Canberra in December 2010: 2nd wettest December on record

  • 2nd wettest December on record.
  • Wettest start to December on record.
  • Wettest December day on record (3rd).
  • Foggiest December since 1960.

Rainfall

Canberra Airport experienced its 2nd wettest December on record (records since 1939), with a total of 198.4 mm during December. This is well above the historical average of 53.8 mm, and the wettest December since 1947 (215.2 mm, wettest on record). The rain fell on 12 days, with the most significant falls on the 1st - 5th , totalling 138.8 mm. This was the wettest start to December on record for Canberra, with the wettest December day ever recorded at Canberra Airport on the 3rd (87.0 mm). The 3rd was also the wettest day (in any month) in Canberra since January 21st 1995, when 93.8 mm was recorded.

Throughout the ACT, December totals were as high as 253.4mm at Tuggeranong, with daily rainfall reaching 93.4mm at Nicholls on the 3rd. Additionally, Tharwa General Store and the Canberra Botanical Gardens experienced their wettest December on record during 2010. The heavy rainfall resulted in flooding in the ACT region, including the inundation of the nearby city of Queanbeyan.

Some sites had their highest total December rainfall on record.

Temperature

The average maximum temperature for Canberra Airport was 25.0°C , which is below the historical average of 26.1°C and the coolest December since 1999 (24.5°C). Temperatures were consistently cool until the last days of the month, with the only two days above 30°C (average 7 days) occuring on the 30th and 31st, reaching 34.8°C at Tuggeranong on the latter. Temperatures were particularly cold on the 20th, with a maximum of just 17.7°C, the coldest December day since 2006 (17.3°C).

The average minimum temperature for Canberra Airport was 11.7°C, which is slightly above the historical average of 11.4°C but significantly cooler than the December 2009 average of 12.5°C. The warmest night was just 18.3°C on the 9th, with no other days exceeding 17°C. Night-time temperatures were coolest on the night of the 18th, when Canberra Airport recorded a minimum temperature of 4.7°C - the lowest December minimum since 2004 (4.1°C on the 29th).

Wind

Canberra Airport experienced prevailing northwesterly winds during December, with a frequency of 58% from this direction at 3pm, close to average for December. The highest wind gust at Canberra Airport was 76 km/hr on the 8th, with no strong wind days reported during December, the first December without strong winds since 1995 (historical average 3 days).

Other phenomena

Canberra Airport averaged 9 hours of sunshine per day during December 2010, slightly below the historical average of 9.4 hours. Six thunderstorms were reported at the airport, slightly above the historical average of 4 thunderstorms, with 12 reported in the whole ACT region, including hail on the 2nd. Six fogs were also reported, well above the December average of one fog and the foggiest December since 1960 (6 fogs).

Further information

Media
(03) 9669 4057
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Extremes in December 2010
Hottest day 34.8 °C at Tuggeranong (Isabella Plains) AWS on the 31st
Warmest days on average 25.0 °C at Canberra Airport
Coolest days on average 15.6 °C at Mount Ginini AWS
Coldest day 5.2 °C at Mount Ginini AWS on the 20th
Coldest night -1.3 °C at Mount Ginini AWS on the 20th
4.7 °C at Canberra Airport on the 19th
Coolest nights on average 6.4 °C at Mount Ginini AWS
Warmest nights on average 12.1 °C at Tuggeranong (Isabella Plains) AWS
Warmest night 18.5 °C at Tuggeranong (Isabella Plains) AWS on the 9th
Warmest on average overall 18.5 °C at Tuggeranong (Isabella Plains) AWS
Coolest on average overall 11.0 °C at Mount Ginini AWS
Wettest overall 253.4 mm at Tuggeranong (Isabella Plains) AWS
Wettest day 93.4 mm at Nicholls (Gungahlin Lakes) on the 3rd
93.0 mm at Tuggeranong (Isabella Plains) AWS on the 9th
Highest wind gust 87 km/h at Mount Ginini AWS on the 18th
76 km/h at Canberra Airport on the 8th

Record highest total December rainfall
Total rainfall
for December 2010 (mm)
Previous wettest
for December
Years of
record
Average for
December
Tharwa General Store 220.4 159.6 in 1961 66 52.0
Canberra (Australian National Botanic Ga 145.0 143.6 in 1999 43 57.8


Summary statistics for December 2010
Maximum temperatures
for December
(°C)
Minimum temperatures
for December
(°C)
Rainfall
for December
(millimetres)
Mean for
December
2010
Diff
from
average
Highest for
December
2010
Mean for
December
2010
Diff
from
average
Lowest for
December
2010
Total for
December
2010
Average
for
December
Rank of
December
2010
Fraction of
December
average
Canberra Airport 25.0 -1.1 33.9 31st 11.7 +0.3 4.7 19th 198.4 53.8 v high
Mount Ginini AWS 15.6   25.8 31st 6.4   -1.3 20th 242.6
Tidbinbilla Nature Reserve 22.9 -2.2 28.0 26th 11.3 +0.5 5.5 19th 132.9 64.3 high 207%
Tuggeranong (Isabella Plains) AWS 24.9   34.8 31st 12.1   5.4 19th 253.4

Notes

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 Monthly 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 12 pm on Tuesday 4 January 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 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 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.

Further information

Media
(03) 9669 4057
Enquiries