Thursday 1 May 2008 - Monthly Climate Summary for Canberra - Product code IDCKGC1xx0
A cool end to April in Canberra
Summary
- Close to average maximum temperatures, cooler than average minimum temperatures
- Below average rainfall
- Cold and snowy end to the month
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Rainfall
Canberra Airport recorded a total rainfall of only 17.4 mm during April, which is well below the historical average1 of 46.4 mm, falling within decile 3. There were only 5 rain days during the month, compared to the historic average of 7 days. Monthly totals around the ACT ranged from a high of 41.4 mm at Mount Ginini AWS, to a low of 8.2 mm at Torrens (Darke St).
The month of April was characterised by persistent high pressure over the region. Rainfall was below average over the whole ACT region due to this stable pattern. Nearly all of Canberra's rainfall during April occurred due to the passage of cold fronts on the 2nd, 12th/13th, and on the 26th/27th. The last of these fronts was particularly vigorous, with snow reported on the Brindabella's behind the change.
Temperatures
Close to average temperatures prevailed over the ACT during April. The mean maximum temperature for Canberra Airport was 19.5 ºC, which is just below the historical average2 of 19.9 °C. The highest temperature in the ACT was 24.1 °C at both Canberra Airport and Tuggeranong on the 12th. A cold spell towards the end of the month saw maximum temperatures drop to 11.3 °C on the 28th at Canberra Airport, the coldest April day since 1999 (11.3 °C on the 27th) . It reached a maximum of only -2.0 °C at Mt Ginini (elevation 1760 m) on the same day.
The average minimum temperature at Canberra Airport was 5.2 ºC, cooler than the historical average of 6.8 ºC. On the 29th, the temperature dropped to -2.1 °C at the Airport. Colder April conditions were experienced in 2006, where the minimum temperature reached -3.4 °C (on the 22nd). The coldest conditions recorded in the ACT in April was at Mt Ginini, where the minimum temperature dropped to -5.0 ºC.
The mean temperature (average of maximum and minimum temperature) was 12.3 °C, well below the historical average of 13.4 °C.
Wind
The prevailing direction over the ACT during the mornings (9am) was from the south to southeast, observed around 70% of the time. This is significantly higher than the normal frequency from these directions at this time. However, during the afternoon the wind was similar to long term conditions, with the prevailing wind direction being from the northwest about 33% of the time. The highest wind gust recorded was 83 km/hr at Canberra Airport on the 2nd, associated with the passage of a cold front.
Other phenomena
Canberra averaged 8 hours of sunshine per day, which is above the historical average of 7.3 hours. There was one thunderstorm reported at Canberra Airport during April on the 13th (historical average 1.2), and one day with hail on the 27th.
Further information
Louise GarbersNSW Climate Services Centre
Bureau of Meteorology
Phone (02) 9296 1555
Email reqnsw@bom.gov.au
Extremes for the ACT
| Hottest day Highest temperature |
24.1 °C at Canberra Airport on the 12th 24.1 °C at Tuggeranong (Isabella Plains) AWS on the 12th |
|---|---|
| Warmest days on average Highest mean daily maximum temperature |
19.6 °C at Tuggeranong (Isabella Plains) AWS |
| Coolest days on average Lowest mean daily maximum temperature |
10.5 °C at Mount Ginini AWS |
| Coldest day Lowest daily maximum temperature |
-2.0 °C at Mount Ginini AWS on the 28th |
| Coldest night Lowest temperature |
-5.0 °C at Mount Ginini AWS on the 29th |
| Coolest nights on average Lowest mean daily minimum temperature |
2.0 °C at Mount Ginini AWS |
| Warmest nights on average Highest mean daily minimum temperature |
5.2 °C at Canberra Airport |
| Warmest night Highest daily minimum temperature |
9.4 °C at Tuggeranong (Isabella Plains) AWS on the 18th |
| Wettest overall Highest total rainfall |
41.4 mm at Mount Ginini AWS |
| Wettest day Highest daily rainfall |
18.2 mm at Canberra (Corin Dam (Boat Ramp)) on the 3rd |
| Highest wind gust |
83 km/h at Canberra Airport on the 2nd |
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Records
| Record lowest April daily maximum temperature | ||||||
|---|---|---|---|---|---|---|
| Lowest daily maximum temperature in April 2008 (°C) |
Previous lowest for April |
Years of record |
Normal for April |
|||
| Tidbinbilla Nature Reserve | 5.0 | on the 27th | 8.0 | on the 7th in 1995 | 23 | 19.1 |
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Summaries for the ACT
| Summary statistics for April 2008 | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Maximum temperatures for April (°C) |
Minimum temperatures for April (°C) |
Rainfall for April (millimetres) |
||||||||||
| Mean for April 2008 |
Diff from normal |
Highest for April 2008 |
Mean for April 2008 |
Diff from normal |
Lowest for April 2008 |
Total for April 2008 |
Normal for April |
Rank of April 2008 |
Fraction of April normal |
|||
| Canberra Airport | 19.5 | -0.5 | 24.1 | 12th | 5.2 | -1.5 | -2.1 | 29th | 17.4 | 46.0 | low | 38% |
| Tuggeranong* | 19.6 | -1.8 | 24.1 | 12th | 4.4 | -2.3 | -3.0 | 30th | 11.4 | 23.4 | normal | 49% |
* historic averages for Tuggeranong based on short period 1996-2007.
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Notes
This statement has been prepared based on information available at 11am Thursday 1 May 2008. Some checks have been made on the data, but it is possible that results will change as new information becomes available.
1Historic rainfall averages for Canberra Airport are based on all years of record 1939 - 2008.
2Historic average temperatures for Canberra Airport are based on the period 1961 to 1990 which is a convention of the World Meteorological Organisation.
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.
Further information
NSW Climate Services CentreBureau of Meteorology
Phone (02) 9296 1555
Email reqnsw@bom.gov.au