 | average | 125% |
| Perth Airport | 26.1 | +0.3 | 37.2 | 24th | 14.1 | +1.4 | 9.1 | 10th | 39.4 | 26.1 | high | 151% |
| Perth Metro | 25.9 | -0.5 | 37.2 | 24th | 14.9 | +0.8 | 10.2 | 10th | 29.0 | 22.1 | high | 131% |
| Rottnest Island | 23.0 | 0.0 | 32.2 | 23rd | 16.7 | +0.9 | 13.4 | 9th | 19.4 | 17.2 | average | 113% |
| Swanbourne | 25.5 | +0.3 | 36.0 | 24th | 15.5 | +0.9 | 10.9 | 19th | 35.2 | 23.9 | high | 147% |
Details Extremes Records Summaries Important notes the top
| Daily maximum temperature | ||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Central Coast (09) | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 |
| Bickley | 28.0 | 30.1 | 25.2 | 19.7 | 19.7 | 19.1 | 19.7 | 16.9 | 19.1 | 21.1 | 23.8 | 21.9 | 20.8 | 21.1 | 23.7 | 22.4 | 20.8 | 20.0 | 23.7 | 26.3 | 27.4 | 29.1 | 32.9 | 34.0 | 27.5 | 23.8 | 20.9 | 19.4 | 22.2 | |
| Champion Lakes | 30.3 | 25.9 | 21.8 | 21.5 | 20.9 | 21.4 | 20.1 | 20.7 | 22.6 | 25.4 | 23.0 | 22.0 | 22.5 | 24.7 | 23.4 | 22.7 | 21.8 | 25.7 | 27.4 | 29.7 | 31.7 | 34.9 | 35.1 | 27.7 | 24.7 | 23.5 | 21.7 | 24.2 | ||
| Garden Island HSF | 30.5 | 31.8 | 25.4 | 23.0 | 21.9 | 22.4 | 22.6 | 20.2 | 22.0 | 22.9 | 20.8 | 22.2 | 23.9 | 23.5 | 19.4 | 22.7 | 23.5 | 20.1 | 21.2 | 24.2 | 24.5 | 31.5 | 32.6 | 36.9 | 23.7 | 20.9 | 20.5 | 21.4 | 20.3 | |
| Gosnells City | 34.7 | 27.9 | 23.5 | 23.0 | 22.3 | 23.0 | 20.6 | 22.8 | 24.5 | 26.2 | 24.7 | 23.8 | 24.7 | 26.1 | 25.3 | 24.2 | 23.5 | 27.0 | 26.4 | 30.8 | 33.6 | 37.4 | 38.2 | 29.5 | 26.1 | 22.8 | 25.8 | |||
| Jandakot Aero | 31.3 | 33.5 | 25.9 | 23.5 | 22.3 | 21.4 | 22.6 | 20.9 | 21.9 | 22.8 | 24.3 | 23.4 | 23.1 | 23.7 | 24.1 | 23.2 | 24.9 | 22.3 | 25.7 | 28.0 | 29.5 | 32.0 | 36.1 | 37.3 | 27.2 | 25.0 | 23.7 | 22.2 | 24.6 | |
| Medina Research Centre | 31.7 | 34.2 | 27.2 | 23.2 | 22.6 | 23.2 | 23.5 | 22.3 | 23.1 | 24.4 | 23.5 | 23.3 | 24.0 | 24.0 | 23.8 | 23.7 | 25.4 | 22.3 | 24.7 | 27.6 | 29.3 | 32.9 | 36.3 | 38.7 | 27.0 | 23.8 | 23.5 | 22.0 | 23.9 | |
