Record consecutive warm nights in Sydney during summer

  • Record 18 consecutive warm nights in summer
  • Second warmest summer on record for overnight minimum temperatures
  • 52 nights above 20.0 °C - second highest on record

Rainfall

Sydney experienced above average rainfall during summer. Observatory Hill's total of 342.2 mm was slightly above the historical summer average1 of 297.2 mm. This is the highest summer rainfall for Sydney since 2007/2008 when 438.6mm was recorded.

The majority of Sydney's summer rainfall fell during February and was associated with moist onshore winds and thunderstorms during the month. Close to average rainfall was recorded during December, whilst well below average rainfall was recorded in January.

There were 35 rain days over summer, which is slightly below the historical summer average of 36 rain days.

Storage levels in Sydney's catchment have risen over summer from 54.5% on 3 December to currently 59.3% of total capacity. Recent rainfall and current levels in Sydney's water catchments can be found on the Sydney Catchment Authority web site http://www.sca.nsw.gov.au/dams/rainfall.html

Temperature

Sydney experienced a record number of consecutive warm nights during summer, with 18 consecutive nights above 20.0 °C recorded over the period January 30 to February 16, exceeding the previous record of 16 consecutive nights in January/February 1973. A total of 52 nights above 20.0 °C were recorded during summer, which is well above the historical average of 21 nights. This is the second highest number of nights on record with a minimum temperature above 20 °C for summer. The current record is 64 nights set in 1990/1991.

The average minimum (overnight) temperature of 20.3 °C was 2.0 °C above the historical average 1of 18.3 °C. This is the second warmest summer on record for overnight minimum temperatures (current record is 20.7 °C, set in 1990/1991). The average maximum (daytime) temperature at Observatory Hill during summer was 26.8 °C, which is 1.2 °C above the historical average of 25.6 °C. This is the warmest summer for average maximum temperatures since 2005/2006 (27.8 °C).

Relative humidity averaged 71% at 9am, and 62% at 3pm, which is average for summer. However, Sydney experienced four consecutive days above 80% relative humidity during the period December 25th to 28th, and an exceptionally high 3pm relative humidity of 95% on the 6th February.

Some sites had their warmest summer night (highest daily minimum temperature) on record. Some sites had their highest summer mean daily minimum temperature on record.

Wind

There were 21 strong wind days reported in coastal Sydney during summer, slightly above the historical average of 19. The prevailing wind direction during summer afternoons was east/northeasterly for 62% of the time (recorded at Fort Denison).

Other phenomena

Sydney recorded a summer average of 7.3 hours of sunshine per day (recorded at Sydney Airport) which is close to the historical average of 7.1 hours per day. A total of 7 thunderstorms were reported in Sydney during summer (historical average 9), with flash flooding on the 12th and 13th.

Further information

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Extremes in summer 2009-10
Hottest day 43.3 °C at Richmond RAAF on 23 Jan 2010
Warmest days on average 30.7 °C at Penrith Lakes AWS
Coolest days on average 26.4 °C at Terrey Hills AWS
Coldest day 18.2 °C at Springwood Bowling Club on 3 Jan 2010
Coldest night 9.7 °C at Campbelltown (Mount Annan) on 3 Dec 2009
9.7 °C at Richmond RAAF on 19 Jan 2010
Coolest nights on average 17.1 °C at Campbelltown (Mount Annan)
Warmest nights on average 20.3 °C at Sydney (Observatory Hill)
20.3 °C at Sydney Airport AMO
Warmest night 26.0 °C at Sydney (Observatory Hill) on 23 Feb 2010
Wettest overall572.2 mm at Springwood Bowling Club
Wettest day 209.0 mm at Berowra (Goodwyn Road) on 7 Feb 2010
Highest wind gust 87 km/h at Sydney Airport AMO on 23 Jan 2010



Record highest summer daily minimum temperature
Highest daily minimum
temperature
in summer 2009-10 (°C)
Previous highest
for summer
Years of
record
Average for
summer
Sydney Airport AMO 25.8 on 23 Jan 2010 25.7 on 15 Jan 1978 71 18.4



