Monday 2 April 2007 - Monthly Climate Summary for Sydney - Product code IDCKGC15L0

Sydney has warm and humid March

Main points:

  • Warm days, 7th highest average maximum temperature
  • Warm nights, 8th highest average minimum temperature
  • Below average rainfall, except for far western and northern suburbs
  • Periods of high humidity
  • Hours of sunshine were average

Temperature

Sydney experienced very warm daytime temperatures during March with extended periods of high humidity. The average maximum (daytime) temperature at Observatory Hill was 26.3°C, or 1.1°C above the historic average1of 25.2°C.  This ranks 7th highest on record for March.  There were 4 hot days (temperature exceeding 30°C) during March, twice the historic average of 2 hot days. Slightly warmer average daytime temperatures were experienced in the western suburbs where average maximum temperatures were about 1°C higher than coastal suburbs. Prevailing sea-breezes helped to modify temperatures along the coast. Elevated locations such as Springwood recorded daytime temperatures about 1°C cooler than coastal Sydney.

Nights were also very warm and humid during March. The average minimum temperature at Sydney (Observatory Hill) of 19.0°C was 1.0°C above the historic March average1. This is the 8th highest on record for March with last year recording the highest on record (19.6°C) .  The mild overnight temperatures were due to a combination of high humidity, the persistence of cloudy or partly cloudy nights and the lack of any significant southerly changes. 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 15.0°C, the lowest in the Sydney area.  

The highest temperature at Sydney (Observatory Hill) during March was 35.1°C on the 24th.  The lowest temperature was 14.0°C on the 31st.   Corresponding extremes in the Sydney area ranged from 36.7°C at Prospect Dam and Sydney Olympic Park on the 3rd to 7.1°C at Richmond on the 31st.

Rainfall

The total monthly rainfall of 65.4mm at Sydney Observatory Hill was below the historic March average of 130.3 mm.  There were 14 rain days, which is slightly above the historic average for March. Rainfall totals varied greatly over the Metropolitan area during March due mainly to frequent thunderstorm activity. Monthly totals were highest in the northern suburbs and far western suburbs and lowest in the Baulkham Hills area and the south-east.  Totals ranged from 159 mm at Avalon in Sydney's northern beaches and 157.8mm at Badgerys Creek in the far west to a low of 41 mm at Baulkham Hills in the north-west.

Moderate to locally heavy rain in the lower Warragamba Dam catchment during March was mainly from thunderstorm activity with totals ranging from 100 to 160mm for the month. However, the upper catchment received lighter falls with around 50 to 80mm 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

Other phenomena

High humidity at times during March combined with above average temperatures caused periods of uncomfortable weather.   One such period from 17th to 24th saw humidity varying between 70% and 85% and temperatures in the high 20's, making conditions more typical of the northern Queensland coast.   Four thunderstorms were recorded over Sydney metropolitan area with 3 storms at Sydney Observatory Hill (average 2 storms). Thunderstorms with heavy rain affected far western suburbs on the 1st and 5th while the northern beaches were hit by a severe storm on the 20th.  During a thunderstorm at Camden on the 5th, 30 mm fell in just 17 minutes, which has a recurrence interval of about 20−50 years, and strong winds reached 109 km/h.  At Avalon on the northern beaches,  41 mm was recorded in 1 hour during a thunderstorm on the evening of the 20th.  Sunshine hours averaged 6.8 hours per day which is average for March.

Further information

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

Extremes for the Sydney area

Hottest day
Highest temperature
36.7°C at Prospect Dam and Sydney Olympic Park on the 3rd
Warmest days on average
Highest mean daily maximum temperature
27.6°C at Liverpool
Coolest days on average
Lowest mean daily maximum temperature
25.1°C at Springwood
Coldest day
Lowest daily maximum temperature
17.8°C at Springwood on the 25th
Coldest night
Lowest temperature
 7.1°C at Richmond on the 31st
Coolest nights on average
Lowest mean daily minimum temperature
15.0°C at Springwood
Warmest nights on average
Highest mean daily minimum temperature
19.0°C at Sydney (Observatory Hill)
Warmest night
Highest daily minimum temperature
23.0°C at Sydney (Observatory Hill) on the 4th
Wettest overall
Highest total rainfall
159.0 mm at Avalon
Driest overall
Lowest total rainfall
41.0 mm at Baulkham Hills
Wettest day
Highest daily rainfall
67 mm at Avalon (24 hours to 9am on 21st)
Highest wind gust
109 km/h at Camden on the 5th

Summaries

Summary statistics for the Sydney area for March 2007
Maximum temperatures
March 2007
(°C)
Minimum temperatures
March 2007
(°C)
Rainfall
March 2007
(millimetres)
Mean for
March
Diff
from
normal
Highest for
March
Mean for
March
Diff
from
normal
Lowest for
March
Total
for
March
Normal
for
March
Rank of
March
Fraction of
March
normal
Sydney (Observatory Hill) 26.3 +1.1 35.1 24th 19.0 +1.0 14.0 31st 65.4 130.3 low 50%
Parramatta 27.5 +1.3 36.5 3rd 16.8 +1.0 9.6 31st 63.4 110.2 low 58%
Richmond 27.2 +0.2 35.9 3rd 16.2 +0.4 7.1 31st 86.6 92.1 normal 94%
Camden 26.5 −0.2 35.4 3rd 15.8 +1.1 8.7 28th 113.0 86.1 high 131%
Terrey Hills* 25.7  

33.3

24th

17.0

 

11.8

31st

68.0

 

 

 

Springwood* 25.1 35.5 3rd 15.0 9.0 31st 94.8 126.2 normal 75%

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

Summary phenomena for Sydney (Observatory Hill) for March
 

March 2007

Normal for March

Number of rain days

 14

 13

Average sunshine hours per day*

 6.8

6.8

Average humidity at 9am (%)

72

74

Number of thunderstorms

 3

 2

Number of windy days*

 8

 4

* recorded at Sydney Airport


Notes

This statement has been prepared based on information available at noon on Monday 2 April 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.