Sydney in May 2011: Coldest nights in 40 years

  • Above average rainfall
  • Wettest May day since 2003
  • Coldest minimum temperatures since 1970
  • Coldest maximum temperatures since 1979

Rainfall

Sydney Observatory Hill recorded 135.6 mm of rainfall during May 2011, slightly above the historical average of 121.2 mm although drier than May 2010. The majority of the rain fell during the last two days of the month, as a coastal low pressure trough with an upper low in northern NSW caused a two-day total of 101.2 mm at Observatory Hill. Rain was particularly heavy on the 31st, reaching 65.2 mm at Observatory Hill, the wettest May day since 2003, and 103.4 mm at Parramatta North. This event was associated with flash flooding in Sydney on the 30th, particularly in southern suburbs near the Airport.

The remainder of the month was fairly dry, associated with generally cool, dry southwesterly winds. Only 11 rain days were observed at Observatory Hill during the month, below the May average of 13 rain days, the majority of which recorded less than 5 mm. The only other significant rain event occurred between the 25th and 26th, with two-day totals of 21.4 mm at Observatory Hill and up to 50 mm at Rose Bay and Dover Heights. This event was associated with an East Coast Low off the NSW coast, which are typical for late autumn and winter in Sydney.

Temperature

Sydney Observatory Hill recorded slightly above average maximum temperatures during May, averaging 19.5 °C compared to the historical average of 19.4 °C, although significantly below the 1961-1990 average of 20.3 °C. This is the coolest May for maximum temperatures since 18.9 °C was recorded in May 1979, reflecting more than thirty consecutive years of above average maximum temperatures. In comparison, most of the Metropolitan area had average maximum temperatures close to 1 °C below their historical average, based on records generally beginning in the 1960s.

Minimum temperatures were colder during May, with an average minimum temperature at Observatory Hill of 10.7 °C compared to the historical average of 11.5 °C. This is the lowest minimum temperature since 10.4 °C was recorded in May 1970. Interestingly, average minimum temperatures less than or equal to 10.7 °C were recorded 19 times at Observatory Hill between 1910 and 1970, with such temperatures typical of the early part of the 20th century. In comparison, the majority of stations in western Sydney had temperatures close to 2 °C below the historical average, including the coldest May on record at Prospect Reservoir.

Some sites had their lowest May mean daily minimum temperature on record.

Wind

The average wind direction at Sydney Airport during May was westerly to southwesterly, with more than 90% of 9am winds between NW and SW, and 55% of 3pm winds between S and W. This was a larger proportion than typical for May, with the southwesterly winds driving cool conditions during the month.

Eight strong wind days were reported at Sydney Airport, well above average for May and the highest frequency since 9 strong wind days were reported in May 1972. The windiest days were the 25th, when an East Coast Low caused wind gusts of up to 91 km/hr at Port Botany, and on the 30th as a strong low pressure trough and upper level low caused wind gusts of up to 94 km/hr at Fort Denison.

Other phenomena

Sydney Airport averaged 6.8 hours of sunshine during May, above the historical average of 6.1 hours. No thunderstorms were reported at the Airport, below average for May, with five storms reported in the Metropolitan region during the month.

Further information

Media
(03) 9669 4057
Enquiries

Extremes in May 2011
Hottest day 25.0 °C at Sydney Olympic Park (Sydney Olympic Pk A on the 21st
Warmest days on average 19.9 °C at Liverpool (Michael Wenden Centre)
Coolest days on average 17.6 °C at Springwood (Valley Heights)
Coldest day 12.5 °C at Terrey Hills AWS on the 25th
Coldest night -1.4 °C at Richmond RAAF on the 16th
Coolest nights on average 5.1 °C at Camden Airport AWS
Warmest nights on average 10.7 °C at Sydney (Observatory Hill)
Warmest night 15.2 °C at Sydney Airport AMO on the 1st
Warmest on average overall 15.1 °C at Sydney (Observatory Hill)
Coolest on average overall 12.3 °C at Camden Airport AWS
Wettest overall 147.8 mm at Rose Bay (Royal Sydney Golf Club)
Wettest day 103.4 mm at Parramatta North (Masons Drive) on the 31st
Highest wind gust 94 km/h at Fort Denison on the 30th


Record lowest May mean daily minimum temperature
Mean daily minimum
temperature
for May 2011 (°C)
Previous coolest
for May
Years of
record
Average for
May
Prospect Reservoir 8.1 = 8.1 in 2008 45 10.0