Record highest summer mean daily minimum temperature
Mean daily minimum
temperature
for summer 2009-10 (°C)
Previous highest
for summer
Years of
record
Average for
summer
Parramatta North (Masons Drive) 18.4 18.2 in 1980 42 17.1



Summary statistics for summer 2009-10
Maximum temperatures
for summer
(°C)
Minimum temperatures
for summer
(°C)
Rainfall
for summer
(millimetres)
Mean for
summer
2009-10
Diff
from
average
Highest for
summer
2009-10
Mean for
summer
2009-10
Diff
from
average
Lowest for
summer
2009-10
Total for
summer
2009-10
Average
for
summer
Rank of
summer
2009-10
Fraction of
summer
average
Badgerys Creek AWS 29.9   43.0 23 Jan 2010 17.5   10.0 19 Jan 2010 208.4
Bankstown Airport AWS 28.8 +1.1 42.8 23 Jan 2010 18.7 +1.1 12.2 20 Jan 2010 169.2 267.5 low 63%
Camden Airport AWS 30.1 +1.3 43.1 17 Dec 2009 17.4 +1.2 10.1 3 Dec 2009 249.0 239.2 average 104%
Campbelltown (Mount Annan) 29.9   42.8 23 Jan 2010 17.1   9.7 3 Dec 2009 179.8
Canterbury Racecourse AWS 27.8   42.3 23 Jan 2010 18.8   11.8 20 Jan 2010 212.8
Holsworthy Control Range 29.2   42.7 23 Jan 2010 17.8   10.3 20 Jan 2010 210.8
Horsley Park Equestrian Centre AWS 29.5   42.5 23 Jan 2010 18.0   10.9 3 Dec 2009 224.2
Liverpool (Michael Wenden Centre) 29.6   42.6 23 Jan 2010 18.0   10.5 20 Jan 2010 293.0
Parramatta North (Masons Drive) 29.1 +1.2 42.3 23 Jan 2010 18.4 +1.3 12.5 20 Jan 2010 339.0 303.9 average 112%
Penrith Lakes AWS 30.7   42.9 23 Jan 2010 18.7   12.2 19 Jan 2010 349.8
Prospect Reservoir 29.7 +1.8 42.5 23 Jan 2010 18.4 +1.2 11.1 3 Dec 2009 297.0 264.2 average 112%
Richmond RAAF 30.3   43.3 23 Jan 2010 18.0   9.7 19 Jan 2010 290.6
Springwood Bowling Club 28.2   40.3 23 Jan 2010 17.3   10.1 19 Jan 2010 572.2 367.1 high 156%
Sydney (Observatory Hill) 26.8 +1.2 41.3 23 Jan 2010 20.3 +2.0 13.5 2 Dec 2009 342.2 298.1 average 115%
Sydney Airport AMO 27.5 +1.3 42.5 23 Jan 2010 20.3 +1.9 13.2 2 Dec 2009 238.8 281.7 average 85%
Sydney Olympic Park (Sydney Olympic Pk A 28.5   42.9 23 Jan 2010 19.8   13.2 2 Dec 2009 274.0
Terrey Hills AWS 26.4   40.3 23 Jan 2010 18.5   11.8 1 Dec 2009 326.0

Notes

A Seasonal Climate Summary is prepared to list the main features of the weather in Sydney - Greater Sydney using the most timely and accurate information available on the date of publication; it will generally not be updated. Later information, including data that has had greater opportunity for quality control, will be presented in the Monthly Weather Review, usually published in the fourth week of the month.

This statement has been prepared based on information available at 10 am on Monday 1 March 2010. Some checks have been made on the data, but it is possible that results will change as new information becomes available.

A note about deciles: Deciles are used to give an element (in this case rainfall or temperature) a ranking. Deciles are calculated by arranging the totals in ascending order (from lowest to highest) then splitting them into 10 equal groups (thus the groups are called deciles). The first group would be in decile range one, the second group in decile range two, etc up to the highest annual totals (highest 10 per cent) being in decile range 10.

1Averages: Averages are based on the period 1961 to 1990 which is a convention of the World Meteorological Organisation

Normals are long-term averages 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 20 years of record for temperature and less than 30 years of record for rainfall, as they cannot then be calculated reliably.

Further information

Media
(03) 9669 4057
Enquiries