Thursday 1 March 2007 - Monthly Climate Summary for Sydney - Product code IDCKGC15L0

Sydney has mild, wet February

Heavy rain in western suburbs while the east received much lighter falls. Mild temperatures.

Main points:

  • Close to average rainfall along coast, well above average in western suburbs
  • Mild days along the coast, warmer inland
  • Mild to warm and humid nights, especially along the coast
  • Above average sunshine

Rainfall

The total monthly rainfall of 107.6 mm at Sydney Observatory Hill was close to the historic February average of 117.0 mm.  There were 11 rain days, which is slightly below the historic average of 12 rain days.   In a reversal of the usual pattern, Metropolitan rainfall totals were highest in the south-western suburbs and lowest in the east. February totals ranged from 257.8 mm at Campbelltown (Kentlyn) in Sydney's south-west to 101 mm at Avalon on the northern beaches.  Most of this rain was from thunderstorm and shower activity.  It has been at least 25 years since monthly rainfall totals over such a wide area of the western suburbs have exceeded monthly totals for coastal suburbs by such a great amount.

On the 12th and 13th, heavy rain over the western suburbs caused rises in stream levels and flooding in the Campbelltown area.  The 103.6 mm on the Badgerys Creek on the 12th was the wettest day at that location for 17 years.  At Camden the 93.4 mm on the 12th was the wettest day for 15 years.

Heavy rain fell in the lower Warragamba Dam catchment during February, with Warragamba Dam recording 175 mm for the month.  However, the upper catchment received lighter falls with monthly totals of 50−100 mm in the Goulburn area.   Recent rainfall in Sydney's catchments can be found on the Sydney Catchment Authority web site at: http://www.sca.nsw.gov.au/dams/rainfall.html

Temperature

Coastal Sydney experienced mild daytime temperatures during February. The average maximum (daytime) temperature at Observatory Hill was 26.0°C, or 0.2°C below the historic average1of 26.2°C.  This is the lowest for February since 2002 when 25.2°C was recorded.  There was a noticeable absence of hot days (temperature exceeding 30°C) with nil recorded during February compared to the historic average of 2 hot days. The cooling affect of prevailing south-east to north-east sea-breezes contributed towards the mild temperatures along the coast.  Slightly warmer daytime temperatures were experienced in the western suburbs where average maximum temperatures were about 2−3°C higher than coastal suburbs.

Nights were mild to warm and humid, especially in coastal Sydney during February. The average minimum temperature at Sydney (Observatory Hill) of 20.6°C was 1.3°C above the historic February average1. This is the 4th highest on record for February and the highest since 20.8°C in 1998.   The far west and lower Blue Mountains recorded minimum temperatures about 3−4°C cooler than coastal suburbs.  At Springwood (elevation 362 metres) the average minimum was 16.6°C, the lowest in the Sydney area.

The highest temperature at Sydney (Observatory Hill) during February was only 27.7°C on the 10th. This is the first time since 1957that the temperature has failed to exceed 28°C in February.  The lowest temperature was 17.7°C on the 13th. Corresponding extremes in the Sydney area ranged from 34.7°C at Penrith on the 3rd to 14.1°C at Springwood on the 15th.

Other phenomena

Sunshine hours were above average during February with an average of 7.8 hours per day compared to the historic February average of  7.3 hours per day.  Four thunderstorms were recorded at Sydney Observatory Hill (average 2 storms).  On the last day of the month the Campbelltown area experienced flash flooding for the second time in February after thunderstorms caused heavy rain which flooded roads and buildings.  Several people had to be rescued from cars swept away by flood waters. Lightning strikes injured several people and damaged railway signalling equipment.

Further information

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

Extremes

Hottest day
Highest temperature
34.7°C at Penrith on the 3rd
Warmest days on average
Highest mean daily maximum temperature
29.3°C at Penrith
Coolest days on average
Lowest mean daily maximum temperature
26.0°C at Sydney (Observatory Hill)
Coldest day
Lowest daily maximum temperature
18.2°C at Springwood on the 12th
Coldest night
Lowest temperature
14.1°C at Springwood on the 15th
Coolest nights on average
Lowest mean daily minimum temperature
16.6°C at Springwood
Warmest nights on average
Highest mean daily minimum temperature
20.6°C at Sydney (Observatory Hill)
Warmest night
Highest daily minimum temperature
22.6°C at Sydney (Observatory Hill) on the 11th
Wettest overall
Highest total rainfall
257.8 mm at Campbelltown (Kentlyn)
Driest overall
Lowest total rainfall
101 mm at Avalon
Wettest day
Highest daily rainfall
103.6 mm at Badgerys Creek on the 12th
Highest wind gust
104 km/h at Penrith on the 24th

Summaries 

Summary statistics for February 2007
Maximum temperatures
February 2007
(°C)
Minimum temperatures
February 2007
(°C)
Rainfall
February 2007
(millimetres)
Mean for
February
Diff
from
normal
Highest for
February
Mean for
February
Diff
from
normal
Lowest for
February
Total
for
February
Normal
for
February
Rank of
February
Fraction of
February
normal
Sydney (Observatory Hill) 26.0 −0.2 27.7 10th 20.6 +1.3 17.7 13th 107.6 117.0 normal   92%
Parramatta 28.1 +0.2 32.9 24th 18.2 +0.7 16.0 14th 214.2 123.4 very high 174%
Richmond 28.6 normal 33.9 24th 18.2 +0.7 15.9 15th 189.0 105.6 high 179%
Camden 28.6 normal 33.9 3rd 17.8 +1.1 14.6 14th 203.4   95.9 high 212%
Springwood* 26.3 31.0 24th 16.6 14.1 15th 189.2 136.3 high 139%

* new station, no historic average temperatures available     Note: Terrey Hills unavailable due to missing data.

Summary phenomena for Sydney (Observatory Hill) for February
 

February 2007

Normal for February

Number of rain days

 11

12

Average sunshine hours per day*

 7.8

7.3

Average humidity at 3pm (%)

66

64

Number of thunderstorms

 4

2

Number of windy days*

 3

5

* recorded at Sydney Airport


Notes

This statement has been prepared based on information available at noon on Thursday 1 March 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 - 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.