Summary statistics for May 2011
Maximum temperatures
for May
(°C)
Minimum temperatures
for May
(°C)
Rainfall
for May
(millimetres)
Mean for
May
2011
Diff
from
average
Highest for
May
2011
Mean for
May
2011
Diff
from
average
Lowest for
May
2011
Total for
May
2011
Average
for
May
Rank of
May
2011
Fraction of
May
average
Badgerys Creek AWS 19.7   24.1 21st 6.2   -0.1 16th 52.2
Bankstown Airport AWS 19.4 -1.0 23.9 21st 8.0 -1.6 2.5 11th 82.8 71.1 average 116%
Camden Airport AWS 19.6 -1.0 24.3 21st 5.1 -2.1 -1.3 16th 49.0 58.6 average 84%
Campbelltown (Mount Annan) 19.7   24.6 21st 6.1   -0.2 11th 54.8
Canterbury Racecourse AWS 19.3   23.6 21st 7.9   2.0 11th 62.2
Holsworthy Control Range 19.3   23.7 21st 7.4   -0.1 11th 69.4
Horsley Park Equestrian Centre AWS 19.2   23.5 21st 7.6   1.6 16th 14.0
Liverpool (Michael Wenden Centre) 19.9   24.2 21st 6.9   1.2 11th 69.7
Parramatta North (Masons Drive) 19.4 -1.1 24.5 21st 8.4 -1.6 3.8 15th 131.8 73.5 high 179%
Penrith Lakes AWS 19.7   23.2 21st 7.8   2.6 12th 40.8
Prospect Reservoir 19.0 -1.3 23.0 21st 8.1 -1.9 2.7 15th 62.4 72.0 average 87%
Richmond RAAF 19.3   23.8 21st 5.8   -1.4 16th 50.2
Riverview Observatory 18.9 -0.7 23.4 23rd 8.7 -1.2 5.1 11th 69.3 106.3 average 65%
Springwood (Valley Heights) 17.6   21.0 23rd 8.4   3.5 16th 45.6 73.7 average 62%
Sydney (Observatory Hill) 19.5 +0.1 23.3 21st 10.7 -0.8 7.3 15th 135.6 121.2 high 112%
Sydney Airport AMO 19.1 -0.9 24.2 23rd 10.5 -0.4 6.6 15th 91.8 100.9 average 91%
Sydney Olympic Park (Sydney Olympic Pk A 19.8   25.0 21st 9.8   5.7 11th
Terrey Hills AWS 17.8   22.6 21st 9.0   4.7 12th 27.6

Daily rainfall
Hunter (61)12345678910111213141516171819202122232425262728293031
Webbs Ck-Wisemans Ferry (Hawkesbury Rive 0.5 - - - - - - - - - - - - - - - - - 0.5 - - - - 0.5 2.0 - - - - 3.0 38.5
Central Tablelands (South) (63)12345678910111213141516171819202122232425262728293031
Sackville Ferry (Hawkesbury River) 2.6 0.2 - 0.2 0.2 - 0.2 0.2 - 0.2 - - - - - 0.2 - 0.2 0.2 0.2 0.2 0.2 2.0 - 2.2 - - 0.2 - 4.2 44.6
Springwood (Valley Heights) 1.8 - 0.6 0.6 - - - - - - - - - - - - - - - - - - 2.0 - 7.2 - - - - 1.4 32.0
Valley Heights (Sun Valley Rd) 2.2 - 0.6 0.6 - -
- - - - - - - -
- - - -
- 2.4 - 7.2 - - - - 15.2 33.0
Metropolitan (East) (66)12345678910111213141516171819202122232425262728293031
Abbotsford (Blackwall Point Rd) 5.0
1.0


















2.0
3.2 2.2


19.0 96.0
Auburn (Rosnay Golf Club) 3.0 1.0 - - - - - - - - - - - - 1.0 - - - - - - - 1.0 - 4.0 - - - - 19.0 53.0
Audley (Royal National Park) 23.0 - 1.0 - - - - - - 2.0 - - - - - - - - - 1.0 - - - - 6.0 7.0 - - - 23.0 70.0
Avalon (Wollstonecraft Ave) 3.0 - - - - - - - - 18.0 - - - - - - - - 4.0 - - - 1.0 - 16.0 10.0 - - - 57.0 23.0
Avalon Beach (Avalon (Palmgrove Rd))








18.8







5.0


2.0
15.2 12.2


49.0 34.2
Bankstown Airport AWS 6.4 - 0.4 - - -
- - - - - - - - - - - - - - - 1.0 - 1.4 - - - - 13.6 60.0
Belrose (Evelyn Place) 1.0
5.4





