Wednesday, 1 August 2012 - Monthly Climate Summary for Perth - Product code IDCKGC11L0
Perth in July 2012: Driest July on record
- Rainfall: driest July on record for most sites
- Maximum temperature: above average for most sites, with record highs at some sites
- Minimum temperature: very much below average for most sites, with record lows at some sites
Details Extremes Records Summaries Important notes the top
Rainfall
Due to persistent high pressure systems over southern WA and a contraction of cold fronts and westerly flow southwards during the month, July rainfall totals across the Perth metropolitan area were lowest on record at almost all sites (see the records tables). Rainfall totals in the region were in the 20 to 50 mm range, more than 100 mm less than the long-term average at most sites, and significantly below the previous July record. This event was particularly notable given that some sites have over 100 years of record (Perth Metro 136 years, Jarrahdale 128 years, and Mundaring 111 years), and the low monthly rainfall easily exceeded their previous lowest July total.
July 2012 saw only a handful of light rainfall events in the Perth area, with daily rainfall totals generally less than 10 mm. A slow moving cold front and pre-frontal trough brought generally light rainfall to the Perth area on the 6th and 7th, followed by further mainly light rainfall from a low and associated middle level disturbance on the 10th. A westerly flow and the passage of weak cold fronts brought light rainfall on the 16th, while a weak front brushed southwest WA with the Perth area only recording light rainfall on the 23rd, with a daily falls less than 5 mm for most of sites. A cold front and pre-frontal trough moved over southwest WA during the early morning of the 31st, bringing welcome moderate rainfall to the metropolitan area, though totals in the 24 hours to 9am on the 31st were below 13 mm.
Perth Metro recorded 34.6 mm of rainfall on 8 rain days in July 2012, easily breaking the previous lowest July total of 61.5 mm on 9 rain days in 1876. As a result of the extraordinarily dry July, and a near average June, Perth Metro recorded its 3rd driest June to July period with 175.4 mm on 26 rain days. It was also the 4th driest January to July period on record at Perth Metro with 336.2 mm on 51 rain days, mainly due to a below average May and the record low July.
Maximum temperature
Mean maximum temperatures in July 2012 were above average for most sites in the Perth metropolitan area and mostly between 18 °C and 20 °C. Swanbourne on the coast recorded their warmest July in 18 years of record, whilst Bickley in the hills saw its equal warmest July in 18 years of record, equal with 1999. Medina in the southern suburbs also experienced its equal warmest July in 25 years of record, equal with 2007.
Warm conditions were observed across Perth in the first week of July 2012 due to a strong high to the south of the state directing warm northerly winds over the region. Maximum temperatures were regularly above 20 °C for the first six days at most sites and Perth Metro recorded its warmest start to July since records began in 1897 with a mean maximum of 21.6 °C in the first seven days. Maximum temperatures dropped to below normal between the 8th and 12th, and again on the 17th and 18th as cold fronts and a westerly flow affected the region. Warm weather returned between the 20th and 23rd due to a strong high pressure cell in the Bight, before a westerly flow resulted in a dip in temperatures on the 24th and 25th, with a number of sites registering their coldest day of the month on the 24th. Warm conditions returned towards the end of the month as a high re-established itself in the Bight, with most sites observing their warmest day for July 2012 on the 30th. The daily maximum temperature of 24.4 °C at Swanbourne on the 30th was the highest temperature of the month in the Perth metropolitan area.
Perth Metro's mean daily maximum temperature in July was 19.4 °C, which was its warmest July for five years since a mean of 19.5 °C was recorded in 2007. Daily maxima ranged from a cold 14.8 °C on the 24th to a warm 23.8 °C on the 30th, whilst the average maximum for July at Perth Metro is 18.3 °C.
Minimum temperature
Mean minimum temperatures in July 2012 were below to very much below average for most sites in the Perth metropolitan area, with mean minima mostly in the 5 °C to 8 °C range and 2 to 3 °C cooler than normal, with only Rottnest Island above 10 °C. Perth Metro, Medina Research Centre, Jandakot Aerodrome, and Garden Island all registered their lowest mean minimum temperature for July on record.
Cool to cold nights were observed for most of July 2012, with generally clear skies throughout much of the month. The coldest night at most sites occurred on the 25th when Perth Airport, Pearce RAAF, and Jandakot Aerodrome registered sub-zero overnight temperatures. Jandakot Aerodrome also observed sub-zero temperatures on the 5th and 26th. Only a handful of nights scattered throughout July 2012 saw overnight temperatures above normal, generally coincident with cloudy conditions before a cold front moved through the metropolitan area.
