Tuesday, 2 October 2012 - Monthly Climate Summary for Sydney  - Product code IDCKGC15L0

Sydney in September 2012: Dry, warm, sunny start to Spring

• Eighth warmest September on record for maximum temperatures
• 6th warmest September day on record
• Coldest September night since 1995
• Sunniest September since 1987.

Extremes Records Summaries Important notes the top

Rainfall - Driest September since 2009

Sydney Observatory Hill recorded just 23.8 mm of rain during September, well below the historical average of 68.9 mm and the driest September since 16 mm fell during 2009, with dry conditions across the city. Only three days during the month recorded more than 1 mm (average 7 days), with only one day reaching 5 mm, the fewest since 2003 (0 days).

There were only two significant rain events during the month. On the 18th, widespread thunderstorms across the city produced only 3.6 mm at Observatory Hill, but 24 hour totals to 9am on the 19th reached 23 mm at Glenorie in northwest Sydney. Thunderstorms were also widespread across the city overnight on the 28th, with 24 hour totals to 9am on the 29th reaching 13.2 mm at Observatory Hill and 21 mm at Turramurra in northern Sydney.

Temperature - Warm days across the city, cool nights in the west

The average maximum temperature at Sydney Observatory Hill during September was 22.5 °C, 2.5 °C above the historical average and the 8th warmest September on record, with temperatures well above average across the city. Temperatures were warm throughout the month, with only three days dropping below 20 °C, the fewest on record for September (previous record 5 cool days in 2009 and 1980). However, only three days reached 25 °C, normal for September, with the majority of days recording mild temperatures between 20 and 23 °C.

Temperatures were particularly warm at the start of the month, with eleven days above 21 °C between the 3rd and 13th, the earliest such spell on record for Sydney, reaching 27 °C on the 5th and 6th. Temperatures were also very warm on the 28th, reaching 34.1 °C at Sydney Airport and 34.4 °C at Liverpool. Temperatures at Sydney Observatory Hill reached 33.2 °C, its 6th warmest September day on record.

Sydney Observatory Hill recorded an average minimum temperature of 12 °C, 0.9 °C above the historical average but the coolest September since 2004. Nights were generally cooler than normal in western Sydney, including the coldest September since 1994 at Richmond and Parramatta.

Nights were very cold at the start of the month, with a minimum temperature of 5.5 °C at Sydney Observatory Hill on the 1st, the coldest September night since 5.2 °C on 6 September 1995. This was the coldest September night on record at Camden, Parramatta, Richmond and Prospect Reservoir. In contrast, Sydney Observatory Hill recorded 18.4 °C on the 6th and 18.9 °C on the 28th; only eight other years have recorded two nights above 18 °C in September.

Other phenomena - Sunniest September since 1987

The prevailing wind direction at Sydney Airport during September was easterly, with 63% of 3pm winds between NE and SE. There were six strong wind days, normal for September, with a maximum wind gust of 80 km/hr on the 7th and some damage around the city.

The airport recorded an average of 9.2 hours of bright sunshine, well above the historical average of 7.9 hours and the sunniest September since 1987 (9.4 hours). Four days had thunderstorm activity in the Sydney region, with reports of small hail on the 18th.

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