Wednesday 3 January 2007 - Annual Climate Summary for Sydney - Product code IDCKGC35L0

Year 2006: Maximum temperatures third highest on record for Sydney

Summary

  • Equal 3rd warmest year for average maximum temperatures.
  • Total of 26 hot days when temperature exceeded 30°C (normally 15 days).
  • Mild nights on coast but cool in western suburbs.
  • Below average rainfall but sunshine hours equalled the historic average.

Details

Temperatures

Sydney commenced the year with record high temperatures on 1 January when Observatory Hill recorded a maximum of 44.2°C (2nd highest ever recorded) and Sydney Airport 45.2°C (highest on record).  Sydney experienced its equal third warmest year on record during 2006.   The average maximum (daytime) temperature at Observatory Hill was 23.1°C, well above the historic average1 of 22.1°C and ranking equal 3rd warmest year since records commenced in 1859.  In 2002 and 2001 the average temperature was also 23.1°C.  The warmest year was 2004 with an average of 23.4°C.  The average maximum in the western suburbs was about 1°C warmer than coastal suburbs mainly due to the absence of cooling sea-breezes during the warmer months.  There were 26 hot days (temperature exceeding 30°C) at Observatory Hill during 2006 compared to an historic average of 15 days.  This ranks as the 7th highest in 147 years of record.  The highest was 31 hot days in 1922, followed by 29 days in 1926, 28 days in 1940 and 27 days in 1977,1998 and 2004.  The above average temperatures in Sydney are consistent with above average temperatures over NSW.  The last 7 years have all been above average, a pattern consistent with the observed trend of global rising temperatures.

Average maximum temperatures were consistently above the historic average for all months except June and December.  The greatest departures from normal were in Spring with Sydney recording its second warmest Spring in 147 years of record.  Average maximum temperatures in September were 2.7°C above average (the hottest September on record) and in October they were 2.0°C above.  Record heat also occurred earlier in the year during March (1.9°C above average) and February (1.6°C above).  In contrast Sydney recorded its coldest June in 24 years.

Average minimum (night-time) temperatures at Sydney Observatory Hill were slightly above the historic average1 during 2006.  The average minimum of 14.6°C was 0.4°C above the historic average1.  However, the western suburbs experienced much colder minimum temperatures with an annual average of 10.3°C at Richmond or 0.8°C below the historic average1. This is the lowest since 1982 and the 7th lowest on record (records since 1929).  During winter a total of 41 frosts (temperature below 2°C) were recorded at Richmond compared to the historic average of 27 frosts.  Sydney also experienced a higher than average annual temperature range (difference between annual average maximum and minimum temperatures) away from the coast, where cool nights followed by warm days were typical.  Richmond recorded an annual range of 14.0°C, its 3rd greatest range since records commenced in 1929.  The highest was 14.4° in 1944. Both the low minimum temperatures and the high annual temperature range were a product of clear skies and low humidity which allowed heating by day and maximum cooling at night.

The highest temperature at Sydney Observatory Hill during 2006 was 44.2°C on 1 January while the lowest temperature was 5.8°C on 12 June.  Corresponding annual extremes across the Sydney metropolitan area ranged from 45.2°C at Sydney Airport on 1 January to −3.3°C at Richmond on 9 July.

Rainfall

The total annual rainfall of 994.0 mm at Observatory Hill was below the historic annual average of 1217 mm and ranks in the lowest 30% of totals.  There were 136 rain days during the year which is close to the historic average of 138 rain days.  Almost two-thirds of the rain fell from June to September with generally well below average rainfall for all other months. However, the western suburbs were much drier than the coast and significantly below average in the west and south-west.  Although Sydney Observatory Hill received 994.0 mm for 2006 (82% of the normal), Richmond received only 490.6 mm (60% of the normal).  This rainfall distribution over the metropolitan area has followed a similar pattern since late Autumn with coastal suburbs receiving reasonable falls but the rain failing to penetrate inland.  Annual rainfall extremes ranged from 1149.0 mm at Rose Bay in the eastern suburbs to only 475 mm at Camden in the far south-west.

Sydney's Warragamba Dam catchment area also received well below average rainfall during 2006, especially during Autumn when only 43 mm was recorded.  The only months to receive significantly above average rainfall were January (165 mm) and September (78 mm).

