Monday, 1 March 2010 - Seasonal Climate Summary for ACT Monthly Summary - Product code IDCKGC25R0

ACT in Summer 2009-10: Warm summer comes to a wet end

  • The highest average minimum temperatures at Canberra Airport since 1980
  • 2nd warmest mean temperatures on record
  • 8th warmest maximum temperatures on record
  • Above average rainfall, with wettest summer day since 2002

Details Extremes Records Summaries Important notes the top

Rainfall

The total summer rainfall at Canberra Airport was 209.2mm, well above the historical average of 167.3mm and the highest rainfall since Summer 2007/08. However, only 17 rain days were recorded, below the historical average of 22 rain days. The majority of the rain fell during December and February, with only 7.4mm recorded in January. February in particular recorded well above average rainfall with 125.4mm, the wettest since 2002. The majority of the rainfall was associated with a low pressure trough and upper level low between the 13th and 15th of February, with 104.2mm recorded over three days. This system brought high totals to much of NSW, with heavy rain falling in a band stretching SE to NW across the state.

The highest total rainfall in the Canberra region was 260.4mm at Mt Ginini, with 244.3mm recorded in the suburb of Nicholls. The wettest day recorded was also at Nicholls (Gungahlin Lakes) with 70mm on 14 Feb 2010. Canberra Airport also recorded 56.2mm on this day, the wettest summer day since the 5th of February 2002. Some minor flooding was associated with this event, although no significant damage occurred.

Temperature

Warm temperatures prevailed in Canberra during summer, with above average temperatures recorded in all months including the second warmest January on record. The mean maximum temperature at Canberra Airport was 29.2°C, which is 2.1°C above the historical summer average of 27.1°C. The average minimum temperature was 14.7°C, which was 2.2°C above the historical summer average of 12.5°C and the second warmest on record. Only Summer 1980/81 was warmer, with an average of 14.8°C. This is the 10th consecutive summer with above average minimum temperatures at Canberra Airport. The mean summer temperature was 22°C, making this second warmest summer on record for mean daily temperature, following 22.2°C in Summer 2005/6.

The warmest night recorded was 24.5°C on January 23rd. This was the highest minimum temperature on record at this station, exceeding the previous record by 2°C. The hottest day in Canberra was 39.1°C at Canbeera Airport on the 12th of January, while the coldest nights recorded were 3.5°C at Tidbinbilla on January 19 and -1.7°C at Mt Ginini (elevation 1760m) on December 1.Twelve very hot days (above 35°C) were recorded during Summer, all during December and January. This is the third highest December-January total on record, and the highest since 13 days in 1973/73. Heatwave conditions affected Canberra twice, with two periods of three or more days above 35°C from January 9-12 and January 21-23.

Some sites had their warmest summer night (highest daily minimum temperature) on record. Some sites had their highest summer mean daily minimum temperature for at least 20 years.

Wind

8 strong wind days were recorded during summer, slightly above the historical average of 5, the majority of which occurred during December. The highest wind gust recorded was 78km/hr at both Canberra Airport and Mt Ginini on February 17th. The prevailing winds at Canberra Airport during summer afternoons were north to west (57%). This was particularly true during December and January, with such winds 65% of the time, compared to only 39% in February.

Other phenomena

5 thunderstorms were recorded at Canberra Airport during summer, well below the historical average of 12, with no hail recorded. The summer was generally sunny, with a daily average of 9.9 sunshine hours, above the historical average of 9.3 hours. However, below average sunshine was recorded in February, with only 8.3 hours. Average relative humidity was 61.7% at 9am and 33.4% at 3pm, slightly below the historical average.

Further information

NSW Climate Services Centre
NSW Regional Office
Bureau of Meteorology
Phone (02) 9296 1555
Email climate.nsw@bom.gov.au

Extremes in summer 2009-10

Hottest day

39.1 °C at Canberra Airport on 12 Jan 2010

Warmest days on average

29.2 °C at Canberra Airport

Coolest days on average

19.8 °C at Mount Ginini AWS

Coldest day

7.6 °C at Mount Ginini AWS on 18 Jan 2010

Coldest night

-1.7 °C at Mount Ginini AWS on 1 Dec 2009
3.5 °C at Tidbinbilla Nature Reserve on 19 Jan 2010
4.2 °C at Canberra Airport on 19 Jan 2010

Coolest nights on average

9.1 °C at Mount Ginini AWS
14.7 °C at Canberra Airport

Warmest nights on average

14.8 °C at Tuggeranong (Isabella Plains) AWS

Warmest night

24.5 °C at Tidbinbilla Nature Reserve on 23 Jan 2010

Wettest overall

260.4 mm at Mount Ginini AWS
244.3 mm at Nicholls (Gungahlin Lakes)
231.2 mm at Tuggeranong (Isabella Plains) AWS

Wettest day

70.0 mm at Nicholls (Gungahlin Lakes) on 14 Feb 2010
56.2 mm at Canberra Airport on 14 Feb 2010
54.0 mm at Tuggeranong (Isabella Plains) AWS on 14 Feb 2010

Highest wind gust

78 km/h at Canberra Airport on 17 Dec 2009
78 km/h at Mount Ginini AWS on 17 Dec 2009

Details Extremes Records Summaries Important notes the top

Record highest summer daily minimum temperature

 

Highest daily minimum
temperature
in summer 2009-10 (°C)

Previous highest
for summer

Years of
record

Average for
summer

Tidbinbilla Nature Reserve

24.5

on 23 Jan 2010

22.5

on 27 Feb 1998

26

11.8

 

 

Highest summer mean daily minimum temperature for at least 20 years

 

Mean daily minimum
temperature
for summer 2009-10 (°C)

Most recent higher
for summer

Years since
higher

Average for
summer

Canberra Airport

14.7

14.8

in 1980

29

12.5

 

Details Extremes Records Summaries Important notes the top

Summary statistics for summer 2009-10

 

Maximum temperatures
for summer
(°C)

Minimum temperatures
for summer
(°C)

Rainfall
for summer
(millimetres)

Mean for
summer
2009-10

Diff
from
average

Highest for
summer
2009-10

Mean for
summer
2009-10

Diff
from
average

Lowest for
summer
2009-10

Total for
summer
2009-10

Average
for
summer

Rank of
summer
2009-10

Fraction of
summer
average

Canberra Airport

29.2

+2.1

39.1

12 Jan 2010

14.7

+2.2

4.2

19 Jan 2010

209.2

168.7

high

124%

Mount Ginini AWS

19.8

 

27.9

12 Jan 2010

9.1

 

-1.7

1 Dec 2009

260.4

 

 

 

Tuggeranong (Isabella Plains) AWS

 

 

38.6

12 Jan 2010

14.8

 

4.3

19 Jan 2010

231.2

 

 

 

Details Extremes Records Summaries Important notes the top

Notes

A Seasonal 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 10 am on Monday 1 March 2010. 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

NSW Climate Services Centre
NSW Regional Office
Bureau of Meteorology
Phone (02) 9296 1555
Email climate.nsw@bom.gov.au