Wednesday, 31 October 2012 - Monthly Climate Summary for Adelaide Metro & Hills - Product code IDCKGC26L0
Adelaide Metro & Hills in October 2012: Dry and warm conditions persist across the Adelaide region
- Rainfall was very much below average across the Adelaide region with many locations receiving less than half of the long term October average.
- Adelaide observed its driest October in 3 years.
- Despite very cold temperatures in the second week of October which resulted in a rare snow event, daytime temperatures were in excess of 1°C above average while night time temperatures were near average.
- Adelaide's warmest October days in 4 years.
The October 2012 rainfall total at Adelaide (Kent Town) was 20.0mm received on 5 rain days. This is less that half of the long term average of 43.8 mm received on 10 or more rain days, and results in the driest October in the Adelaide region since 2009 when only 18.4 mm was observed. The long term median October rainfall for Adelaide (Kent Town) is 37.0 mm, last time exceeded in October 2011 when 42.6 mm was observed. The driest October at Adelaide (Kent Town) was observed in 2006 when just 1.0mm was recorded.
Most of the rainfall during October for the Adelaide and Hills region, was observed in just one day. On the 10th, a strong cold frontal system and associated cold air mass moved over South Australia which resulted in heavy showers, snow fall and hail in several locations about the Adelaide and Mt Lofty Ranges. Adelaide (Kent Town) recorded 16.4 mm to 9am on the 11th as a result of this event; Kuitpo Forest Reserve was the wettest overall this day with 29 mm.
Most locations received less than half of the long term October average with monthly rainfall totals typically ranging between 10 to 20mm on the Adelaide Plains, with higher totals in the 30 to 40mm range throughout the Adelaide Hills. The wettest location across the region was at Kuitpo Forest Reserve where 40.0 mm was recorded for the month.
Note that the Adelaide official climate rainfall record is taken from the manually observed 203mm rain gauge at the Kent Town site in Adelaide. These figures may differ from totals on some Bureau of Meteorology web pages as these may be from automatic tipping bucket rain gauge readings.
The average maximum temperature recorded at Adelaide (Kent Town) for October 2012 was 23.1°C, 1.3°C above the long term average October maximum temperature resulting in the warmest October since 2008 when the average maximum temperatures were 24.1°C. By comparison, October 2011 saw average maximum temperatures of 22.1°C at Adelaide (Kent Town). The record warmest October average maximum in Adelaide is 26.8°C, observed in 1914 at the West Terrace site.
Several warm periods contributed to the warmer than average October, as high pressure systems, clear skies and above average sunshine hours dominated the weather throughout the month. The hottest day for any location across the Adelaide and Hills region was reported at Edinburgh RAAF where the maximum reached 34.3°C on the 30th. Parafield Airport reported the warmest days on average, with a monthly average of 23.7 °C, which is 2.0 °C above the long term average for this site.
Daytime temperatures in the Adelaide region were coolest on the 10th and 11th owing to a pool of cold air associated with the strong cold frontal system, resulting in very much below average temperatures with snow across parts of the Adelaide Hills. The coldest day of the month for any location in the Adelaide and Hills region was reported at Mount Lofty on the 11th when the maximum reached 7.8 °C. The coolest days on average were at Mount Lofty where the October maximum temperature averaged 17.5 °C.
Mean minimum temperatures were generally below average across the Adelaide Plains and Hills this October. The minimum temperature at Adelaide (Kent Town) averaged 10.7°C, 0.8 °C below the long term October average. During October 2011, the minimum temperatures averaged 13.0 °C. Reduced cloud cover can be attributed to the below average temperatures this October.
The coldest nights for most locations occurred through the second week of October as a high pressure system centred well south of South Australia directed a very cold airmass over the State.
The coldest minimum temperature during October 2012 in the Adelaide and Hills area was 0.4 °C observed at Mount Lofty on the 11th and again on the 12th. The coolest nights on average were recorded at Mount Lofty with 7.7 °C. Mount Barker observed an average October minimum of 8.1°C, 0.7°C above the long term October average for that site. The warmest night was observed at Kuitpo Forest Reserved and Noarlunga with 21.0°C on the 31st. Noarlunga also recorded the warmest nights overall, with a monthly average of 11.0 °C
|Extremes in October 2012|
|Hottest day||34.3 °C at Edinburgh RAAF on the 30th|
|Warmest days on average||23.7 °C at Parafield Airport|
|Coolest days on average||17.5 °C at Mount Lofty|
|Coldest day||7.8 °C at Mount Lofty on the 11th|
0.4 °C at Mount Lofty on the 11th|
0.4 °C at Mount Lofty on the 12th
|Coolest nights on average||7.7 °C at Mount Lofty|
|Warmest nights on average||11.0 °C at Noarlunga|
21.0 °C at Kuitpo Forest Reserve on the 31st|
21.0 °C at Noarlunga on the 31st
|Warmest on average overall||16.8 °C at Adelaide (Kent Town)|
|Coolest on average overall||12.4 °C at Mount Lofty|
|Wettest overall||40.0 mm at Kuitpo Forest Reserve|
|Driest overall||5.6 mm at Mount Crawford (Mt Crawford AWS)|
|Wettest day||29.0 mm at Kuitpo Forest Reserve on the 11th|
|Highest wind gust||83 km/h at Edinburgh RAAF on the 11th|
|Summary statistics for October 2012|
|Adelaide (Kent Town)||23.1||+1.3||33.9||30th||10.7||-0.8||4.9||11th||20.0||43.8||low||46%|
|Kuitpo Forest Reserve||19.3||29.9||30th||9.1||2.7||11th||40.0|
|Mount Crawford (Mt Crawford AWS)||19.5||30.5||30th||8.4||1.1||11th||5.6|
A Monthly Climate Summary is prepared to list the main features of the weather in Adelaide Metro & Hills 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 2 pm on Wednesday 31 October 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.