| Pearce RAAF | 32.0 | 25.7 | 22.9 | 23.5 | 22.6 | 23.4 | 21.2 | 22.5 | 23.5 | 25.7 | 24.6 | 23.7 | 24.2 | 26.5 | 24.9 | 25.6 | 23.2 | 26.5 | 29.2 | 30.3 | 32.5 | 35.6 | 37.8 | 24.2 | 23.0 | 25.1 | ||||
| Perth Airport | 31.0 | 33.9 | 26.1 | 22.9 | 22.6 | 21.9 | 22.7 | 20.8 | 21.8 | 23.3 | 25.4 | 24.3 | 22.9 | 24.1 | 25.6 | 23.9 | 24.1 | 22.9 | 26.2 | 28.9 | 29.4 | 32.4 | 35.9 | 37.2 | 28.4 | 25.7 | 24.1 | 22.6 | 25.0 | |
| Perth Metro | 31.2 | 33.4 | 23.8 | 23.9 | 22.6 | 22.2 | 22.6 | 21.5 | 22.0 | 23.6 | 24.7 | 23.6 | 22.8 | 24.2 | 24.5 | 23.9 | 24.0 | 22.6 | 25.5 | 28.2 | 29.5 | 33.0 | 36.3 | 37.2 | 28.0 | 24.7 | 23.5 | 22.7 | 24.3 | |
| Rottnest Island | 25.3 | 30.5 | 22.0 | 21.8 | 20.8 | 20.5 | 21.5 | 19.9 | 21.0 | 21.5 | 21.7 | 21.5 | 21.8 | 22.5 | 20.3 | 21.5 | 22.8 | 20.4 | 20.8 | 23.3 | 22.6 | 29.1 | 32.2 | 32.0 | 24.5 | 22.0 | 20.6 | 21.1 | 20.1 | |
| Swanbourne | 32.1 | 33.6 | 25.4 | 24.1 | 21.6 | 22.0 | 22.4 | 21.0 | 22.3 | 23.0 | 23.3 | 23.0 | 22.9 | 23.9 | 23.8 | 22.7 | 23.9 | 21.9 | 24.4 | 28.4 | 27.5 | 33.5 | 35.5 | 36.0 | 26.1 | 23.7 | 24.0 | 22.4 | 24.3 | |
This table is very wide; you may have to scroll sideways to see all the days, and you may need to set the paper to 'landscape' to print.
| The temperatures in this table are coloured by 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 difference from average |
Details Extremes Records Summaries Important notes the top
| Daily minimum temperature | ||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Central Coast (09) | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 |
| Bickley | 12.1 | 15.4 | 17.5 | 15.1 | 12.0 | 12.2 | 11.5 | 12.2 | 8.8 | 10.6 | 10.8 | 11.0 | 13.5 | 14.0 | 9.0 | 11.2 | 13.8 | 10.5 | 9.0 | 9.9 | 11.3 | 12.3 | 16.8 | 18.2 | 17.7 | 13.8 | 11.1 | 9.7 | 9.7 | 8.5 |
| Champion Lakes | 16.6 | 20.1 | 17.4 | 15.3 | 15.0 | 13.9 | 15.9 | 10.6 | 10.8 | 13.4 | 12.1 | 16.0 | 17.8 | 12.0 | 11.6 | 16.2 | 13.4 | 11.9 | 13.5 | 14.9 | 16.5 | 21.3 | 21.7 | 19.3 | 14.3 | 14.1 | 12.3 | 12.6 | 12.7 | |
