Monday 2 July 2007 - Monthly Climate Summary for Sydney extremes - Product code IDCKGC1xx0

Sydney has wettest June for 57 years


  • Wettest June since 1950 and second wettest June on record
  • Wettest month since February 1990
  • This June ranks as 10th wettest for any month in 149 years of record
  • Cold days, average maximum temperature of 16.8°C lowest since 1989
  • Cloudy month: sunshine averaged 4.7 hours per day, lowest since 1998
  • Windy month: 3 gales, highest for June since 1975, and 7 strong wind days


The total June rainfall of 510.6 mm at Sydney Observatory Hill was very much above the historic June average1 of 128.1 mm and the 2nd wettest June since records commenced in 1859.  The wettest was 642.7 mm in 1950 (the highest for any month in Sydney).  This June was the wettest month in Sydney since February 1990 (when 630.6 mm was recorded).  In the 14 days from 7th to 20th, 466 mm was recorded at Observatory Hill, the wettest fortnight for 17 years and the 10th wettest fortnight in 149 years of record.  There were 16 rain days during the month, well above the historic average of 11 rain days and the highest for June since 1989 (when 17 days). Rainfall totals for June were heaviest in eastern and northern suburbs and lowest in the far south-west. Metropolitan rainfall ranged from 510.6 mm at Sydney Observatory Hill to 209 mm at Camden Valley in the far south-west.

Much of the rain was caused by 5 systems known as "east coast lows" that affected Sydney during June. (Further information about east coast lows can be found at: ).  The NSW coast would normally expect significant impacts from about 1 or 2 east coast lows per year, and although the number of occurrences is highly variable from year to year, 5 in one month is rare. The high number in June was due to the persistence of conditions that were particularly favourable for their development, including:   persistent strong high pressure systems south of the Bight which directed several bursts of cold air over NSW during the month leading to cooler surface temperatures and instability in the upper atmosphere; and above average sea surface temperatures in the Tasman Sea which provided high levels of moisture and also combined with the cooler land temperatures to create a strongly enhanced temperature gradient along the coast. In addition, east coast lows and the conditions that favour their development are more common during transition periods between the drier El Niņo events and wetter La Niņa periods. Although we have not yet reached the formal threshold for a La Niņa many global climate computer models are forecasting a La Niņa to develop in the next few months.

The Warragamba Dam catchment area received heavy rainfall during June, raising storage levels significantly. Total June rainfalls of 200 - 300 mm were recorded in the lower catchment with up to 393 mm at Katoomba on the catchment divide.  Even the upper catchment recorded monthly totals of nearly 200 mm in the Goulburn area.  Recent rainfall in Sydney's catchments can be found on the Sydney Catchment Authority web site at:


The average maximum (daytime) temperature at Observatory Hill was 16.8°C, or 0.9°C below the historic average1of 17.7°C. This is the coldest average maximum for June since 1989 (when 16.7°C). The western suburbs recorded slightly cooler daytime temperatures. Springwood (elevation 362 metres) recording maximum temperatures more than 2°C lower than on the coast. Both Bankstown and Camden recorded their lowest average maximum temperatures on record for June.

Nights were also cool along the coast with slightly below average minimum temperatures. The average minimum at Sydney (Observatory Hill) of 9.4°C was 0.2°C below the historic June average.1 However slightly above average minimum temperatures were recorded in most suburbs away from the coast.

The cold conditions during June were in part due to several bursts of cold southerly air over Sydney during the month combined with greater than average cloudiness and rain.

The highest temperature at Sydney (Observatory Hill) during June was 20.7°C on the 2nd while the lowest temperature was 4.9°C on the 23rd.  Corresponding extremes in the Sydney area ranged from 21.0°C at Sydney Olympic Park on the 2nd to −2.0°C at Richmond on the 23rd.

Some sites had their lowest June mean daily maximum temperature on record.


