Wednesday, 2 January 2013 - Annual Climate Summary for Canberra - Product code IDCKGC35R0
Canberra Airport recorded 695.8 mm of rain during 2012, above the historical average of 614 mm and the wettest year since 2010. The rain fell over 96 days, below the average of 106 days and the fewest since 2009, with four days exceeding 25 mm and two exceeding 50 mm. Throughout the ACT, the highest annual total was 1280.8 mm at Mt Ginini (average 1034.9 mm), while Tharwa reached 864.4 mm.
Rainfall was generally above average at the start of the year associated with the 2011–12 La Niña event, with the two-month total of February–March the fifth-wettest two-month period for any month since records began in 1939. The most significant rainfall event of the year occurred associated with a slow-moving low pressure trough during this period, which resulted in flooding across southern NSW including parts of the ACT. Canberra Airport recorded 179.6 mm of rain between 29 February and 4 March, with rainfall exceeding 50 mm on the 1st and 4th.
Rainfall was generally close to normal for the remainder of the year following the breakdown of the La Niña event, with 325.4 mm recorded between April and December (average 450 mm), the driest end to a year since 2006 (227.6 mm). Only one day exceeded 25 mm during this period, when an East Coast Low off the NSW south coast produced 48-hour totals of 56.6 mm to 9am on 12 October.
The average maximum temperature at Canberra Airport during 2012 was 20.1 °C, 0.4 °C above the historical average. Temperatures were very cool at the start of the year associated with the cloudy and wet conditions, with the coldest January–March for Canberra since 1996. Temperatures gradually warmed throughout the year, with days 0.9 °C above average during winter and 2 °C above average during spring.
Only 26 days reached at least 30 °C (average 32 days), and only seven dropped below 10 °C (average 19 days); winter was the first on record to observe no days below 9 °C since records began in 1939. The coldest day was 8.6 °C on 11 October, which was the coldest October day since 1968 and resulted in reports of snow in the ACT; in nearby Goulburn this was the first report of spring snow since 22 November 1996.
The average minimum temperature for Canberra Airport was 5.6 °C, 0.9 °C below the historical average. This is the equal-fifth-coolest year on record for Canberra, and the coldest year for minimum temperatures since 1972. Nights were cooler than normal for every month between December 2011 and October 2012, the longest cold spell for Canberra since the twelve months ending November 1970.
There were 88 nights with minimums of 0 °C or lower (average 60 nights), the equal-second-highest number of cold nights on record for Canberra. The coldest night in Canberra was –6.8 °C on 1 September, which was the coldest September night on record; three consecutive nights fell below –4 °C on 1–3 September. This was the latest such cold spell on record, with the previous record almost two weeks earlier in the year - 22–24 August 1978.
The mean temperature at Canberra Airport was consequently 0.3 °C below the historical average, the coldest year since 1996.Some sites had their lowest temperature on record.
|Extremes in 2012|
|Hottest day||35.1 °C at Canberra Airport on 30 Nov|
|Warmest days on average||
20.1 °C at Canberra Airport|
|Coolest days on average||
11.0 °C at Mount Ginini AWS|
-2.3 °C at Mount Ginini AWS on 24 Aug|
-10.0 °C at Tidbinbilla Nature Reserve on 5 Jul|
|Coolest nights on average||
2.9 °C at Mount Ginini AWS|
|Warmest nights on average||
6.0 °C at Tuggeranong (Isabella Plains) AWS|
19.3 °C at Tuggeranong (Isabella Plains) AWS on 2 Dec|
|Warmest on average overall||
13.0 °C at Tuggeranong (Isabella Plains) AWS|
|Coolest on average overall||
7.0 °C at Mount Ginini AWS|
1280.8 mm at Mount Ginini AWS|
|Wettest day||107.6 mm at Mount Ginini AWS on 4 Marr|
|Highest wind gust||
98 km/h at Mount Ginini AWS on 10 Aug|
|Record lowest temperature|
in 2012 (°C)
|Tidbinbilla Nature Reserve||-10.0||on 5 Jul||= -10.0||on 28 Jun 1988||28||6.5|
|Summary statistics for 2012|
|Canberra Airport||20.1||+0.4||35.1||30 Nov||5.6||-0.9||-6.8||1 Sep||695.8||616.4||average||113%|
|Mount Ginini AWS||11.0||25.1||29 Nov||2.9||-6.4||10 Aug||1280.8|
|Tuggeranong (Isabella Plains) AWS||20.0||34.5||29 Nov||6.0||-6.2||7 Jul||846.8|
As of March 2010, the official station for Canberra is 70351 'Canberra Airport'. Averages from the previous site, 70014 Canberra Airport Comparison, are used for comparisons (all years of record).
A Annual Climate Summary is prepared to list the main features of the weather in ACT Monthly Summary 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 9 am on Wednesday 2 January 2013. 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.