Perth Metro's mean daily minimum temperature in July was 5.2 °C, which is the lowest mean minimum for any month at the current Mt Lawley site since records commenced in November 1993. Perth Metro recorded a total of 19 cold nights (a cold night at Perth Metro is a minimum of less than 5 °C), which is the greatest number recorded for any month at Perth Metro. The previous record was 16 cold nights in July 1998, 2001, and 2010. Perth Metro minima ranged from a cold 0.4 °C on the 25th to a mild 12.4 °C on the 22nd.
Sunshine
Perth recorded an average daily sunshine of 7.4 hours in July 2012, which was the second sunniest July on record, behind the 7.5 hours in July 1918. The average sunshine for July is 6.0 hours per day.
Further information
Western Australia Climate Services CentreBureau of Meteorology
Phone (08) 9263 2222
Email climatedata@bom.gov.au
| Extremes in July 2012 | |
|---|---|
| Hottest day | 24.4 °C at Swanbourne on the 30th |
| Warmest days on average | 19.5 °C at Gosnells City |
| Coolest days on average | 15.9 °C at Bickley |
| Coldest day | 11.9 °C at Bickley on the 9th |
| Coldest night | -1.6 °C at Jandakot Aero on the 25th |
| Coolest nights on average | 3.8 °C at Jandakot Aero |
| Warmest nights on average | 12.2 °C at Rottnest
Island 7.8 °C at Swanbourne |
| Warmest night | 15.8 °C at Rottnest
Island on the 6th 14.8 °C at Pearce RAAF on the 22nd |
| Wettest overall | 54.8 mm at Rottnest Island 47.8 mm at Jarrahdale |
| Wettest day | 12.6 mm at Rottnest Island
on the 17th 12.4 mm at Roleystone on the 31st |
| Highest wind gust | 78 km/h at Rottnest Island on the 23rd |
Extremes Records Summaries Important notes the top
| Record lowest total July rainfall | |||||
|---|---|---|---|---|---|
| Total rainfall for July 2012 (mm) |
Previous driest for July |
Years of record |
Average for July |
||
| Perth Metro* | 34.6 | 61.5 | in1876 | 136 | 165.4 |
| Jarrahdale | 47.8 | 72.7 | in 1959 | 128 | 227.1 |
| Mundaring | 43.8 | 58.7 | in 1889 | 111 | 214.5 |
| Perth Airport | 30.6 | 63.4 | in 2005 | 69 | 157.3 |
| Pearce RAAF | 23.2 | 54.4 | in 1976 | 58 | 135.2 |
| Gosnells City | 35.6 | 70.3 | in 2005 | 51 | 161.6 |
| Bickley | 31.6 | 97.4 | in 1976 | 44 | 217.5 |
| Jandakot Aero | 34.6 | 76.4 | in 1976 | 38 | 174.5 |
| Medina Research Centre | 28.9 | 76.1 | in 2005 | 30 | 147.6 |
| Swanbourne | 42.0 | 54.8 | in 2005 | 19 | 145.8 |
| Garden Island HSF | 40.6 | 55.2 | in 2005 | 11 | 114.4 |
| Record highest July mean daily maximum temperature | |||||
|---|---|---|---|---|---|
