Climate of Sydney

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The weather of the Sydney CBD is recorded at Observatory Hill.

The climate of Sydney is temperate, having warm, sometimes hot summers and mild winters.[1][2] Rainfall is spread evenly throughout the year, though is highest between March and June.[3] Sydney does not experience extreme seasonal differences. The weather is moderated by proximity to the ocean, and more extreme temperatures are recorded in the inland western suburbs. Summer highs average at around 25–29 °C (77–84 °F), and winter highs at 16–18 °C (61–64 °F).

Sydney gets dry heat,[4][5] though, in some days, low pressure troughs increase humidity and southerly busters (a sea breeze) decrease temperatures.[6][7] In winter, east coast lows can bring large amounts of rainfall, especially in June. Within the city and surrounds, rainfall varies, from around 682.5 mm (26.87 in) at Badgerys Creek (in the west) to 1,213.8 mm (47.79 in) at Observatory Hill (the east).

Sydney has 104 clear days annually[8][9] and gets around 30 thunderstorms per year.[9][10][11] The El Niño Southern Oscillation plays an important role in determining Sydney's weather patterns: drought and bushfire on the one hand, and storms and flooding on the other, associated with the opposite phases of the Southern Oscillation. Sydney is prone to heat waves and drought, which have become more common in recent years.[12][13][14][15]

Temperature[edit]

The highest recorded maximum temperature at Observatory Hill was 45.8 °C (114.4 °F) on 18 January 2013 during a prolonged heat wave across Australia from early December 2012 to late January 2013.[16][17] The highest recorded maximum in the Sydney metropolitan area was 47.8 °C (118.0 °F) in Richmond.[18] The lowest recorded minimum at Observatory Hill was 2.1 °C (35.8 °F) on 22 June 1932,[9] while the coldest in the Sydney metropolitan area was −8 °C (18 °F), also in Richmond.[18] The lowest recorded maximum temperature at Observatory Hill was 7.7 °C (45.9 °F) and the highest recorded minimum was 27.6 °C (81.7 °F). The average 3pm dewpoint temperature in the summer ranges from 16.2 °C (61.2 °F) at the coast, to 14.4 °C (57.9 °F) inland.[9][18]

In the Sydney central business district, an average of 14.9 days a year have temperatures of more than 30 °C (86 °F) and 3.0 days with temperatures over 35 °C (95 °F).[9] In contrast, western suburbs such as Liverpool and Penrith have 41.4 and 67.5 days of temperatures above 30 °C (86 °F), 10.2 and 19.0 days above 35 °C (95 °F), and, 1.2 and 3.9 days above 40 °C (104 °F), respectively.[19][20] In winter, lows in the Sydney CBD rarely drop below 5 °C (41 °F).[9] In the west, Liverpool and a much further inland suburb, Richmond have 4.0 and 38.8 nights, respectively, where temperatures dip below 2 °C (36 °F). On average, only 1.0 night in Liverpool and 17.7 nights in Richmond have lows going below 0 °C (32 °F).[18][19]

In the warm months, the western suburbs are significantly hotter than the Sydney CBD by 2–5 °C (4–9 °F). In extreme occasions, the coast would have a temperature of 25 °C (77 °F), while a suburb 30 km (19 mi) inland bakes in 36 °C (97 °F) heat. Maximum summer temperatures in the west average at around 28 to 30 °C (82 to 86 °F) and winter temperatures average at around 17 to 18 °C (63 to 64 °F), depending on the suburb. Winter lows are around 4 °C (7 °F) cooler inland than the coastal suburbs, which may provide mild to moderate frost in some suburbs.[21]

Heatwaves, which are regularly occurring in recent years, would usually lead to water restrictions and a high risk of bushfires, which sometimes bring a smoky haze to the city. Smog is noticeable in hot days, even without bushfires.[22] Sea temperatures average 21 °C (70 °F) and range between 19 °C (66 °F) in July and 24 °C (75 °F) in January.[23][24]

In late spring and summer, Sydney can sometimes get northwesterly winds from the Outback, which are dry and hot, making the temperatures soar above 35 °C (95 °F).[25] This happens after the northwesterlies are carried entirely over the continental landmass, not picking up additional moisture from a body of water and retaining most of their heat. On these occasions, the normally temperate parts of south eastern Australia can experience the full fury of the desert climate, although only briefly, as they are often ended with a "Southerly Buster", which is a cold front that sweeps up from the southeast abruptly cooling the temperature by bringing thunderstorms and gale winds.[26][27]