2.0


0.4



3.2


1.8
10.4 6.0


26.8 52.2
Campbelltown (Ingleburn (Long Point)) 12.0 - - - - - - - - - - - - - - - - - - - - - 3.0 - - - - - - 12.0 61.0
Canterbury Racecourse AWS 5.8 - 0.4 - - - - - - - - - - - - - - - - - - - - - - - - - - - 56.0
Castle Cove (Rosebridge Ave) 1.5
2.0





4.0


0.5



1.2


1.2
9.0 10.0


22.0 81.0
Chatswood Bowling Club 3.0 - 2.0 - - - - - - 1.0 - - - - - - - - 2.0 1.0 - - 1.0 - 4.0 5.0 - - - 28.0 47.0
Collaroy (Long Reef Golf Club)








14.4







4.0


1.4

10.2


50.2 27.8
Concord Golf Club 5.6
1.6














1.2


2.0
4.8 0.8


25.4 73.4
Cronulla South Bowling Club »» 13.6

1.2



10.8











0.8
23.0 17.0




Guildford (Woodville Golf Club) 14.0 - 1.0 - - - - - - - - - - - - - - - - - - - 1.0 - 4.0 - - - - 22.0 51.0
Holsworthy Control Range 7.0 - 0.4 - - - - - - - - - - - - - - - - - - - 1.6 - 0.2 - - - - 8.2 52.0
Lidcombe (Carnarvon Golf Club) 4.0 - - - - - - - - - - - - 1.0 - - - - - - - - 1.0 - 3.0 - - - - 13.0 40.0
Liverpool-Scrivener St (Georges River) 6.0 - - - - - - - - - - - - - - - - - - - - - 1.0 - 1.0 - - - - 8.0 55.0
Lucas Heights (ANSTO) 21.3
0.3









3.0







1.2
4.8 0.6


10.4 73.0
Macquarie Park (Willandra Village) 4.8







0.6


0.6



2.0


1.8
3.6



20.6 56.0
Manley / Warringah (Allambie) - - 3.0 0.5 - - - - - 2.5 - - - - -
- - 8.5 - - - 1.0 - 9.5 8.0 0.5 - - 24.0 41.0
Manley / Warringah (Belrose)
- 3.5
- - - - - 1.5 - - - - - - -

- - - 1.0
7.0
- - - 24.5 47.5
Marrickville Golf Club 7.0 1.0 - - - - - - - 1.0 - - - - - - - - 2.0 1.0 - - 1.0 - 5.0 5.0 - - - 33.0 56.0
Milperra Bridge (Georges River)





- - - - - - - - - - - - - - - - - - - - - - - 8.0 59.0
Mona Vale Golf Club 3.8 0.2 0.8 - - - - 0.2 - 13.0 - - - - - - 0.2 - 2.2 0.4 0.6 0.2 2.0 - 12.6 9.6 - - - 43.0 26.2
Parramatta (Erts) 6.0 - - - - - - - - - - - - - - - - - - - - - 0.5 - 1.5 - - - - 10.5 45.0
Parramatta North (Masons Drive) 6.8 0.2 0.8 - - - - - - 0.2 - - - - - - - - - - - - 1.6 - 3.6 0.2 - - - 15.0 103
Peakhurst Golf Club 12.0 1.0 - - - - - - - - - - - - - - - - - - - - 1.0 - 5.0 1.0 - - - 17.0 52.0
Randwick Bowling Club 1.6
1.4 0.2




9.6







2.4


1.0
19.0 21.2


27.6 60.6
Riverview Observatory 5.0 - 1.2 - 0.2 - - - - 0.6 - - - 0.4 - - - - »» 0.2 0.2 - - - 4.2 2.9 0.2 - - 19.1 29.7
Rose Bay (Royal Sydney Golf Club) 4.4
9.4 1.0



0.4 6.4







1.6


1.0
21.8 28.8


20.6 52.4
Sans Souci (Public School) 21.0 - - - - - - - - 5.0 - - - - - - - - - - - - 1.0 - 9.0 8.0 - - - 21.0 47.0
St Ives (Richmond Avenue) 5.2