| Garden Island HSF | 16.9 | 20.4 | 21.0 | 17.9 | 17.5 | 17.8 | 16.0 | 16.2 | 14.2 | 16.5 | 14.7 | 16.0 | 17.9 | 18.5 | 13.3 | 13.7 | 18.4 | 15.7 | 13.0 | 13.4 | 15.0 | 16.7 | 18.9 | 19.7 | 19.8 | 16.7 | 14.5 | 16.0 | 13.8 | 12.9 |
| Gosnells City | 16.5 | 20.5 | 17.5 | 15.0 | 14.5 | 12.6 | 15.5 | 10.4 | 12.4 | 11.6 | 14.8 | 14.6 | 11.4 | 11.4 | 13.5 | 12.8 | 11.5 | 14.0 | 15.4 | 16.6 | 18.2 | 21.4 | 19.7 | 14.5 | 10.3 | 12.5 | 12.8 | |||
| Jandakot Aero | 15.9 | 20.4 | 20.5 | 16.6 | 12.9 | 13.8 | 15.1 | 16.0 | 10.2 | 9.2 | 9.0 | 12.0 | 15.8 | 17.5 | 8.5 | 9.3 | 17.0 | 10.1 | 7.2 | 12.9 | 14.6 | 16.2 | 16.7 | 17.4 | 16.7 | 13.9 | 13.5 | 11.8 | 12.0 | 12.3 |
| Medina Research Centre | 15.8 | 20.1 | 21.0 | 17.4 | 15.1 | 15.3 | 16.0 | 15.7 | 10.4 | 10.6 | 11.0 | 13.0 | 17.9 | 18.4 | 11.1 | 10.7 | 17.7 | 11.5 | 9.1 | 12.8 | 13.1 | 16.5 | 18.5 | 19.5 | 18.1 | 15.1 | 14.0 | 12.5 | 12.0 | 12.2 |
| Pearce RAAF | 21.2 | 17.0 | 12.7 | 13.0 | 12.4 | 14.8 | 9.5 | 8.4 | 9.1 | 11.4 | 13.3 | 16.0 | 10.0 | 8.8 | 13.3 | 12.8 | 9.8 | 13.1 | 14.7 | 15.9 | 17.6 | 24.0 | 16.2 | 12.7 | 12.6 | 12.7 | ||||
| Perth Airport | 16.0 | 18.9 | 20.8 | 16.7 | 12.5 | 13.6 | 11.4 | 15.3 | 10.5 | 9.1 | 10.1 | 12.3 | 16.7 | 18.3 | 10.0 | 9.4 | 13.6 | 11.9 | 10.8 | 13.7 | 15.2 | 16.2 | 16.2 | 18.7 | 16.7 | 14.8 | 14.9 | 13.2 | 12.7 | 12.4 |
| Perth Metro | 15.9 | 19.9 | 20.5 | 17.6 | 13.9 | 13.2 | 15.8 | 15.2 | 11.2 | 10.2 | 11.2 | 13.8 | 17.1 | 18.5 | 10.5 | 11.8 | 15.3 | 12.9 | 11.2 | 13.8 | 15.0 | 16.5 | 17.7 | 20.0 | 19.1 | 15.4 | 15.2 | 13.7 | 13.4 | 12.5 |
| Rottnest Island | 17.2 | 19.9 | 20.8 | 18.1 | 16.6 | 16.7 | 15.9 | 15.8 | 13.4 | 15.3 | 16.0 | 16.2 | 16.9 | 18.2 | 14.6 | 16.1 | 17.8 | 16.3 | 13.7 | 14.4 | 15.7 | 17.6 | 20.1 | 21.4 | 19.7 | 17.2 | 14.8 | 16.3 | 14.5 | 13.6 |
| Swanbourne | 16.2 | 19.8 | 20.5 | 17.4 | 16.1 | 16.9 | 16.1 | 15.1 | 12.5 | 11.7 | 12.8 | 13.4 | 17.5 | 18.4 | 11.5 | 12.5 | 17.7 | 14.0 | 10.9 | 13.5 | 14.8 | 16.7 | 18.7 | 21.5 | 19.9 | 15.0 | 14.6 | 13.6 | 12.8 | 12.7 |
This table is very wide; you may have to scroll sideways to see all the days, and you may need to set the paper to 'landscape' to print.