Other phenomena

The amount of sunshine for Sydney during 2006 averaged 7.2 hours per day which equals the historic average.  However, monthly averages varied considerably from 9.3 hours per day in April (the sunniest April on record) to only 5.2 hours per day in June.

Windy conditions persisted in coastal suburbs during the year with 83 windy days recorded at Sydney Airport, the highest since 1996.  The historic average is 57 windy days. Many of these windy days were associated with southerly changes or strong NE sea-breezes.    Gale force winds on 24 September caused widespread damage and power failures in western Sydney with bushfires destroying at least 6 houses.  Winds reached 109 km/h at Camden.  Further large bushfires west and north of Sydney during November caused thick smoke haze over the metropolitan area with visibility reduced to 5 km at times.

During the year Sydney recorded 22 thunderstorms compared to the historic average of 23 storms.  On 15 August a thunderstorm with heavy hail accumulated to a depth of several centimetres in the inner west and the CBD area.

Further information

Mike De Salis
NSW Climate Services Centre
Bureau of Meteorology
Phone (02) 9296 1542
Email reqnsw@bom.gov.au

Perry Wiles
NSW Climate Services Centre
Bureau of Meteorology
Phone (02) 9296 1525


Extremes in Sydney area for 2006

Hottest day
Highest temperature
45.2°C at Sydney Airport on 1 Jan
Warmest days on average
Highest mean daily maximum temperature
25.0°C at Penrith Lakes
Coolest days on average
Lowest mean daily maximum temperature
22.0°C at Terrey Hills and Springwood
Coldest day
Lowest daily maximum temperature
10.4°C at Terrey Hills on 19 July
Coldest night
Lowest temperature
−3.3°C at Richmond on 9 July
Coolest nights on average
Lowest mean daily minimum temperature
10.0°C at Camden
Warmest nights on average
Highest mean daily minimum temperature
14.6°C at Sydney (Observatory Hill)
Warmest night
Highest daily minimum temperature
27.2°C at Terrey Hills on 22 Nov
Wettest overall
Highest total rainfall
1149.0 mm at Rose Bay
Driest overall
Lowest total rainfall
475.0 mm at Camden
Wettest day
Highest daily rainfall
118.0 mm at Palm Beach on 27 Feb
Highest wind gust
109 km/h at Camden on 24 Sep

 

Record highest annual temperature
Highest temperature
for 2006 (°C)
Previous annual
highest
Normal
annual
Years of
record
Sydney Airport 45.2 on 1 Jan 43.4 25 Nov 1982 22.2 68
Parramatta 44.8 on 1 Jan 44.5 18 Jan 2003 23.2
29

Summaries

Summary statistics for Year 2006
Maximum temperatures
(°C)
Minimum temperatures
(°C)
Rainfall
(millimetres)
Mean
for
2006
Diff
from
normal
Highest
for
2006
Mean
for
2006
Diff
from
normal
Lowest
for
2006
Total
for
2006
Normal
annual
total
Rank
of
2006
Fraction
of annual
normal
Sydney (Observatory Hill) 23.1 +1.0 44.2 1 Jan 14.6 +0.4 5.8 12 Jun 994.0 1216.6 low 82%
Richmond 24.4 +0.7 43.8 1 Jan 10.3 −0.8 −3.3 9 Jul 490.6 821.5 very low 60%
Parramatta 24.0 +0.8 44.8 1 Jan 12.2 +0.1 2.0 15 Jun 761.1 961.8 low 79%
Terrey Hills 22.0 43.3 1 Jan 12.9 3.4 9 Jul 762.6  
Camden 24.4 +0.8 44.0 1 Jan 10.0 −0.1 −3.1 11 Jul 475.0 792.8 very low 60%
Springwood 22.0 38.0 1 Dec 10.1 −0.3 15 Jun 684.7 1086.7 very low 63%

 

Summary phenomena for Sydney for Year 2006
 

Year 2006

Normal for year

Number of rain days

136

138

Average sunshine hours per day*

7.2

7.2

Average humidity at 3pm (%)

56

57

Number of thunderstorms

22

23

Number of windy days*

 83

57

* recorded at Sydney Airport.  Windy day defined as average speed of 40km/h or more at synoptic times.


Notes

This statement has been prepared based on information available at noon 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.