|
Mean daily maximum temperature for July 2012 (°C) |
Previous warmest for July |
Years of record |
Average for July |
||
| Medina Research Centre | 19.4 | = 19.4 | in 2007 | 25 | 18.2 |
| Bickley | 15.9 | = 15.9 | in 1999 | 18 | 15.0 |
| Swanbourne | 19.5 | 19.4 | in 2007 | 18 | 18.3 |
| Record lowest July mean daily minimum temperature | |||||
|---|---|---|---|---|---|
| Mean daily minimum temperature for July 2012 (°C) |
Previous coolest for July |
Years of record |
Average for July |
||
| Medina Research Centre | 5.4 | 6.0 | in 2001 | 25 | 8.3 |
| Jandakot Aero | 3.8 | 4.1 | in 2001 | 22 | 6.8 |
| Perth Metro* | 5.2 | 5.3 | in 1997 | 19 | 7.9 |
| Garden Island HSF | 9.9 | 10.1 | in 2010 | 10 | 11.1 |
Extremes Records Summaries Important notes the top
| Summary statistics for July 2012 | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Maximum temperatures for July (°C) |
Minimum temperatures for July (°C) |
Rainfall for July (millimetres) |
||||||||||
| Mean for July 2012 |
Diff from average |
Highest for July 2012 |
Mean for July 2012 |
Diff from average |
Lowest for July 2012 |
Total for July 2012 |
Average for July |
Rank of July 2012 |
Fraction of July average |
|||
| Bickley | 15.9 | +0.9 | 20.2 | 21st | 6.3 | -0.8 | 2.9 | 9th | 31.6 | 217.5 | lowest | 15% |
| Champion Lakes | 18.5 | 22.9 | 21st | 7.6 | 2.7 | 25th | 30.2 | |||||
| Garden Island HSF | 17.8 | 0.0 | 22.3 | 30th | 9.9 | -1.2 | 5.6 | 13th | 40.6 | 114.4 | lowest | 35% |
| Gosnells City | 19.5 | +0.9 | 24.2 | 30th | 35.6 | 161.6 | lowest | 22% | ||||
| Jandakot Aero | 18.9 | +1.1 | 23.7 | 30th | 3.8 | -3.0 | -1.6 | 25th | 34.6 | 174.5 | lowest | 20% |
| Medina Research Centre | 19.4 | +1.2 | 24.0 | 21st | 5.4 | -2.9 | 0.3 | 25th | 28.9 | 147.6 | lowest | 20% |
| Pearce RAAF | 18.8 | +1.0 | 23.1 | 30th | 5.6 | -2.9 | -0.8 | 25th | 23.2 | 135.2 | lowest | 17% |
| Perth Airport | 19.2 | +1.3 | 23.8 | 21st | 5.6 | -2.4 | -0.7 | 25th | 30.6 | 157.3 | lowest | 19% |
| Perth Metro | 19.4 | +1.1 | 23.8 | 30th | 5.2 | -2.5 | 0.4 | 25th | 34.6 | 165.4 | lowest | 21% |
| Rottnest Island | 18.1 | +0.4 | 22.1 | 30th | 12.2 | -0.1 | 9.1 | 18th | 54.8 | 143.9 | v low | 38% |
| Swanbourne | 19.5 | +1.2 | 24.4 | 30th | 7.8 | -1.9 | 3.9 | 25th | 42.0 | 145.8 | lowest | 29% |
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 | 31 |
| Bickley | 17.8 | 17.6 | 17.1 | 18.1 | 19.2 | 19.0 | 16.7 | 12.9 | 11.9 | 13.3 | 13.8 | 12.9 | 14.8 | 15.5 | 16.1 | 13.6 | 13.2 | 13.7 | 15.5 | 18.4 | 20.2 | 19.5 | 17.0 | 12.0 | 13.0 | 15.9 | 16.2 | 17.1 | 17.0 | 19.8 | 14.6 |