Climate data for Sydney (Observatory Hill)
Month Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Year
Record high °C (°F) 45.8
(114.4)
42.1
(107.8)
39.8
(103.6)
33.9
(93)
30.0
(86)
26.9
(80.4)
25.9
(78.6)
31.3
(88.3)
34.6
(94.3)
38.2
(100.8)
41.8
(107.2)
42.2
(108)
45.8
(114.4)
Average high °C (°F) 25.9
(78.6)
25.8
(78.4)
24.8
(76.6)
22.4
(72.3)
19.5
(67.1)
17.0
(62.6)
16.3
(61.3)
17.8
(64)
20.0
(68)
22.1
(71.8)
23.6
(74.5)
25.2
(77.4)
21.7
(71.1)
Average low °C (°F) 18.7
(65.7)
18.8
(65.8)
17.6
(63.7)
14.7
(58.5)
11.6
(52.9)
9.3
(48.7)
8.1
(46.6)
9.0
(48.2)
11.1
(52)
13.6
(56.5)
15.6
(60.1)
17.5
(63.5)
13.8
(56.8)
Record low °C (°F) 10.6
(51.1)
9.6
(49.3)
9.3
(48.7)
7.0
(44.6)
4.4
(39.9)
2.1
(35.8)
2.2
(36)
2.7
(36.9)
4.9
(40.8)
5.7
(42.3)
7.7
(45.9)
9.1
(48.4)
2.1
(35.8)
Rainfall mm (inches) 101.1
(3.98)
118.0
(4.646)
129.7
(5.106)
127.1
(5.004)
119.9
(4.72)
132.0
(5.197)
97.4
(3.835)
79.8
(3.142)
68.4
(2.693)
76.9
(3.028)
84.3
(3.319)
77.3
(3.043)
1,211.9
(47.713)
Avg. rainy days 12.2 12.5 13.6 12.8 13 12.5 11.1 10.4 10.5 11.6 11.7 11.5 143.4
 % humidity 62 64 62 59 57 57 51 49 51 56 58 59 57
Mean daily sunshine hours 7.1 6.7 6.4 6.4 5.9 5.5 6.4 7.1 7.2 7.2 7.8 7.6 6.8
Source #1: Bureau of Meteorology[9]
Source #2: [17]

Warm and cool periods[edit]

During the 2009 Australian dust storm, the city of Sydney was shrouded in dust.

The Bureau of Meteorology has reported that 2002 through 2005 were the warmest summers in Sydney since records began in 1859. 2004 saw an average daily maximum temperature of 23.4 °C (74.1 °F), 2005 of 23.4 °C (74.1 °F), 2002 of 22.9 °C (73.2 °F), and 2003 of 22.7 °C (72.9 °F). The average daily maximum between 1859 and 2004 was 21.6 °C (70.9 °F). For the first nine months of 2006 the mean temperature was 18.4 °C (65.1 °F); the warmest year previously was 2004 with 18.5 °C (65.3 °F). Since November 2003, there have been only two months in which the average daily maximum was below average: March 2005 (about 1 °C (2 °F) below average)[33] and June 2006 (0.7 °C (1.3 °F) below average).[34]

The summer of 2007–08 proved to be one of the coolest on record. The Bureau of Meteorology reported that it was the coolest summer in 11 years, the wettest summer in six years, and one of only three summers in recorded history to lack a maximum temperature above 31 °C (88 °F).[35]

The Bureau of Meteorology reported that 2009 was a warm year, with above-average maximum temperatures. In 2009, the average annual daytime temperature at Observatory Hill was 22.9 °C (73.2 °F), which is 0.9 °C (1.6 °F) above the historical annual average. This ranks as seventh highest annual average maximum temperature since records commenced in 1859. It was the seventeenth consecutive year with above average annual maximum temperatures. Average night-time temperatures at Sydney Observatory Hill of 15.1 °C (59.2 °F) were well above (1.2 °C (2.2 °F)) the historical average during 2009. This is equal second highest in the 151 years of record, and the same as 1988.[36]

The year 2010 was a warm, wetter year with an average maximum of 22.6 °C (72.7 °F), which was 0.6 °C (1.1 °F) above the historical annual average. Night-time temperatures were also above average, at 15.0 °C (59.0 °F) during this year, compared to a historical average of 13.9 °C (57.0 °F). 2010 was the equal fourth warmest year on record for Sydney. Seven (of the ten) warmest years on 151 years of record have occurred in the ten years between 2001 and 2010, with this decade being the warmest on record for minimum temperatures.[37]

Towards the end of January 2011 the city had a heat wave that brought up the temperatures to over 30 °C (86 °F) for five consecutive days. The west had five days with temperatures over 35 °C (95 °F).[38] February 2011 was the second warmest on record for mean temperatures and third warmest for maxima.