1.0




2.6







4.4


1.6
6.0 4.4


20.4 64.4
Strathfield Golf Club 2.0 1.0 - - - - - - - - 1.0 - - - - - - - - 1.0 - - 1.0 - 4.0 - - - - 25.0 56.0
Sydney (Observatory Hill) 3.6 - 0.6 0.4 0.2 - - - - 4.4 0.2 - - - - - - - 2.6 - - - 1.0 - 12.0 9.4 - - - 36.0 65.2
Sydney Airport AMO 0.8 - 0.2 0.2 0.2 - - - - 3.6 - - - - - - - - 1.0 - - - 0.8 - 8.8 9.2 - - - 21.6 45.4
Sydney Olympic Park (Sydney Olympic Pk A 4.4 - 0.4 - - - - - - 0.4 0.4 0.2 - 0.4 0.2 0.4 - - - - - - 1.4
3.8 - - - - 26.0 64.8
Terrey Hills AWS 0.8 0.2 1.6 - - - - - -
- - - - - - - - 7.2 - - - 1.4 - 11.2 5.2 - - -

Turramurra (Kissing Point Road) 3.0
0.6 0.2




0.6


0.2



1.6


1.8
5.0 2.0


25.0 62.0
West Pymble (Wyuna Road) 4.8 0.2 2.0 - - - - - - 0.6













»» »» »» »» »» »» 93.0
Metropolitan (West) (67)12345678910111213141516171819202122232425262728293031
Abbotsbury (Fairfield City Farm) 6.0 - - - - - - - - - - - - - - - - - - - - - 2.0 - 1.0 - - - - 8.0 54.0
Badgerys Creek AWS 8.2 - 0.2 - 0.2 - - - - - - - - 0.2 - - - - - - - - 3.0 - 1.2 - - - - 4.4 34.8
Baulkham Hills (Swimming Pool ) 6.5 - 1.0 - - - - - - - - - - - - - - - - - - - 1.5 - 2.5 - - - - 12.0 73.0
Baulkham Hills Eucalyptus Ct 5.0 - 0.5 - - - - - - - - - - - - - - - - - - - 1.0 0.5 4.5 - - - - 14.0 90.0
Berowra (Goodwyn Road)

0.6


















1.6
»» 5.0


13.0 46.2
Blacktown (Dog Pound) 1.0 - 0.5 - - - - - - - - - - - - - - - - - - - 2.0 - 0.5 - - - - 9.5 43.5
Box Hill (Hynds Road) 2.0 - 1.0 - - - - 1.0 - - - - - - - - - - - - - - 3.0 - 3.0 - - - - 6.0 49.0
Castle Hill (Kathleen Ave) 8.0 0.2 0.8 0.2














0.2

2.2
2.8 0.1

0.1 13.0 66.6
Glenorie (Old Northern Rd) 7.2

















1.2

4.4
2.6



8.0 50.0
Greystanes (Cumberland Golf Club) 2.0 - - - - - - - - - - - - - - - - - - - - - 1.0 - 1.0 - - - - 13.5 52.0
Hawkesbury River (Sackville Downstream) 2.0 - - - - - - - - - - - - - - - -
- - - - - - 1.5 - - - - 1.0 35.0
Horsley Park Equestrian Centre AWS 3.4 0.2 0.2 - - - - - -
- - - - - - - - - - 0.2 - 2.0 - 0.6 - 0.2 - - 7.2
Kelso Ck (Kelso Creek U/S Levee (Georges 6.0 - - 0.5 - - - - - - - - - - - - - - - - - - 1.5 - 0.5 - - 0.5 - 10.0 49.5
Kings Langley (NSW Soccer Federation) 4.0 0.5 - - - - - - - - - - - - - - - - - - - - 2.0 - 0.5 - - 0.5 - 12.0 86.0
Kings Langley (Solander Rd) 6.4 - 0.2 - - - - - - - - - - - - - - - - 0.2 - - 1.8 - 0.6 -
- - 12.8 82.0
Liverpool (Michael Wenden Centre) 4.3 »» 0.4 - - - - - - - - - - 0.2 - - - - - - - - - - 2.0 0.2 - - - 8.4 54.2
Lower Portland (Hawkesbury River) 4.0 0.2 - - 0.2 - - - - - - - - - - - - - - - - - 2.2 - 2.6 - - - - 3.8 30.6
Maroota (Tobruk) 9.8 0.4 0.2 - - - - 0.2 - - - - - - - - - - - 0.4 - - 2.8 - 3.0 - - - - 4.4 40.8
Merrylands (Welsford Street) 4.4




















