Wednesday 3 January 2007 - Monthly Climate Summary for Sydney - Product code IDCKGC15L0

Cool and cloudy during December in Sydney


  • 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.



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:


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.


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 Salis
NSW Climate Services Centre
Bureau of Meteorology
Phone (02) 9296 1542


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


Summary statistics for Sydney area for December 2006
Maximum temperatures
for December 2006
Minimum temperatures
for December 2006
for December 2006
Mean for
December 2006
Highest for
Mean for
December 2006
Lowest for
December 2006
Total for
December 2006
Rank of
Fraction of
December normal
Sydney 24.2 −1.3 32.4 14th 17.6 −0.5 13.4


74.2 77.7 normal 95%
Camden 27.7 −0.9 40.0 1st 15.0 0.0 9.1


57.0 52.4 normal 109%
Parramatta 26.6 −0.9 38.5 1st 15.7 −0.5 9.8


67.2 68.4  normal 98%
Richmond 28.3 −0.5 40.5 1st 15.3 0.4 8.5


59.4 71.7 low 83%
Springwood 26.0 38.0 1st 13.9 8.2


52.3 101.5 very low 52%
Terrey Hills 25.2 34.3 1st 15.3 9.6




Summary phenomena for Sydney for December

December 2006

Normal for December

Number of rain days



Average sunshine hours per day*



Average humidity at 3pm (%)



Number of thunderstorms



Number of windy days*




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.