In 2013, the city had the warmest July and September on record,[39][40] with September being one of the driest with the temperatures being 4 °C (7 °F) above average.[41] The city had over seven days with temperatures reaching 28 °C (82 °F), making it more similar to November's weather pattern.[42] October was also a warmer than average month where the temperature peaked at 37 °C (99 °F), making it the third hottest October day.[43] Sydney's summer of 2013-14 did not record any temperatures above 37 °C (99 °F) for the first time in two years, with January being cooler than the previous September and October.[44]

Precipitation[edit]

Rainfall is fairly evenly spread through the year, with wetter areas being closer to the coast or in higher altitudes. Precipitation is slightly higher during the first half of the year when easterly winds dominate (February–June), and lower in the second half (mainly July–September).[45][46] The average annual rainfall at Observatory Hill, with moderate to low variability, is 1,213.8 mm (47.79 in), falling on an average 143.5 days a year. As seen from the climate table above, Sydney's wettest month is June,[9] though most of its western suburbs' wettest month is February or March.[19][20]

In the warm months, rain comes in heavy downpours, mainly in the afternoons, where it would usually give away to the sun. In the cool months rain may come in drizzle form and would linger on for the whole day.[47] Most suburbs in the west have an annual rainfall that averages between 700 to 900 mm (28 to 35 in) with around 100 to 115 annual rain days. Even in its months of highest rainfall Sydney has relatively few rainy days, on average less than 14 rainy days per month.[9][19][20] This means the average rain event in Sydney contains heavy rain.

The city is not affected by cyclones, although remnants of ex-cyclones do affect the city.[48] The city is prone to severe hail storms, such as the 1947 Sydney hailstorm, wind storms, and flash flooding from rain caused either by east coast lows (during autumn-winter periods) and ex-tropical cyclone remnants (during spring-summer periods). They are low pressure depressions that can bring significant damage by heavy rain, cyclonic winds and huge swells. Scientists have predicted that rainfall will become more unpredictable and temperatures will be on the rise.[49] Averaging at 332km/h, November is the windiest month, whilst March is the calmest at 272km/h.[9]

Snowfall was last reported in the Sydney area in 1836. T. A. Browne, who kept weather observations, noted that "the years 1836, 1837 and 1838 were years of drought, and in one of these years (1836) a remarkable thing happened. There was a fall of snow; we made snowballs at Enmore and enjoyed the usual schoolboy amusements therewith". The Sydney Herald reported on the same incident, saying, "for the first time in the memory of the oldest inhabitants, snow fell in Sydney on the morning of Tuesday last. 27 June 1836, about 7 o'clock in the morning, a drifting fall covered the streets nearly one inch in depth."[50] A July 2008 fall of graupel, or soft hail, mistaken by many for snow, has raised the possibility that the 1836 event was not snow.[51]

Notable events[edit]

A boat at Rose Bay during the 1947 Sydney hailstorm

A notable event was the great Sydney flood which occurred on 6 August 1986 (unusual in that month) and dumped a record 327.6 mm (12.90 in) on the city in 24 hours. This caused major traffic problems and damage in many parts of the metropolitan area.[52] The next notable event was the 1999 hailstorm, which severely damaged Sydney's eastern and city suburbs. The storm produced massive hailstones of at least 9 cm (3.5 in) in diameter and resulting in insurance losses of around A$1.7 billion in less than five hours.[53]

In the first weeks of February 2010, Sydney received some of the highest rainfalls in 25 years, which caused flash flooding and traffic chaos. On 4 February, some suburbs in the North Shore region recorded their heaviest rain in 20 years. On 12 and 13 February, some suburbs were hit by thunderstorms which brought heavy rain and gusty winds which cut out power and damaged homes.[54][55] On 13 February, Sydney experienced one of the highest rainfall of the last decade with 65 mm (2.6 in) of rain falling in one night at Observatory Hill.[56] The heavy rain was caused by remnants of ex-tropical Cyclone Olga and humid north-easterly winds feeding into the low pressure trough.[57][58] 2010 was the wettest year since 2007, according to the Bureau of Meteorology, with the cloudiest October and the third cloudiest July on record.

March and April 2011 were very wet with well above average rainfall. March recorded 191.6 mm (7.54 in) well above the average of 128.9 mm (5.07 in) of rain and was the wettest March in ten years. April 2011 recorded 206.2 mm (8.12 in) of rain well above the average of 125.8 mm (4.95 in) and was the wettest April since 1999. May 2011 also recorded above average rainfall, making it the wettest autumn since 2003 according to the Bureau.[59][60] July 2011 was the wettest July since 1950.[61]

In November 2013, a tornado hit Hornsby, a suburb in the Upper North Shore. The tornado's path was 2 km (1.2 mi) long and 50 m (160 ft) wide. The tornado blew off roofs, partially collapsed a cinema roof, and toppled large trees. The winds in the tornado reached 140 km an hour.[62][63]

Drought[edit]

Smoke from bushfires around Sydney, January 1994

Sydney's climate appears to be becoming drier; The city has had fewer rain days in recent years than shown in the long-term climate table above. In summer, Sydney can go for long periods without rainfall. The other phenomenon that arises from these long, dry and hot periods is bushfires, which occur frequently in the areas surrounding the city. Water supply is a recurring concern for the city during drought periods.