| Champion Lakes | 20.8 | 20.9 | 19.5 | 20.7 | 21.7 | 20.5 | 18.9 | 15.2 | 14.2 | 15.7 | 16.5 | 14.3 | 16.7 | 17.6 | 19.1 | 16.6 | 15.7 | 16.1 | 18.5 | 22.2 | 22.9 | 22.6 | 19.8 | 14.0 | 14.7 | 18.5 | 19.6 | 19.8 | 19.6 | 22.2 | 18.3 |
| Garden Island HSF | 19.2 | 20.0 | 19.5 | 20.8 | 21.3 | 21.3 | 16.9 | 15.5 | 15.4 | 15.9 | 15.7 | 14.5 | 16.1 | 17.4 | 19.4 | 16.8 | 14.9 | 14.0 | 16.7 | 19.0 | 18.1 | 20.7 | 18.8 | 13.8 | 14.9 | 16.4 | 16.7 | 20.3 | 19.6 | 22.3 | 20.2 |
| Gosnells City | 21.6 | 21.8 | 21.4 | 22.7 | 23.0 | 20.5 | 15.8 | 14.9 | 17.7 | 17.3 | 15.7 | 17.5 | 19.0 | 20.2 | 17.4 | 16.8 | 17.4 | 19.4 | 22.3 | 24.2 | 23.9 | 20.9 | 15.0 | 15.5 | 19.1 | 19.5 | 21.5 | 21.2 | 24.2 | 18.8 | |
| Jandakot Aero | 20.6 | 20.7 | 20.2 | 21.5 | 22.8 | 21.5 | 19.2 | 15.7 | 14.8 | 16.7 | 17.1 | 15.0 | 17.6 | 18.3 | 19.9 | 17.3 | 15.9 | 16.0 | 21.4 | 23.5 | 22.0 | 20.2 | 14.6 | 15.1 | 18.7 | 18.5 | 20.5 | 20.2 | 23.7 | 18.9 | |
| Medina Research Centre | 21.1 | 21.6 | 20.6 | 22.3 | 23.2 | 22.7 | 19.1 | 16.0 | 15.4 | 17.5 | 17.0 | 15.1 | 17.5 | 19.5 | 20.5 | 18.0 | 16.4 | 16.4 | 18.5 | 21.5 | 24.0 | 22.7 | 21.4 | 14.7 | 15.3 | 19.0 | 19.5 | 21.0 | 20.4 | 23.8 | 19.1 |
| Pearce RAAF | 20.2 | 19.6 | 20.0 | 20.9 | 21.8 | 21.9 | 19.0 | 15.2 | 14.7 | 15.6 | 16.7 | 17.6 | 18.2 | 19.1 | 16.7 | 16.3 | 16.0 | 18.0 | 21.9 | 22.2 | 21.9 | 19.8 | 15.1 | 15.8 | 18.4 | 18.6 | 19.4 | 20.5 | 23.1 | 20.2 | |
| Perth Airport | 21.0 | 21.0 | 20.1 | 21.6 | 22.9 | 22.5 | 20.1 | 15.8 | 14.7 | 16.3 | 17.4 | 16.0 | 17.9 | 18.3 | 19.4 | 16.5 | 16.6 | 16.9 | 18.6 | 21.3 | 23.8 | 22.9 | 20.1 | 15.4 | 16.1 | 19.2 | 19.3 | 20.2 | 20.2 | 23.3 | 18.6 |
| Perth Metro | 21.6 | 21.0 | 20.5 | 22.2 | 22.8 | 22.6 | 20.3 | 16.0 | 15.0 | 15.7 | 17.3 | 15.7 | 17.7 | 18.8 | 20.2 | 17.3 | 16.6 | 16.5 | 18.7 | 21.8 | 23.6 | 23.4 | 20.5 | 14.8 | 15.9 | 19.3 | 19.3 | 20.7 | 20.8 | 23.8 | 19.5 |
| Rottnest Island | 19.9 | 20.3 | 20.3 | 21.0 | 21.4 | 20.7 | 17.8 | 14.5 | 14.4 | 15.2 | 15.7 | 14.6 | 16.8 | 17.8 | 19.9 | 16.7 | 14.9 | 14.6 | 17.4 | 19.8 | 20.1 | 21.3 | 20.1 | 13.1 | 15.8 | 17.5 | 17.7 | 19.5 | 19.4 | 22.1 | 19.6 |
| Swanbourne | 20.5 | 21.4 | 21.0 | 22.6 | 22.6 | 22.4 | 19.0 | 16.4 | 15.0 | 17.4 | 17.9 | 16.0 | 17.8 | 18.6 | 20.5 | 18.8 | 17.3 | 16.7 | 18.5 | 21.7 | 24.1 | 22.7 | 20.0 | 15.8 | 16.0 | 18.6 | 18.6 | 21.6 | 21.1 | 24.4 | 19.5 |
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 |
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 | 31 |
