Wednesday, 1 August 2012 - Monthly Climate Summary for South Australia - Product code IDCKGC13R0
South Australia in July 2012: Cold nights with below average rainfall for most of the State.
- Rainfall was below average across the State as a whole, with drier conditions across western districts tending to above average in parts of the east.
- Below average minimum temperatures across the State as a whole result in the coolest July nights in 15 years.
- Some sites observe a record lowest July daily minimum and a record lowest average July minimum temperature.
South Australia received about half of the July rainfall average for the State as a whole. Apart from areas across central and eastern districts where rainfall was average tending to above average, much of the rest of South Australia received below average rainfall. The wettest periods for much of the State occurred between the 10th and 14th and again between 26th and 28th. In the earlier period, a trough of low pressure caused thunderstorms in central and eastern districts, with heavy rain and hail affecting parts of the Barossa Valley and Adelaide Hills. Large amounts of hail up to 2cm in diameter were observed about the hills around Rowland Flat and Lyndoch. The heavy rain caused localised flash flooding in Mount Barker. The highest daily rainfall total for the month occurred at Birdwood (McVitties Hill) in the Mount Lofty Ranges, where 50.2 mm was recorded to 9 am on 13th. In the latter period, a trough of low pressure moved across southern and eastern parts of the State producing scattered showers resulting in falls generally between 20 to 30 mm to 9am on the 27th. Adelaide (Kent Town) recorded its wettest July day in 14 years with a total of 31.2mm to 9am on the 27th, while Greenacres reported 44.4mm and Belair (State Flora Nursery) in the Mount Lofty Ranges reported 42mm.
Rainfall for the year to the end of July 2012 is above average across the Northeast Pastoral district, but tending below average in the far west and in parts of the southeast. Elsewhere across the State rainfall has been average.
For the growing season rainfall so far (April to October), the April through to July rainfall totals have been near average across most of the agricultural districts apart from areas in the Upper North, the Northeast and the Upper and Lower Murray Valley where totals are below average.
Rainfall totals over the Pastoral districts were above average in the Northeast tending to average in the Far North and below average across the Northwest. A number of locations recorded no rainfall through July, not unusual for this time of the year for northern South Australia.
The wettest period for the Pastoral districts was between the 9th and 13th as a slow moving low pressure trough produced areas of rain and isolated thunderstorms. Most of the remainder of the month was without rain. Monthly totals generally ranged from 2 to 15 mm, in the Northwest and Far North with higher totals ranging between 20 to 30mm in the Northeast. The wettest overall was at Yunta (Paratoo) in the Northeast Pastoral district with 34.8 mm.
Western agricultural districts, parts of the Eyre and Yorke Peninsulas, Kangaroo Island, the Adelaide Plains and parts of the Lower Southeast saw mainly below average rainfall totals during July. The Murray Mallee, the Murray Valley and the Upper and Lower North districts generally received average to above average rainfall.
Totals were in the range of 40 to 60mm in most locations, but tending to higher totals up to about 100mm across the Mount Lofty and Flinders Ranges, the southeast of the State, and the Murray Malley and Riverland. The wettest overall for the month in the agricultural districts was Parawa (Second Valley Forest AWS) on the Fleurieu Peninsula, with 129.8 mm.Some sites had their lowest total July rainfall on record. Some sites had their lowest total July rainfall for at least 25 years. See a map of rainfall deciles.
The mean temperature (the average of the maximum and minimum temperatures) for South Australia as a whole in July 2012 was -0.64 °C below the long-term average, the coldest July for the State since 1998. Mean temperatures ranged from 7.2°C at Mount Lofty to 13.3°C at Neptune Island.
Mean maximum temperatures over South Australia were generally near normal, with several locations being within 0.5°C of average across the State. However, many locations in the Northwest, Western Agricultural, the Upper North, the Murray Valley and parts of the Upper Southeast observed below average daytime temperatures.
The coldest periods for many locations occurred through the first and last week of July owing to the presence of high pressure systems which maintained generally clear conditions across much of the State. A cold spell in the third week of July brought daytime temperatures to below average for several coastal and hills locations.