Associated particularly with the east coast low events, Sydney experienced windy conditions in June. Winds were strongest along the coast, with the prevailing direction between W and S.  There were 3 days of gales (average speed 63 km/hr or more), the highest number in June since 1975.  Normally Sydney would expect 1 gale every 3 years in June. There were also 7 strong wind days (average speed 40−62 km/hr) which is well above the historic average of 4 strong wind days.  The highest wind gust in the Sydney area during June was 106 km/hr at Fort Denison on the 8th.

Other phenomena

Generally cloudy conditions persisted during June with sunshine averaging only 4.7 hours per day, the lowest since 1998. The historic average for June is 6.1 hours per day. There were two thunderstorms during the month (historic average 1storm). There was local flooding in and around Sydney on the 9th and 16th. Strong winds caused considerable damage in coastal suburbs, bringing down trees and power lines and blowing beach sand a hundred metres inland.  Huge seas and a heavy SE swell generated by the east coast lows caused severe erosion along several Sydney beaches with wave heights up to 14 metres recorded off Sydney on 9 June.

Further information

Mike De Salis
NSW Climate Services Centre
Bureau of Meteorology
Phone (02) 9296 1555

Extremes for the Sydney area

Hottest day
Highest temperature
21.0°C at Sydney Olympic Park on the 2nd
Warmest days on average
Highest mean daily maximum temperature
16.8°C at Liverpool, Sydney (Observatory Hill) and Sydney Olympic Park
Coolest days on average
Lowest mean daily maximum temperature
14.6°C at Springwood
Coldest day
Lowest daily maximum temperature
10.8°C at Springwood on the 27th
Coldest night
Lowest temperature
−2.0°C at Richmond on the 23rd
Coolest nights on average
Lowest mean daily minimum temperature
5.4°C at Holsworthy
Warmest nights on average
Highest mean daily minimum temperature
9.4°C at Sydney (Observatory Hill)
Warmest night
Highest daily minimum temperature
13.8°C at Sydney Airport on the 8th
Wettest overall
Highest total rainfall
510.6 mm at Sydney (Observatory Hill)
Driest overall
Lowest total rainfall
209.0 mm at Camden Valley
Wettest day
Highest daily rainfall
147.4 mm at Berowra on the 9th
Highest wind gust
106 km/hr at Fort Denison on the 8th

Records for the Sydney area

Record lowest June mean daily maximum temperature
Mean daily maximum
for June 2007 (°C)
Previous lowest
for June
Years of
Normal for
Bankstown Airport


16.4 in 1983



Camden Airport


16.3 in 1983



Summaries for the Sydney area

Summary statistics for June 2007
Maximum temperatures
for June 2007
Minimum temperatures
for June 2007
June 2007
Mean for
Highest for
Mean for
Lowest for
Total for
Rank of
Fraction of
Sydney (Observatory Hill) 16.8 −0.9 20.7 2nd 9.4 −0.2 4.9 23rd 510.6 128.1 very high 399%
Camden Airport 16.2 −1.6 20.4 3rd 5.8 +1.6 −1.0 23rd 253.6 52.3 very high 488%
Parramatta 16.6 −1.2 20.4 3rd 7.8 +0.4 2.9 22nd 370.8 77.2 very high 482%
Penrith 16.7 −1.7 20.3 4th 7.6 +1.3 1.9 23rd 226.0 61.8 very high 365%
Springwood* 14.6 17.7 11th 6.8 1.2 22nd 280.0 75.7 very high 370%
Terrey Hills* 15.2 19.2 3rd 8.0 3.7 23rd 360.6

* new stations, no historic average temperatures available and no historic average rainfall available for Terrey Hills.

Additional climate data for Sydney (Observatory Hill) for June 2007

June 2007

Normal for June

Number of rain days



Average sunshine hours per day*



Average humidity at 3pm (%)



Number of thunderstorms



Number of windy days*



Number of gales*



* recorded at Sydney Airport


This statement has been prepared based on information available at noon on Monday 2 July 2007.  The data has been quality controlled, 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 - 2006 and Camden 1972 - 2006.  Rainfall averages and extremes for Observatory Hill are based on all years of record 1859 - 2006.

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