| Bickley | 7.4 | 7.1 | 5.6 | 4.2 | 5.3 | 9.8 | 11.4 | 5.6 | 2.9 | 5.5 | 6.3 | 4.2 | 6.8 | 5.7 | 8.5 | 9.9 | 6.1 | 3.3 | 3.2 | 5.3 | 5.4 | 9.8 | 10.0 | 3.3 | 3.7 | 5.6 | 4.4 | 4.6 | 5.2 | 7.6 | 11.5 |
| Champion Lakes | 7.6 | 8.3 | 8.3 | 8.0 | 8.3 | 7.8 | 11.6 | 7.9 | 6.2 | 8.4 | 6.2 | 5.7 | 5.0 | 5.3 | 8.2 | 12.0 | 6.4 | 7.1 | 4.0 | 6.0 | 9.2 | 11.8 | 8.0 | 4.7 | 2.7 | 4.4 | 7.0 | 7.6 | 7.9 | 12.6 | 12.2 |
| Garden Island HSF | 9.9 | 9.8 | 10.2 | 11.5 | 11.1 | 13.1 | 12.3 | 9.8 | 7.4 | 9.4 | 11.0 | 8.7 | 5.6 | 8.6 | 12.1 | 15.1 | 11.2 | 6.9 | 6.2 | 7.1 | 8.9 | 13.2 | 9.6 | 8.3 | 7.5 | 6.3 | 8.4 | 9.0 | 10.7 | 12.6 | 14.8 |
| Gosnells City | 5.0 | 6.5 | 8.2 | 7.5 | 7.1 | 11.0 | 7.5 | 4.4 | 3.5 | 6.8 | 8.0 | 7.6 | 4.5 | 1.6 | 3.5 | 5.0 | 7.0 | 8.0 | 10.1 | 12.3 | |||||||||||
| Jandakot Aero | 3.5 | 2.6 | 2.8 | 0.6 | -0.2 | 2.7 | 9.4 | 6.1 | 3.6 | 9.1 | 4.1 | 0.5 | 1.3 | 0.9 | 7.6 | 9.6 | 5.5 | 1.5 | 0.2 | 0.0 | 3.5 | 11.1 | 4.9 | 0.8 | -1.6 | -0.4 | 1.1 | 2.3 | 2.8 | 10.4 | 12.2 |
| Medina Research Centre | 5.0 | 5.5 | 3.9 | 7.2 | 6.5 | 6.9 | 10.9 | 6.3 | 2.0 | 8.8 | 6.4 | 2.3 | 2.5 | 2.2 | 8.0 | 10.0 | 7.4 | 3.0 | 1.7 | 2.4 | 3.5 | 11.3 | 6.0 | 2.6 | 0.3 | 1.0 | 2.4 | 5.4 | 5.7 | 8.9 | 12.8 |
| Pearce RAAF | 5.1 | 5.2 | 5.8 | 5.0 | 6.3 | 2.6 | 9.1 | 7.1 | 4.4 | 9.2 | 7.4 | 3.6 | 2.3 | 0.8 | 9.2 | 9.4 | 3.7 | 4.1 | 0.9 | 4.0 | 5.9 | 14.8 | 9.7 | 3.1 | -0.8 | 0.0 | 2.2 | 3.1 | 6.4 | 11.7 | 12.5 |
| Perth Airport | 4.3 | 5.4 | 8.2 | 7.8 | 7.5 | 5.0 | 10.3 | 6.8 | 3.3 | 7.7 | 7.4 | 2.8 | 2.7 | 2.5 | 8.6 | 9.6 | 3.9 | 3.2 | 0.5 | 3.0 | 4.7 | 12.1 | 6.1 | 4.4 | -0.7 | 0.5 | 4.7 | 3.3 | 7.0 | 10.2 | 11.5 |
| Perth Metro | 4.7 | 4.3 | 3.2 | 2.5 | 2.6 | 4.9 | 10.9 | 7.8 | 4.3 | 8.2 | 7.0 | 3.7 | 3.2 | 3.1 | 8.8 | 10.8 | 5.0 | 2.2 | 1.2 | 1.8 | 4.3 | 12.4 | 6.9 | 5.0 | 0.4 | 1.6 | 2.5 | 3.1 | 3.7 | 7.7 | 12.2 |
| Rottnest Island | 13.6 | 12.9 | 13.6 | 13.4 | 14.7 | 15.8 | 15.3 | 10.8 | 9.3 | 10.3 | 11.5 | 10.6 | 11.8 | 10.8 | 13.4 | 14.7 | 11.0 | 9.1 | 10.6 | 12.2 | 11.9 | 14.2 | 14.8 | 9.3 | 9.2 | 10.4 | 11.5 | 11.0 | 12.5 | 13.1 | 15.5 |
| Swanbourne | 7.6 | 7.9 | 7.8 | 8.0 | 8.1 | 9.2 | 12.3 | 7.6 | 4.7 | 8.6 | 7.4 | 5.4 | 6.4 | 6.6 | 9.5 | 13.7 | 8.4 | 4.9 | 4.5 | 6.2 | 7.2 | 12.9 | 9.5 | 5.4 | 3.9 | 5.9 | 5.6 | 6.1 | 7.0 | 11.4 | 12.9 |
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 |
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 | 31 |
| Bickley | 0.2 | - | - | - | - | - | 4.4 | 0.4 | - | 5.6 | 1.4 | - | 0.2 | 0.2 | - | 2.0 | 5.8 | 0.2 | - | - | - | - | - | 1.0 | - | 0.2 | - | - | - | - | 10.0 |