| The temperatures in this table are coloured by 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 difference from average |
Details Extremes Records Summaries Important notes the top
| Daily rainfall | ||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Central Coast (09) | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 |
| Bickley | - | - | - | 15.4 | 2.2 | 10.2 | - | 17.4 | 10.6 | - | - | - | - | - | 0.6 | - | - | 6.6 | - | - | - | - | 0.2 | - | - | - | - | - | 1.4 | - |
| Champion Lakes | 18.6 | 0.2 | 3.2 | 8.4 | 11.8 | 3.2 | - | - | - | - | - | - | - | - | 3.8 | - | - | - | - | - | - | - | - | - | - | 2.0 | - | |||
| Garden Island HSF | - | - | - | 5.4 | - | 0.6 | 0.4 | 2.0 | 1.4 | - | - | - | - | - | 0.6 | - | - | 1.4 | - | - | - | - | - | - | - | - | - | - | 2.4 | - |
| Gosnells City | - | »» | 1.2 | 14.8 | 0.1 | 4.4 | 0.4 | 16.0 | 1.4 | - | - | - | - | - | - | - | - | 3.9 | - | - | - | - | - | - | - | - | - | - | 2.6 | - |
| Jandakot Aero | - | - | 2.2 | 11.8 | - | 4.4 | 3.0 | 4.2 | 1.2 | - | - | - | - | - | 0.4 | - | - | 3.8 | - | - | - | - | - | - | - | - | - | - | 0.6 | - |
| Jarrahdale | - | - | 0.4 | 11.0 | 0.4 | 6.8 | 3.2 | 14.0 | 8.4 | - | - | - | - | - | 0.4 | - | - | 1.2 | - | - | - | - | - | - | - | - | - | - | 1.8 | - |
| Medina Research Centre | - | - | 1.2 | 5.6 | 0.6 | 4.6 | 2.0 | 1.4 | 1.8 | - | - | - | - | - | - | - | - | 1.8 | - | - | - | - | - | - | - | - | - | - | 5.2 | - |
| Mundaring | 14.2 | 1.0 | 6.2 | 2.6 | 34.0 | 5.0 | 0.4 | 6.6 | 2.6 | |||||||||||||||||||||
| Pearce RAAF | - | 13.6 | 0.2 | 2.4 | 0.8 | 9.0 | 1.0 | - | - | - | - | - | - | - | 2.2 | - | - | - | - | - | - | - | - | - | - | |||||
| Perth Airport | - | - | 1.4 | 14.2 | 0.2 | 3.8 | 1.4 | 14.0 | 1.6 | - | - | - | - | - | - | - | - | 1.4 | - | - | - | - | - | - | - | - | - | - | 1.4 | - |
| Perth Metro | - | - | 2.2 | 7.2 | 0.2 | 3.2 | - | 13.2 | 0.6 | - | - | - | - | - | - | - | - | 2.2 | - | - | - | - | - | - | - | - | - | - | 0.2 | - |
| Roleystone | 6.2 | |||||||||||||||||||||||||||||
| Rottnest Island | - | - | 0.2 | 8.8 | 0.4 | 2.2 | - | 3.0 | 3.0 | - | - | - | - | - | - | - | - | 1.2 | - | 0.2 | - | - | - | - | - | - | - | - | 0.4 | - |
| Serpentine | - | - | 1.8 | 11.2 | 0.2 | 5.0 | 2.8 | 10.2 | 4.0 | - | - | - | - | - | 0.2 | - | - | 6.4 | - | - | - | - | - | - | - | - | - | - | 2.0 | - |
| Swanbourne | - | - | 2.6 | 6.8 | - | 3.8 | 0.4 | 15.4 | 2.4 | - | - | - | - | - | 0.2 | - | - | 3.0 | - | - | - | - | - | - | - | - | - | - | 0.6 | - |
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 marked like this 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).
This table is very wide; you may have to scroll sideways to see all the days, and you may need to set the paper to 'landscape' to print.
Details Extremes Records Summaries Important notes the top
Notes
A Monthly Climate Summary is prepared to list 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, usually published in the fourth week of the month.
This statement has been prepared based on information available at 3 pm on Wednesday 30 November 2011. Some checks have been made on the data, but it is possible that results will change as new information becomes available.
Averages 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.
Records in this summary are based on sites with at least 10 years of data.
*Official Perth observations have been recorded at several different sites with varying instrumentation over the years, and these changes can affect the continuity of the climate record. For the current Mt Lawley site, the most significant changes of this kind relate to minimum temperature and rain days.
For that reason, current mean temperature and rain-day data quoted here are based only on readings from the Mt Lawley site, which commenced observations in 1993. Sunshine recordings are from Perth Airport and for similar reasons current means use only Perth Airport data, which commenced in 1993.
For PDF files of Perth Metro climate statistics for other months, please click here for extremes and here for averages.
Further information
Western Australia Climate Services CentreBureau of Meteorology
Phone (08) 9263 2222
Email climate.wa@bom.gov.au
