Wednesday 3 January 2007 - Monthly Climate Summary for Sydney - Product code IDCKGC15L0
Cool and cloudy during December in Sydney
Summary
- Below average temperatures. Average maximum lowest since 1999, average minimum lowest since 1996.
- Close to average rainfall.
- Well below average sunshine.
- Windy along the coast.
Jump to: Extremes Records Summaries Notes the top
Details
Rainfall
The total monthly rainfall of 74.2 mm at Observatory Hill was close to the historic December average of 77.8 mm. There were 12 rain days, which was slightly above the historic average of 11 rain days. Metropolitan rainfall totals were highest in the inner west and eastern suburbs with December totals ranging from 105.8 mm at Canterbury in Sydney's inner west to only 37 mm at Box Hill in the far north-west.
Rainfall in the Warragamba Dam catchment area during December ranged from 60−80 mm over the lower catchment to around 40 mm in the Goulburn (upper catchment) area. Recent rainfall in Sydney's catchments can be found on the Sydney Catchment Authority web site at: http://www.sca.nsw.gov.au/dams/rainfall.html
Temperature
The average maximum temperature at Observatory Hill was 24.2°C, or 1.3°C below the historic average1 of 25.5°C. This is the coolest since 1999 when an average of 23.6°C was recorded. There were only 2 hot days (temperature exceeding 30°C) compared to the historic average of 3 hot days. Far western suburbs recorded average maximum temperatures about 4°C warmer than coastal suburbs due mainly to the absence of cooling sea-breezes. Although the average maximum at Richmond was 28.3°C, it was still 0.5°C below the historic average. Cloudy skies and prevailing southerly winds contributed toward the cooler temperatures.
Nights were also quite cool during December, especially along the coast. The average minimum temperature at Sydney Observatory Hill of 17.6°C was 0.5°C below the historic average. This is the coolest since 1996 when 17.1°C was recorded. Even cooler nights were experienced away from the coast with Camden recording an average minimum of 15.0°C. At Springwood (elevation 362 metres) the average minimum was 13.9°C, the lowest in the Sydney area.
The highest temperature at Sydney Observatory Hill during December was 32.4°C on the 14th while the lowest was 13.4°C on the 4th. Corresponding extremes across the Sydney metropolitan area ranged from 40.5°C at Richmond on the 1st to 7.0°C at Holsworthy on the 26th which was a 9 year December low for Holsworthy. The minimum temperature at Liverpool on the 26th was 7.8°C, the lowest December minimum since 1964.
Wind
Strong winds were recorded along the coast during December with 14 windy days at Sydney Airport, twice the historic average of 7 days. This was due mainly to the persistence of fresh sea-breezes and numerous southerly changes. However, wind strengths dropped off rapidly away from the coast with 2 windy days recorded at Bankstown and only 1 windy day in the far west at Richmond.
Other phenomena
There were 14 cloudy days during December compared to an historical average of 13 days. Sunshine averaged 6.9 hrs/day which is well below the average of 8.0 hrs/day.
Further information
Mike De SalisNSW Climate Services Centre
Bureau of Meteorology
Phone (02) 9296 1542
Email reqnsw@bom.gov.au
Extremes
| Hottest day Highest temperature |
40.5°C at Richmond on the 1st |
|---|---|
| Warmest days on average Highest mean daily maximum temperature |
29.3°C at Penrith |
| Coolest days on average Lowest mean daily maximum temperature |
24.2°C at Sydney (Observatory Hill) |
| Coldest day Lowest daily maximum temperature |
14.8°C at Springwood on the 12th |
| Coldest night Lowest temperature |
7.0°C at Holsworthy on the 26th |
| Coolest nights on average Lowest mean daily minimum temperature |
13.9°C at Springwood |
| Warmest nights on average Highest mean daily minimum temperature |
17.6°C at Sydney (Observatory Hill) |
| Warmest night Highest daily minimum temperature |
21.2°C at Penrith on the 23rd |
| Wettest overall Highest total rainfall | 105.8 mm at Canterbury |
| Driest overall Lowest total rainfall | 37.0 mm at Box Hill |
| Wettest day Highest daily rainfall | 39.6 mm at Canterbury on the 20th |
| Highest wind gust |
81 km/h at Sydney Airport on the 11th |
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Summaries
| Summary statistics for Sydney area for December 2006 | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Maximum temperatures for December 2006 (°C) |
Minimum temperatures for December 2006 (°C) |
Rainfall for December 2006 (millimetres) |
||||||||||
| Mean for December 2006 |
Diff from normal |
Highest for December 2006 |
Mean for December 2006 |
Diff from normal |
Lowest for December 2006 |
Total for December 2006 |
Normal for December |
Rank of December |
Fraction of December normal |
|||
| Sydney | 24.2 | −1.3 | 32.4 | 14th | 17.6 | −0.5 | 13.4 |
4th |
74.2 | 77.7 | normal | 95% |
| Camden | 27.7 | −0.9 | 40.0 | 1st | 15.0 | 0.0 | 9.1 |
26th |
57.0 | 52.4 | normal | 109% |
| Parramatta | 26.6 | −0.9 | 38.5 | 1st | 15.7 | −0.5 | 9.8 |
17th |
67.2 | 68.4 | normal | 98% |
| Richmond | 28.3 | −0.5 | 40.5 | 1st | 15.3 | 0.4 | 8.5 |
26th |
59.4 | 71.7 | low | 83% |
| Springwood | 26.0 | 38.0 | 1st | 13.9 | 8.2 |
26th |
52.3 | 101.5 | very low | 52% | ||
| Terrey Hills | 25.2 | 34.3 | 1st | 15.3 | 9.6 |
26th |
54.4 | |||||
| Summary phenomena for Sydney for December | ||
|---|---|---|
| December 2006 |
Normal for December |
|
| Number of rain days |
12 |
11 |
| Average sunshine hours per day* |
6.9 |
8.0 |
| Average humidity at 3pm (%) |
60 |
59 |
| Number of thunderstorms |
4 |
4 |
| Number of windy days* |
14 |
7 |
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Notes
This statement has been prepared based on information available at 1 pm on Tuesday 2 January 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 Observatory Hill and Richmond are based on the period 1961 to 1990 which is a convention of the World Meteorological Organisation. Average temperatures for Parramatta are based on all available data, 1968 - 2005 and Camden 1972 - 2005. Rainfall averages and extremes for Observatory Hill are based on all years of record 1859 - 2005.
The Rank indicates about where rainfall this time ranks in the climate record for the site.