Thursday, 2 December 2010 - Seasonal Climate Summary for ACT Monthly Summary - Product code IDCKGC25R0

Canberra's wettest spring since 1983

  • 4th wettest spring on record
  • Wettest spring since 1983, and wettest season since winter 1998
  • Well above average minimum temperatures; 16th consecutive spring with above average minimums

Details Extremes Records Summaries Important notes the top

Rainfall

Canberra Airport recorded a total rainfall of 288.0 mm during spring 2010, which is well above the historical average of 178.2 mm and more than double the rainfall recorded in spring 2009 (117.8 mm). This is the wettest season since winter 1998, when 305.8 mm was recorded at Canberra Airport. Spring 2010 ranks as the 4th wettest spring on record and the wettest spring since 1983, when 289.6 mm of rainfall was recorded. The majority of the rainfall fell in October and November, both of which had monthly totals exceeding 100 mm; however, all three months had above average rainfall.

The rain fell over 27 rain days, which is slightly below the spring average of 30 raindays. Two major events brought daily totals above 25 mm to Canberra Airport during the month, with 38.6 mm recorded on the 14th of October as a slow moving trough crossed the city, with four-day totals of 78.8 mm between the 13th and 16th. The season also concluded with very wet conditions, with 40.6 mm recorded on November 29th as a front crossed the state. The highest daily rainfall recorded during the season was 73.4 mm at Mt Ginini AWS on October 16, with total spring rainfall of 608.6 mm at Mt Ginini, the highest in the ACT.

Tharwa General Store and Tidbinbilla Nature Reserve also recorded their highest total spring rainfall on record during this season. The high rainfall experienced in the ACT is consistent with Australia-wide patterns, with NSW recording its wettest spring on record and Australia as a whole recording its wettest spring on record. These patterns are consistent with both the La Niña event in the Pacific Ocean and a negative Indian Ocean Dipole event, both of which bring increased rainfall to eastern Australia, particularly in inland regions. For more about La Niña and the IOD please refer to the ENSO Wrap Up.

Some sites had their highest total spring rainfall on record.

Temperature

The average maximum temperature for spring at Canberra Airport was 19.5 °C, close to the historical average of 19.4 °C, with the highest average maximum temperature anywhere in Canberra just 19.7 °C at Tuggeranong AWS. This is the coolest spring since 2003 (19.2 °C), with all spring months having near average maximum temperatures.

The average daily minimum temperature during spring was 7.0 °C at Canberra Airport, which is 1 °C above the historical average of 6 °C and the warmest average minimum temperatures in suburban ACT. Canberra Airport has now experienced 16 consecutive springs with above average minimum temperatures. All months during spring had above average minimums, leading to slightly above average mean daily temperatures for the season.

The highest temperature in the ACT during spring was 28.2 °C at Tuggeranong on November 12, while the lowest temperature was -5.5 °C at Mt Ginini AWS on October 16, a much smaller temperature range than in Spring 2009 (-6.1 °C to 38.2 °C). The lowest temperature in suburban Canberra was -2.0 °C at Tuggeranong AWS on September 30.

Wind

The highest wind gust recorded at Canberra Airport during spring was 85km/hr on September 4, with a maximum wind gust of 109km/hr at Mt Ginini AWS on the same day. Eight strong wind days were recorded during the season, slightly below the historical average of 11 days, with no strong wind days recorded in November.

Other phenomena

The mean daily sunshine during spring was 7.6 hours, well below the historical average of 8.4 hours per day. There were 7 frosts, well below the historical average of 22, and 24 fogs. This was well above the historical average of 8 fogs, with September the equal foggiest on record. Three thunderstorms were recorded at Canberra Airport, well below the historical average of eight thunder days, with hail reported on November 8.

Further information

Climate Officer
NSW Climate Services Centre
NSW Regional Office
Bureau of Meteorology
Phone (02) 9296 1555
Email climate.nsw@bom.gov.au
Extremes in spring 2010
Hottest day 28.2 °C at Tuggeranong (Isabella Plains) AWS on 12 Nov
Warmest days on average 19.6 °C at Tuggeranong (Isabella Plains) AWS
Coolest days on average 11.1 °C at Mount Ginini AWS
Coldest day -1.2 °C at Mount Ginini AWS on 16 Oct
Coldest night -5.5 °C at Mount Ginini AWS on 16 Oct
Coolest nights on average 2.7 °C at Mount Ginini AWS
Warmest nights on average 7.6 °C at Canberra Airport Comparison
Warmest night 19.5 °C at Canberra Airport on 15 Nov
Wettest overall 608.6 mm at Mount Ginini AWS
Wettest day 73.4 mm at Mount Ginini AWS on 16 Oct
Highest wind gust 109 km/h at Mount Ginini AWS on 4 Sep

Details Extremes Records Summaries Important notes the top

Record highest total spring rainfall
Total rainfall
for spring 2010 (mm) 		Previous highest
for spring		 Years of
record		 Average for
spring
Tharwa General Store 362.0 355.5 in 1974 65 187.8
Tidbinbilla Nature Reserve 478.1 467.4 in 1983 43 266.1


Details Extremes Records Summaries Important notes the top

Summary statistics for spring 2010
Maximum temperatures
for spring
(°C)		 Minimum temperatures
for spring
(°C)		 Rainfall
for spring
(millimetres)
Mean for
spring
2010		 Diff
from
average		 Highest for
spring
2010		 Mean for
spring
2010		 Diff
from
average		 Lowest for
spring
2010		 Total for
spring
2010		 Average
for
spring		 Rank of
spring
2010		 Fraction of
spring
average
Southern Tablelands (Goulburn-Monaro) (district 70)
Canberra Airport 19.5   27.7 13 Nov 7.0   -1.9 30 Sep 288.0
Canberra Airport Comparison 19.4 0.0 28.1 12 Nov 7.6 +1.6 -1.0 30 Sep 224.0 178.8 average 125%
Mount Ginini AWS 11.1   20.5 12 Nov 2.7   -5.5 16 Oct 608.6
Tidbinbilla Nature Reserve 18.6 -0.2 27.2 12 Nov 7.5 +1.3 -2.0 1 Oct 478.1 266.1 highest 180%
Tuggeranong (Isabella Plains) AWS 19.6   28.2 12 Nov 7.3   -2.0 30 Sep 398.6

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 11 am on Thursday 2 December 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

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