Monday, 1 June 2009 - Seasonal Climate Summary for Canberra rainfall extremes - Product code IDCKGC25x0
Canberra has mild, dry autumn
Summary
Canberra and the ACT had a very mild autumn with below average rainfall. Autumn ended on a very dry note with only 2.4 mm of rain during May.
Main points
- 9th consecutive autumn with below average rainfall.
- 13th consecutive autumn with above average maximum temperatures.
- Below average rainfall
- Mild days with above average maximum temperatures
- Mild nights with above average minimum temperatures
- Sunny autumn with above average sunshine hours
An archive of previous seasonal summaries for Canberra rainfall extremes is also available, as are summaries for other states and many other climate summaries and diagnostics.
Jump to: Extremes Records Summaries Notes the top
Rainfall
The total autumn rainfall of 85.2 mm at Canberra Airport was well below the historical autumn average1 of 140.7 mm. Nearly all of the season's rainfall occurred during April with March and May very dry months. Autumn in Canberra ranked as the 18th driest out of 70 years of record. This is now the 9th consecutive autumn with below average rainfall in the ACT. There were 17 rain days during autumn, below the historic average of 22 rain days. A third of autumn's total rainfall occurred on one day on 14 April when a low pressure trough from the west caused widespread showers and storms over the ACT. However, all other falls during autumn were light and scattered.
The wettest location in the ACT during autumn was at Mount Ginini AWS with a total of 184.8 mm. In the Canberra suburban area the highest was 132.2 mm at Canberra Farrer Pluvio. The driest location was at Chifley with a total of 84.6 mm.
Temperatures
Mild days prevailed in the ACT during autumn. The average1 maximum temperature for autumn at Canberra Airport was 20.9°C, which is 0.9°C above the historical autumn average of 20.0°C. This is the 11th warmest autumn out of 70 years of record in Canberra. It is also the 13th consecutive autumn with above average maximum temperatures in the ACT.
The warm conditions were due to an abundance of sunny days and few significant cool changes. Overnight temperatures were above average with Canberra Airport recording an average minimum temperature of 8.1°C, which is 1.3°C above the historical autumn average of 6.8°C.
Temperature extremes at Canberra Airport ranged from a high of 31.9°C on 24th of March and a low of −0.5°C on 10th of May. The lowest temperature in the ACT during autumn was −5.0°C at Mount Ginini AWS on the 29th following a strong cold front. The lowest in the Canberra metropolitan area was −1.1°C at Tuggeranong on 17 May.
Wind
S-SE winds prevailed over the ACT during Autumn for 48% of the time during mornings. Several days of strong winds were recorded during autumn. The strongest wind gust of 96 km/h from the NNW was recorded at Canberra Airport on 24th April associated with the passage of a cold front. The more exposed mountains to the SW of the city recorded wind gusts of over 100 km/h from the northwest on the 25th (Mount Ginini).
Other phenomena
Sunshine averaged 7.5 hours during autumn which was above the historical average of 7.1 hours per day. During autumn three thunderstorms were reported at Canberra Airport from March to April with none reported in May. On the 15th of April widespread raised dust was reported reducing visibility to only 4 km over the ACT. Snow also fell later in April, with at least 10 cm of snow falling on the mountains to the SW of Canberra between the 26th and 28th and was associated with the passage of a cold front. During May, there were 9 days when fog was observed at the airport or in patches within immediate vicinity. The lowest visibility reported was 300 m at Canberra Airport on 1st of May.
Further information
NSW Climate Services Centre
Bureau of Meteorology
Phone (02) 9296 1555
Email climate.nsw@bom.gov.au
Extremes
| Hottest day Highest temperature |
31.9°C at Canberra Airport on 24 Mar |
|---|---|
| Warmest days on average Highest mean daily maximum temperature |
20.9°C at Canberra Airport |
| Coolest days on average Lowest mean daily maximum temperature |
11.6°C at Mount Ginini AWS 20.8°C at Tuggeranong AWS |
| Coldest day Lowest daily maximum temperature |
12.9°C at Canberra Airport and Tuggeranong on 29 May
−1.7°C at Mount Ginini AWS on 26 Apr |
| Coldest night Lowest temperature | −1.1°C at Tuggeranong AWS on 17 May −5.0°C at Mount Ginini AWS on 29 Apr |
| Coolest nights on average Lowest mean daily minimum temperature |
3.6°C at Mount Ginini AWS 8.1°C at Canberra Airport |
| Warmest nights on average Highest mean daily minimum temperature |
8.2°C at Tuggeranong AWS |
| Warmest night Highest daily minimum temperature |
17.3°C at Tuggeranong AWS on 3 Mar 17.3°C at Tuggeranong AWS on 13 Mar |
| Wettest overall Highest total rainfall |
184.8 mm at Mount Ginini AWS 132.2 mm at Canberra Farrer Pluvio |
| Driest overall Lowest total rainfall | 84.6 mm at Chifley (Waldock Street) |
| Wettest day Highest daily rainfall |
42.6 mm at Canberra Farrer Pluvio on 18 Apr 39.8 mm at Bendora Dam on 5 Mar |
| Highest wind gust |
100 km/h at Mount Ginini AWS on 25 Apr 96 km/h at Canberra Airport on 24 Apr |
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Records
Nil recordedJump to: Extremes Records Summaries Notes the top
Summaries
This table is very wide and may not fit if printed.
| Summary statistics for autumn 2009 | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Maximum temperatures for autumn (°C) |
Minimum temperatures for autumn (°C) |
Rainfall for autumn (millimetres) |
||||||||||
| Mean for autumn 2009 |
Diff from average |
Highest for autumn 2009 |
Mean for autumn 2009 |
Diff from average |
Lowest for autumn 2009 |
Total for autumn 2009 |
Average for autumn |
Rank of autumn 2009 |
Fraction of autumn average |
|||
| Canberra Airport | 20.9 | +0.9 | 31.9 | 24 Mar | 8.1 | +1.3 | −0.5 | 7 May | 85.2 | 140.7 | low | 61% |
| Mount Ginini AWS | 11.6 | 21.0 | 24 Mar | 3.6 | −5.0 | 29 Apr | 184.8 | |||||
| Tuggeranong | 20.8 | −0.4 | 31.7 | 24 Mar | 8.2 | +1.4 | −1.1 | 17 May | 112.2 | 81.2 | average | 138% |
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Notes
This statement has been prepared based on information available at 1 pm on Monday 1 June 2009. Some checks have been made on the data, but it is possible that results will change as new information becomes available.
A note about deciles: Deciles are used to give an element (in this case rainfall or temperature) a ranking. Deciles are calculated by arranging the totals in ascending order (from lowest to highest) then splitting them into 10 equal groups (thus the groups are called deciles). The first group would be in decile range one, the second group in decile range two, etc up to the highest annual totals (highest 10 per cent) being in decile range 10.
1Averages: Averages are based on the period 1961 to 1990 which is a convention of the World Meteorological Organisation
Normals are long-term averages 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 for temperature and less than 30 years of record for rainfall, as they cannot then be calculated reliably.
Further information
NSW Climate Services Centre
Bureau of Meteorology
Phone (02) 9296 1555
Email climate.nsw@bom.gov.au