Monday, 2 April 2012 - Monthly Climate Summary for Sydney  - Product code IDCKGC25L0

Sydney in March 2012: Wettest March since 1984

• Wettest March since 1984.
• Wettest day in Sydney since 2007.
• Close to average temperatures.

Extremes Records Summaries Important notes the top

Rainfall

Sydney Observatory Hill recorded 269.8 mm of rain during March, double the historical average of 129.3 mm. Although only the 19th wettest March on record, this was the wettest for Sydney since 1984, with several other Sydney stations experiencing their wettest March since at least the 1980s. The rain fell over 15 days, close to normal for March, but 8 exceeded 10 mm, well above the historical average of 3 days, with three distinct rain events during the month.

Between the 1st and 5th, the low pressure trough system that drove heavy rain across southern NSW brought moderate rain to the Sydney region, with daily falls reaching 27.6 mm at Observatory Hill and 42 mm at Terrey Hills on the 1st. As a consequence of heavy rain in southern parts of the catchment, minor flooding was experienced in parts of western Sydney along the Hawkesbury-Nepean river. A further low pressure trough and associated thunderstorms also caused falls of up to 41.8 mm at Observatory Hill and 59.5 mm at North Rocks on the 17th.

However, the most significant rain event occurred on the 8th, when a short-lived East Coast Low caused daily falls of 109.4 mm at Observatory Hill and up to 134.4 mm at Lucas Heights. This is the wettest single day at Sydney Observatory Hill since an East Coast Low caused falls of 112.2 mm on 9 June 2007, and the wettest March day since 163.8 mm fell on 24 March 1984. Much of the rain fell during the morning peak hour, with 42.4 mm at Observatory Hill between 7:30 and 8:30 am, triggering widespread flash flooding and disruption of road and rail lines across the city, and 19 flood rescues by the SES.

At the end of March, Sydney's water storages were at 95.5% of capacity, an increase of 8% from the end of February and 20% higher than this time in 2011. For more information please see our Water Storages website.

Some sites had their highest total March rainfall on record.

Temperature

The average maximum temperature at Sydney Observatory Hill during March was 24.7 °C, average for March but the coolest days since March 2005. Temperatures were generally mild throughout the month, with no days exceeding 30 °C or cooler than 20 °C, below the historical averages of 1-2 days outside this range. Throughout the city, most areas were below average, consistent with the heavy rain during the month, with temperatures particularly cool at Parramatta North and Camden.

The average minimum temperature at Sydney Observatory Hill during March was 17.8 °C, slightly above the historical average of 17.6 °C, with nights close to average throughout the city. Most nights recorded minimums between 15 and 20 °C, normal for March, with the warmest night reaching 20.2 °C on the 15th and the coolest reaching 13.9 °C on the 24th. The average temperature at Sydney Observatory Hill was consequently 21.3 °C, close to the March average of 21.2 °C.

Wind

The prevailing wind direction at Sydney Airport during March was easterly, with 58% of 3pm winds between NE and SE, close to normal for March. However, 29% of 3pm winds were between W and S, slightly above average for March. There were six strong wind days reported at the Airport, slightly above the March average of four days, with gusts reaching 80 km/hr at Sydney Airport on the 1st.

Other phenomena

Sydney Airport recorded an average of 6.8 hours of bright sunshine during March, close to the historical average of 6.9 hours. There were two thunderstorms reported at the Airport during the month, normal for March, with three storms anywhere in the Metropolitan area.

Extremes Records Summaries Important notes the top

Extremes Records Summaries Important notes the top

Extremes Records Summaries Important notes the top

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.

Extremes Records Summaries Important notes the top