Monday, 3 December 2007 - Seasonal Climate Summary for Canberra area - Product code IDCKGC2xx0
Canberra has equal warmest spring nights on record
Summary
- warm days, 5th highest average maximum temperature on record
- 4 consecutive springs with above average maximum temperatures
- 54 days exceeded 20°C (normally only 38 days exceeding 20°C)
- warm nights, equal highest average minimum temperature on record (7.8°C or 1.8°C above average and same as 2005)
- 13 consecutive springs with above average minimum temperatures
- 7 nights with minimum temperature above 15°C, the highest on record (normally only 1 night above 15°C)
- below average rainfall
- plentiful sunshine
Jump to: Extremes Summaries Notes the top
Rainfall
The total spring rainfall of 131.2 mm at Canberra Airport was below the historic spring average1 of 178.8 mm. Most of this spring's rainfall occurred during November (94.0 mm) with September and October being mostly dry months. This could be attributed to a delayed rainfall response of the La Nina event established since August in the Pacific Ocean. There were 28 rain days, which is slightly below the historic average of 30 rain days. The highest spring rainfall totals were in western parts of the ACT while central Canberra recorded the lowest falls. Totals ranged from a high of 255.0 mm at Mount Ginini AWS to a low of 112.7 mm at Curtin. The highest suburban total was 183.0 mm at Tuggeranong AWS.
Temperatures
Average maximum temperatures during spring were well above the historic average. The average maximum (daytime) temperature at Canberra Airport was 21.8°C, which is the 5th warmest average maximum temperature on record for spring and 2.5°C above the historic average1 of 19.3°C. An abundance of warm, sunny days with below average rainfall contributed towards the warm conditions. For example there were 54 days when the temperature exceeded 20°C in spring compared to the historic average of 38 days over 20°C. Conditions were significantly cooler in the elevated southern mountain regions of the ACT where the average maximum temperatures at Mount Ginini (elev 1760 m) was 12.4°C for the spring period.
This is the 4th consecutive spring with above average maximum temperatures in Canberra with 7 of the last 8 springs recording above average maximum temperatures.
Average minimum (night-time) temperatures over Canberra were well above the historic spring average. The average minimum temperature at Canberra Airport of 7.8°C was 1.8°C above the historic spring average1 and ranking equal highest on record, and the same as 2005. Canberra experienced a distinct lack of cold nights this spring with only 27 nights falling below 5°C. Normally Canberra would expect around 39 nights below 5°C during spring.
Canberra has now experienced 13 consecutive springs with above average minimum temperatures.
Extremes of temperature across Canberra during spring ranged from a high of 33.4°C at Canberra Airport on 20 and 21 November to a low of −2.5°C at Tuggeranong AWS on 16 and 23 September. In the elevated regions of the ACT the corresponding extremes at Mount Ginini (elev 1760 m) ranged from a high of 24.9°C on 20 November to a low of −5.8°C on 4 September.
Other phenomena
Canberra Airport recorded 20 frosts during spring compared to the historic average of 22 frosts. There was only 2 fogs recorded at the airport, both in September (average 7 fogs). It was generally a very sunny spring with sunshine averaging 8.9 hours per day (historic average 8.4 hours per day). The season was a little windier than usual with 12 strong wind days (average 10) and 1 gale day. The gale occurred on 3 October with tree damage reported in several ACT suburbs. The average wind run was 211 km per day, very close to the historic spring average of 216 km per day.
During spring, there were 11 thunderstorms (average 8) and one hail day (on 26 October) (average 3 hail days) reported at Canberra Airport. The average air pressure of 1016.2 hPA was slightly above the long term average of 1015.3 hPa. Because of the above average temperatures and below average humidity during spring, the evaporation rate has been higher than normal in Canberra with a total of 536 mm compared to the historic average of 467 mm.
Further information
Mike De SalisClimate Information Officer
NSW Climate Services Centre
Bureau of Meteorology
Phone (02) 9296 1555
Email mikede@bom.gov.au
Extremes for the ACT
| Hottest day Highest temperature |
33.4°C at Canberra Airport on 20 Nov and 21 Nov 33.4°C at Tuggeranong AWS on 20 Nov |
|---|---|
| Warmest days on average Highest mean daily maximum temperature |
21.8°C at Canberra Airport |
| Coolest days on average Lowest mean daily maximum temperature |
21.7°C at Tuggeranong AWS |
| Coldest day Lowest daily maximum temperature |
11.9°C at Tuggeranong AWS on 5 Sep 2.0°C at Mount Ginini on 5 and 11 Sep |
| Coldest night Lowest temperature |
−2.5°C at Tuggeranong AWS on 16 Sep and 23 Sep −5.8°C at Mount Ginini on 4 Sep |
| Coolest nights on average Lowest mean daily minimum temperature |
7.1°C at Tuggeranong AWS 3.3°C at Mount Ginini AWS |
| Warmest nights on average Highest mean daily minimum temperature |
7.8°C at Canberra Airport |
| Warmest night Highest daily minimum temperature | 16.4°C at Canberra Airport on 22 Nov |
| Wettest overall Highest total rainfall |
188.6 mm at Tharwa |
| Driest overall Lowest total rainfall |
112.8 mm at Curtin |
| Wettest day Highest daily rainfall | 43.6 mm at Sullivan Creek (Southwell) on 4 Nov |
| Highest wind gust |
94 km/h at Canberra Airport on 3 Oct 104 km/h at Mount Ginini on 1 Oct |
Jump to: Extremes Summaries Notes the top
Summaries for the ACT
| Summary statistics for spring 2007 | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Maximum temperatures for spring (°C) |
Minimum temperatures for spring (°C) |
Rainfall for spring (millimetres) |
||||||||||
| Mean for spring 2007 |
Diff from normal |
Highest for spring 2007 |
Mean for spring 2007 |
Diff from normal |
Lowest for spring 2007 |
Total for spring 2007 |
Normal for spring |
Rank of spring 2007 |
Fraction of spring normal |
|||
| Canberra Airport | 21.8 | +2.5 | 33.4 | 21 Nov | 7.8 | +1.8 | −2.3 | 16 Sep | 131.2 | 178.8 |
low | 73% |
| Tuggeranong | 21.7 | +1.1 | 33.4 | 20 Nov | 7.1 | +0.6 | −2.5 | 16 Sep | 183.0 | 174.8 |
normal | 105% |
| Mount Ginini* | 12.4 | 24.9 | 20 Nov | 3.3 | −5.8 | 4 Sep | 255.0 | - |
||||
* new station, historic averages not available
Jump to: Extremes Summaries Notes the top
Notes
This statement has been prepared based on information available at 2 pm on Monday 3 December 2007. Some checks have been made on the data, but it is possible that results will change as new information becomes available.
1Averages: historic average temperatures for Canberra Airport are based on the period 1961 to 1990 which is a convention of the World Meteorological Organisation. The historic average temperatures for Tuggeranong AWS are based on all available records 1996−2007. Rainfall averages at Canberra Airport are based on all years of record 1939−2007.
Normals 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 10 years of record, as they cannot then be calculated reliably.
The median
is sometimes more representative than the
mean
of "normal" 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,
normal in decile 4 to 7, high in decile 8 or 9
and very high is in decile 10).
The Fraction of normal shows how much rain has fallen this time as a
percentage of the long-term mean.