Mount Lofty recorded the coldest day of the month on the 14th when its maximum temperature only reached 6.5°C. The warmest period was early in the month and in the northerly air stream ahead of the cold front in the second week of the month when the warmest day recorded was at Marla Police Station, reaching 26.8°C on the 11th.
Average daily maximum temperatures ranged from 9.3°C at Mount Lofty to 19.6°C at Marree Comparison and Moomba Airport in the Northeast district.
See a map of maximum temperature anomalies.
Apart from the southeast corner of the State, mean minimum temperatures were widely below average across South Australia. When averaged across the State as a whole, July 2012 is coldest since 1997.
Large areas across the northwest of South Australia observed average July overnight minimum temperatures in excess of 2°C cooler than normal. Marla (Police Station) observed a record lowest average July night-time temperature of -0.1°C, which is 5.2°C below the long-term average for this location. Oodnadatta Airport also observed a record lowest average July daily minimum temperature of 2.8°C, where in 63 years of record the previous coolest July was 3.2°C in 1976.
The coldest nights occurred through the first week of July in clear skies and light winds owing to slow moving high pressure system positioned to the south of the State. The minimum temperature at Yunta fell to -7.5°C on the 6th during this period, the coldest night for any location during the month and the second coldest July daily minimum on record for this site since July 16, 1976 when the observed minimum was -7.9°C. Both Marla Police Station and Nullarbor observed record lowest daily minimum temperature; respectively observing -5.0°C and -2.2°C on the 7th.
The warmest nights for many locations occurred through the second week of July as a warm northwesterly airstream was directed across the State ahead of an approaching low pressure trough.
Moomba airport reported the warmest night for any location on the 12th with a minimum of 15.1°C
The warmest nights on average were observed at Neptune Island with 11.4°CSome sites had their lowest July temperature on record. Some sites had their lowest July mean daily minimum temperature on record. See a map of minimum temperature anomalies.
|Extremes in July 2012|
|Hottest day||26.8 °C at Marla Police Station on the 11th|
|Warmest days on average||
19.6 °C at Marree Comparison|
19.6 °C at Moomba Airport
|Coolest days on average||9.3 °C at Mount Lofty|
|Coldest day||6.5 °C at Mount Lofty on the 14th|
|Coldest night||-7.5 °C at Yunta Airstrip on the 6th|
|Coolest nights on average||-0.1 °C at Marla Police Station|
|Warmest nights on average||11.4 °C at Neptune Island|
|Warmest night||15.1 °C at Moomba Airport on the 12th|
|Warmest on average overall||13.3 °C at Neptune Island|
|Coolest on average overall||7.2 °C at Mount Lofty|
|Wettest overall||129.8 mm at Parawa (Second Valley Forest AWS)|
0 mm at Ernabella (Pukatja)|
0 mm at Marla Police Station
0 mm at Oodnadatta Airport
|Wettest day||50.2 mm at Birdwood (McVitties Hill) on the 13th|
|Highest wind gust||
102 km/h at Cape Borda on the 25th|
102 km/h at Neptune Island on the 25th
|Record lowest total July rainfall|
for July 2012 (mm)
|Oodnadatta Airport||0.0||= 0.0||in 2008||65||10.0|
|Moonaree (Kangaroo Well)||2.0||= 2.0||in 1999||27||21.3|
|Marla Police Station||0.0||= 0.0||in 2007||25||13.4|
|Lowest total July rainfall for at least 25 years|
for July 2012 (mm)
Most recent July
at least this dry
|Port Kenny||15.0||13.8||in 1976*||33||56.7|
|Port Vincent||16.8||13.7||in 1982*||29||46.5|
* note: there are gaps in the historical record at this site, so it is possible a lower value has gone unreported.