2.4





5.6 55.2
Merrylands West (Finlayson Creek) 4.0 - - - - - - - - - - - - - - - - - - - - - 2.0 - 1.0 - - - - 21.0 80.5
North Parramatta (Burnside Homes) 6.0 - 0.5 - - - - - - - - - - 0.5 - - - - - - - - 1.0 0.5 3.0 - - - - 13.5 99.0
North Rocks (Muirfield Golf Club) 20.5 - 0.5 1.5 - - - - - - - - - - - - - - - - - - 1.5 0.5 1.5 - - - - 17.0 92.5
Northmead Bowling Club 7.0 - 0.5 - - - - - - - - - - - - - - - - - - - 1.5 - 1.0 - - - - 12.5 96.0
Parramatta (Baulkham Hills West (Sierra 3.0 - - - - - - - - - - - - - - - - - - - - - 1.5 - 0.5 - - - - 12.0 86.0
Penrith Lakes AWS 2.4 - 0.2 0.2 - 0.2 - 0.2 - 0.2 - - - 0.2 - - 0.2 - 0.2 - 0.2 - 2.0 - 3.6 - - 0.2 - 3.4 27.4
Prospect Reservoir 2.0 - - - - - - - - - - - - - - - - - - - - - 1.7 - 1.0 - - - - 9.9 47.8
Richmond RAAF 2.4 0.2 0.8 - - - - - - - - - - - - - - - - - 0.2 - 1.6 0.2 3.6 - 0.2 - - 6.6 34.4
Seven Hills (Radio FM 103.2) 2.0 - - - - - - - - - - - - - - - - - - - - - 1.5 - 0.5 - - - - 12.0 41.5
Seven Hills (Collins St) 3.2




















2.0





3.2 71.5
South Creek (Elizabeth Drive) 1.0 - - 0.1 - - - - - - - - - - - - - - - - - - 0.2 - 0.2 - - - - 0.4 4.3
St Clair (Juba Close) 3.0 - - - - - 1.0 - - - - - - - - - - - - - - - 1.0 - 3.0 - - - 1.0 3.0 27.0
Toongabbie Bowling Club 2.5 - - - - - - - - - - - - - - - - - - - - - 1.0 0.5 0.5 - - - - 13.0 63.0
Toongabbie Ck (Redbank Road (Toongabbee 6.0 - - - - - - - - - - - - - - - - - - - - - 1.5 - 2.0 - - - - 14.5 71.0
West Pennant Hills (Cumberland S F Alert 13.0 - 1.0 - - - - - - - - - - - - - - - - 0.5 - - 1.5 0.5 1.5 - - 0.5 - 14.5 55.5
Willmot (Resolution Ave) 2.0 - - - - - - - - - - - - - - - - - - - - - 1.0 - 3.0 - - - - 4.0 33.0
Windsor SWC (Hawkesbury River) 2.0 1.0 - - - - - - - 2.0 - - - - - - - - - - - - - - - 1.0 - - - - 7.0
Illawarra (68)12345678910111213141516171819202122232425262728293031
Camden Airport AWS 0.4 0.2 1.0 0.4 - - - 0.2 - - - - - 0.2 - - 0.2 - - 0.2 - - 3.4 - 3.8 - - - - 7.2 31.8
Camden Valley Golf Resort 3.0 - - - - - - - - - - - - - - - - - - - - - 3.0 - - - - - - 8.0 25.0
Campbelltown (Kentlyn (Georges River Roa 8.0 - 1.0 - - - - - - - - - - 1.0 - - - - - - - - 2.0 - 1.0 - - - - - -
Campbelltown (Mount Annan) 2.2 - 0.4 0.2 - - - - - - - - - 0.4 - - - - - - - - 3.2 - 1.0 - - - - 7.6 39.8
Rossmore (South Creek) 6.0 - - 1.0 - - - - - - - - - - - - - - - - - - 2.0 - 1.0 - - - - 7.0 41.0

Most values are the precipitation in the 24 hours to 9 am on the day indicated. Days marked with »» are part of a longer accumulation, which is marked like this on the final day. Values over 100 mm have been rounded to the nearest whole millimetre. Days marked with - have a rainfall report of zero; days left blank have no rainfall report (which often indicates no rain fell).
This table is very wide; you may have to scroll sideways to see all the days, and you may need to set the paper to 'landscape' to print.


Notes

A Monthly 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 Wednesday 1 June 2011. Some checks have been made on the data, but it is possible that results will change as new information becomes available.

Averages 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 20 years of record, as they cannot then be calculated reliably.
The median is sometimes more representative than the mean of long-term average 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, average in decile 4 to 7, high in decile 8 or 9 and very high is in decile 10).
The Fraction of average shows how much rain has fallen this time as a percentage of the long-term mean.

Further information

Media
(03) 9669 4057
Enquiries