| Champion Lakes | 0.2 | - | - | - | - | - | 5.2 | 0.4 | - | 5.2 | 1.2 | - | - | - | 0.8 | 1.2 | 5.4 | - | 0.2 | - | - | - | - | 0.8 | - | - | - | - | - | - | 9.6 |
| Garden Island HSF | 0.2 | 0.2 | - | - | - | - | 4.2 | 0.6 | - | 6.4 | 8.0 | - | - | - | 0.6 | 3.4 | 2.0 | - | - | - | 0.2 | - | - | 1.8 | - | 0.4 | - | - | - | - | 12.6 |
| Gosnells City | - | - | - | - | - | »» | 5.2 | 0.4 | - | 5.8 | 2.1 | - | - | - | - | 2.1 | 5.2 | 0.1 | - | - | - | - | - | 6.0 | 1.0 | - | - | - | - | - | 7.7 |
| Jandakot Aero | - | - | - | - | - | - | 7.8 | 0.6 | - | 6.0 | 2.2 | - | 0.2 | - | - | 1.4 | 8.4 | - | - | - | - | - | 1.2 | - | - | - | - | - | - | 6.8 | |
| Jarrahdale | 0.2 | - | 0.2 | 0.4 | 0.2 | - | 7.8 | 1.0 | - | 5.0 | 5.8 | 0.4 | 0.2 | 0.2 | 0.8 | 4.4 | 4.6 | - | 0.4 | 0.2 | 0.2 | - | - | 7.2 | 0.2 | 0.2 | 0.2 | 0.2 | - | - | 7.8 |
| Medina Research Centre | - | - | - | - | - | - | 3.4 | 0.7 | - | 5.6 | 8.0 | - | - | - | 0.2 | 7.6 | 1.8 | - | - | - | - | - | - | 1.6 | - | - | - | - | - | - | 10.5 |
| Mundaring | 0.2 | 0.2 | 7.4 | 1.2 | 8.4 | 5.0 | 0.2 | 0.2 | 0.2 | 4.0 | 8.4 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 0.2 | 2.0 | 0.2 | 0.2 | 0.2 | 0.2 | 4.4 | ||||||||
| Pearce RAAF | - | - | - | - | - | 4.2 | 0.8 | - | 5.2 | 4.8 | - | - | 3.0 | 3.6 | - | 1.4 | - | 0.2 | - | - | - | - | - | - | |||||||
| Perth Airport | - | - | - | - | - | - | 7.0 | - | - | 6.6 | 3.8 | - | - | - | - | 0.6 | 6.8 | - | 0.2 | - | - | - | - | - | 0.2 | - | - | - | - | - | 5.4 |
| Perth Metro | - | - | - | - | - | - | 9.0 | 0.2 | - | 6.4 | 3.2 | - | - | - | - | 3.6 | 5.0 | - | - | - | - | - | - | 0.4 | - | - | - | - | - | - | 6.8 |
| Roleystone | 5.6 | 2.4 | 12.4 | ||||||||||||||||||||||||||||
| Rottnest Island | - | - | - | - | - | - | 6.0 | 3.0 | - | 5.2 | 10.8 | - | - | - | 0.2 | 0.4 | 12.6 | - | - | - | - | - | 0.4 | 6.4 | - | - | - | - | - | - | 9.8 |
| Serpentine | - | - | - | - | - | - | 8.8 | 0.6 | 0.2 | 5.6 | 8.4 | - | - | - | 0.6 | 2.4 | 3.6 | - | - | - | - | - | - | 4.4 | - | - | - | - | - | - | 10.4 |
| Swanbourne | - | - | - | - | - | - | 12.0 | 0.4 | - | 6.8 | 3.2 | - | 0.2 | 0.2 | 0.2 | 1.0 | 5.0 | - | - | - | - | - | 0.4 | 1.6 | - | 0.2 | 0.2 | - | - | - | 10.6 |
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.
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 10 am on Tuesday 31 July 2012. 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.
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 climatedata@bom.gov.au
