Tuesday, 1 March 2011 - Seasonal Climate Summary for Sydney - Greater Sydney - Product code IDCKGC25L0

Sydney in summer 2010-11: A dry summer with very warm nights

• Equal 2nd warmest summer on record for minimum temperatures.
• 8th warmest summer on record for maximums.
• 12th consecutive summer with above average temperatures.
• Below average rainfall.

Extremes Records Summaries Important notes the top

Rainfall

Sydney Observatory Hill recorded 155mm of rain during summer 2011, approximately half the historical average of 298.1mm and the driest summer since 2002/2003 (148mm). The majority of rain occured during December 2010 when 83.2mm fell, with both January and February recording well below average rainfall. However, rainfall varied significantly through the metropolitan region, with highest falls in the Blue Mountains including 326.2mm at Valley Heights.

The rain fell over 37 rain days, close to the historical average of 36 days. However, only three days above 10mm were recorded at Observatory Hill during summer compared to an average of 8 days, all of which occurred in December, with the highest daily fall of just 27.6mm on December 1. Daily totals of over 50mm were recorded at other suburban stations on December 1, December 6, January 3 and January 9, generally associated with isolated thunderstorms.

Temperature

Maximum temperatures at Observatory Hill averaged 27.2 °C during summer, 1.6 °C above the historical average of 25.6 °C. This was the 8th warmest summer on record for maximum temperatures, and the warmest summer since 2005. Temperatures warmed throughout the season, with slightly above average temperatures in December but near-record maximums in February, including a record-breaking heatwave between January 31 and February 6. The warmest day of the season was on February 5 2011, but very warm days were also experienced on the 26th-27th and 30th-31st of January.

Minimum temperatures during summer averaged 20.3 °C at Observatory Hill, 2.0 °C above the historical average of 18.3 °C. This was the equal second warmest summer on record, equal to summer 2009/10, and the 16th consecutive summer with above average minimums. Minimum temperatures were well above average throughout the season, with the 9th warmest December on record followed by the 2nd warmest January and February on record. Temperatures were particularly warm during the first week of February, with several records broken throughout the Metropolitan region for daily minimums and the numbers of consecutive warm days.

The mean summer temperature was consequently 23.8 °C, the twelth consecutive summer with above average temperatures at Observatory Hill and the 5th warmest summer on record. For more information on the warm temperatures in Sydney during February see the February Monthly Summary or Special Climate Statement 27, released 8th February.

Some sites had their warmest summer night (highest daily minimum temperature) on record.

Wind

Winds at Sydney Airport were predominantly easterly during summer, with 52% of 3pm winds from an E-NE direction and 88% of 3pm winds arising between NE and S. Thirteen strong wind days were observed during summer, below the historical average of 19 days, with the maximum wind gust of 91km/hr recorded due to a strong cold change on February 6.

Other phenomena

Sydney Airport recorded an average of 7.2 sunshine hours per day during summer, close to the historical average of 7.1 hours per day. Only five thunderstorms were reported at the Airport during the season, well below the historical average of 9 and the lowest frequency since summer 2002/3, with only six storms anywhere in the metropolitan region.

Extremes Records Summaries Important notes the top

Extremes Records Summaries Important notes the top

Extremes Records Summaries Important notes the top