In 2005 the reservoirs reached an all-time low. However, water levels since then have recovered in 2013. The years 2009 and 2010 had dry conditions, according to Bureau of Meteorology.[64] In 2011, Sydney had the driest February in 30 years with only 18 mm (0.71 in) of rain falling, which is well below than the average 118 mm (4.6 in). Some of the western suburbs recorded the lowest total February rainfall on record.[65]

In September 2013, the combination of dry weather, warm temperatures and strong winds brought early-season bushfires. Major bushfires impacted western Sydney and the Blue Mountains, resulting in some evacuations, closed roads, and destroyed homes.[40]

Many areas of the city bordering bushland have experienced bushfires, notably in 1994 and 2001–02 — these tend to occur during the spring and summer.

Dust storms[edit]

On 23 September 2009, a dust storm that started in South Australia and inland New South Wales blanketed the city with reddish orange skies.[66] It stretched as far north as southern Queensland and it was the worst dust storm in 70 years.[67] During that year, Sydney experienced a number of warm winter days, dry gusty winds and another milder dust storm.[68][69]

Aboriginal seasons[edit]

The Sydney basin was in the Tharawal country. Each clan had knowledge of their area and the season changes. These were the seasons of the Sydney region according to the Aboriginal people living there: [70]

  • January/February/March (Burran) - Hot and dry
  • April/May/June (Marrai'gang) - Wet, becoming cooler
  • June/July (Burrugin) - Cold, frosty, short days
  • August (Wiritjiribin) - Cold and windy
  • September/October (Ngoonungi) - Cool, getting warmer
  • November/December (Parra'dowee) - Warm and wet

See also[edit]

References[edit]

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  2. ^ "Australian climatic zones". Australian Government. Bureau of Meteorology. Archived from the original on 5 July 2008. Retrieved 21 December 2008. 
  3. ^ "Climate and the Sydney 2000 Olympic Games". Australian Government. Australian Bureau of Statistics. 24 September 2007. Retrieved 21 December 2008. 
  4. ^ "Hot Enough? Things are going to get hotter". The Sydney Morning Herald. 2014. Retrieved October 30, 2014. 
  5. ^ "Sydney heatwave". Daily Liberal. 2013. Retrieved 4 February 2014. 
  6. ^ "Sea Breezes on the NSW Coast". BOM. Ken Batt. Retrieved 12 November 2014. 
  7. ^ Batt, K, 1995: Sea breezes on the NSW coast, Offshore Yachting, Oct/Nov 1995, Jamieson Publishing.
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  20. ^ a b c d "Penrith". Climate statistics for Australian locations. Bureau of Meteorology. Retrieved 15 November 2014. 
  21. ^ Sydney’s Climate
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  25. ^ Heatwave blows in on a fiery desert wind
  26. ^ Sydney Weather
  27. ^ Southerly buster
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  35. ^ Sydney has coolest summer in 11 years in Sydney Climate Summary — NSW Regional Office, Bureau of Meteorology. Retrieved 25 March 2008.
  36. ^ Year 2009: Very warm with below average rainfall in Sydney
  37. ^ Sydney in 2010: 18th consecutive warm year
  38. ^ Special Climate Statement 27 - An exceptional summer heatwave in greater Sydney and the Hunter Valley.
  39. ^ Sydney in July 2013: Warmest July on record
  40. ^ a b Sydney in September 2013: Warmest September on record
  41. ^ Climate Council reports warmest September on record
  42. ^ September’s average temperature for Sydney beats 33-year-old record
  43. ^ Sydney gets its third hottest October day
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  45. ^ Climate of Sydney Australia the Good and the Bad
  46. ^ Australia > New South Wales > Sydney
  47. ^ "The Lost Seasons". 
  48. ^ Tropical Cyclones in New South Wales
  49. ^ {{cite news|url=http://www.sydneywater.com.au/SW/teachers-students/facts-about-water/secondary-students/the-water-cycle-in-nature/weather---climate/index.htm<|title=Weather & climate|accessdate=25 December 2014
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  59. ^ Sydney in April 2011: Wettest April since 1999
  60. ^ Sydney in May 2011: Coldest nights in 40 years
  61. ^ Sydney's wettest July since 1950
  62. ^ Clean-up continues after tornado strikes at Hornsby in Sydney's north
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  65. ^ Sydney in January 2011: Warm start to 2011
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  67. ^ Brisbane on alert as dust storms sweep east
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External links[edit]