Tuesday, 1 September 2020 - Seasonal Climate Summary for Greater Sydney - Product code IDCKGC25L0

Greater Sydney in winter 2020: Near to above average temperatures and rainfall

Winter was fairly typical in 2020 for temperature, with both mean minimum and mean maximum temperature being close to or just above average. Rainfall was generally above average for most parts, mostly as a result of several significant rainfall events in July and August. These events also resulted in significant coastal erosion, snowfalls and damaging winds.

Near to above average rainfall

• In general, rainfall in winter across Greater Sydney was near or above average, with totals ranging from 98% of average at Sydney Airport, to 168% of average at Mount Boyce in the Blue Mountains.
• Most of Greater Sydney received below average rainfall in June, with few significant rainfall events affecting the area; in contrast, July and August both recorded above average rainfall, with several low pressure and frontal systems bringing wet and wintry conditions to the region.
• The most significant event of winter was a result of a coastal low pressure system which developed on 26 July; the heaviest falls in Greater Sydney fell between the 26-28 July, with widespread 3 day totals exceeding 100 mm.
• Other notable events included a Tasman low pressure system from 13-15 July which brought moderate shower activity to the area, but was more significant in terms of the large and powerful waves it produced; and a series of cold fronts and a complex low pressure systems from 7-10 August, which resulted in widespread three day totals of 50 mm to 80 mm.
• There were 39 rain days at Sydney (Observatory Hill), just above average for winter (34 days).
• Sunshine was typical for winter at Sydney Airport with 6.5 hours of bright sunshine on average per day.

Near to above average temperatures

• Daytime temperatures were warmer than average in June and July, and close to average in August, resulting in the overall mean maximum temperature being slightly above average for winter.
• Most sites were up to 1 °C warmer than average, but ranging from 0.3 °C below average at Cooranbong (Lake Macquarie AWS) to 1.6 °C above average at Katoomba (Farnells Rd).
• The warmest winter day was on 30 August, where temperatures exceeded 25 °C across most Sydney basin sites; Badgerys Creek recorded 28.6 °C on this day, the warmest winter day for 2020.
• The start of July also saw an unseasonably warm spell with daytime temperatures reaching the low to mid 20's on the 2nd.
• Overnight temperatures were close to average in June and August, and above average in July, resulting in the overall mean minimum temperature being slightly above average for winter.
• Most sites were up to up to 1 °C warmer than average, but ranging from 0.3 °C below average at Katoomba (Farnells Rd) and Mangrove Mountain to 1.6 °C above average at Sydney Airport.
• The coldest night for winter was recorded on 25 August at Mount Boyce in the Blue Mountains, where the temperature dropped to -2.5 °C.

Sydney (Observatory Hill)

• Total rainfall for Sydney (Observatory Hill) was 320.4 mm, which is 103% of the long-term average of 311.3 mm.
• The mean daily maximum temperature for Sydney (Observatory Hill) was 18.6 °C, which is 1.5 °C above the long-term average of 17.1 °C.
• The warmest day was 25.3 °C on 30 August, and the coolest day was on 7 August when the temperature reached 13.6 °C.
• The mean daily minimum temperature for Sydney (Observatory Hill) was 9.7 °C, which is 0.9 °C above the long-term average of 8.8 °C.
• The coldest morning was 6.3 °C on 5 August, and the warmest morning was on 1 June when the minimum temperature was 14.5 °C

Other phenomena

• A deep low pressure system over the Tasman Sea generated very large and powerful waves along the NSW coast from 14 July, which resulted in hazardous beach conditions and coastal erosion, particularly along the coastal area near Wamberal. Peak waves exceeding 11.5 metres were recorded by the wave rider buoy offshore of Sydney. Wind gusts of 109 km/h were recorded at Wattamolla and 96km/h at Norah Head.
• A significant rain event from 7-10 August and continued inflows after the event, saw Warragamba dam spill on the 16 August for the first time since July 2016. Levels had dropped to 42.7% in February 2020.
• A vigorous cold front on 22 August brought snow to the Blue Mountains, with reports at Blackheath and Katoomba.

Extremes Maps Records Summaries Important notes the top

Extremes Maps Records Summaries Important notes the top

Extremes Maps Records Summaries Important notes the top