|Record lowest July temperature|
in July 2012 (°C)
|Marla Police Station||-5.0||on the 7th||-3.9||on the 20th in 1997||26||5.1|
|Nullarbor||-2.2||on the 7th||-2.0||on the 21st in 1997||26||5.2|
|Record lowest July mean daily minimum temperature|
Mean daily minimum
for July 2012 (°C)
|Oodnadatta Airport||2.8||3.2||in 1976||63||5.9|
|Marla Police Station||-0.1||2.8||in 2007||25||5.1|
|Summary statistics for July 2012|
|Northwest (district 16)|
|Coober Pedy Airport||17.7||23.0||11th||4.3||2.2||15th||0.2|
|Marla Police Station||18.4||-1.5||26.8||11th||-0.1||-5.2||-5.0||7th||0||13.4||lowest||0%|
|Roxby Downs (Olympic Dam Aerodrome)||18.2||22.0||8th||0.9||-3.0||6th||0.4|
|Far North (district 17)|
|Leigh Creek Airport||16.9||+0.3||21.8||8th||3.0||-1.8||-1.1||18th||1.4||17.4||v low||8%|
|Western Agricultural (district 18)|
|Cleve Aerodrome||14.9||18.9||17th||6.6||1.0||7th||19.2||43.9||v low||44%|
|Coulta (Coles Point)||15.1||-0.4||18.0||9th||6.9||-0.5||3.3||7th||61.8|
|North Shields (Port Lincoln AWS)||15.6||-0.5||17.8||17th||6.5||-1.1||2.8||7th||45.2|
|Port Augusta Aero||17.3||21.3||24th||3.6||-2.7||7th||27.2|
|Whyalla Aero||16.2||-0.7||20.5||24th||4.4||-0.8||-1.4||7th||43.4||23.7||v high||183%|
|Upper North (district 19)|
|Northeast (district 20)|
|Gluepot Reserve (Gluepot)||16.2||18.9||8th||2.7||-6.5||6th||25.4|
|Lower North (district 21)|
|Clare High School||12.4||16.3||24th||3.9||-1.9||3rd||89.6|
|Port Pirie Aerodrome||15.9||19.1||8th||5.5||1.1||3rd||63.6|
|Port Pirie Nyrstar Comparison||16.5||+0.1||20.0||8th||7.6||-0.1||3.8||6th||43.3||33.9||average||128%|
|Snowtown (Rayville Park)||14.9||18.3||8th||4.5||-0.9||7th||25.4|
|Yorke Peninsula (district 22A)|
|Kangaroo Island (district 22B)|
|Parndana Cfs AWS||13.9||16.9||20th||6.0||2.7||7th||59.4|
|Adelaide Plains (district 23A)|
|Adelaide (Kent Town)||15.3||0.0||19.0||24th||7.8||+0.3||2.3||6th||64.8||75.0||average||86%|
|County Light (district 23B)|
|Rosedale (Turretfield Research Centre)||14.7||0.0||18.4||24th||5.7||+0.2||0.0||6th||55.9||58.9||average||95%|
|Mount Lofty Ranges (district 23C)|
|Hindmarsh Island AWS||15.1||18.4||24th||8.0||2.0||6th||63.6|
|Kuitpo Forest Reserve||12.1||16.6||12th||6.5||2.6||7th||94.2|
|Mount Crawford (Mt Crawford AWS)||11.0||14.8||12th||5.7||2.8||1st||51.2|
|Parawa (Second Valley Forest AWS)||11.9||14.4||24th||6.9||2.5||7th||129.8|
|Victor Harbor (Encounter Bay)||15.2||17.6||24th||6.2||-0.7||7th||118.8|
|Upper Murray Valley (district 24A)|
|Loxton Research Centre||15.7||-0.1||18.4||17th||4.1||+0.3||-3.5||6th||27.8||28.3||average||98%|
|Lower Murray Valley (district 24B)|
|Murray Bridge (Pallamana Aerodrome)||14.9||18.1||24th||4.6||-3.8||7th||56.4|
|Murray Bridge Comparison||15.6||-0.6||19.2||24th||5.3||-0.1||-1.5||7th||63.5||35.4||v high||179%|
|Murray Mallee (district 25A)|
|Upper Southeast (district 25B)|
|Lameroo (Austin Plains)||14.3||17.0||17th||4.5||-0.7||7th||34.4|
|Lower Southeast (district 26)|
|Cape Jaffa (The Limestone)||14.2||+0.2||16.6||21st||7.6||+0.1||1.4||7th||79.6|
|Mount Gambier Aero||14.1||+0.9||16.2||21st||5.6||+0.4||-0.3||6th||73.6||98.9||low||74%|
A Monthly Climate Summary is prepared to list the main features of the weather in South Australia 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 Wednesday 1 August 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 20 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
(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.