Tuesday, 1 September 2020 - Monthly Climate Summary for Greater Sydney - Product code IDCKGC15L0

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

Greater Sydney experienced near average daytime and night time temperatures in August. Rainfall was near or above average overall, but with a significant event affecting the area from the 7th to 10th.

Near to above average rainfall

• Rainfall was generally close to average near the coast and to the north, and above average further inland and to the south-west; totals ranged from 79% of average at Sydney Airport to 220% of average at Campbelltown (Mount Annan).
• It was a dry start and end to the month, with the majority of the rainfall being recorded during the middle two weeks of August.
• The most significant rainfall was recorded between the 7th and 10th, as a series of cold fronts and a complex low pressure system affected the region; the highest falls were recorded for the 24 hours to 9 am on the 10th, with Wedderburn (Booalbyn) in the region's south-west, recording 74.0 mm for this period (refer to the relevant Weekly Rainfall Update for more information about the event).
• Blackheath (Wombat St) in the Blue Mountains recorded its highest August daily rainfall on record, also on the 10th, and was the wettest location for the month with 122 mm for August.
• Winter frontal systems delivered further rainfall during the month, with the falls recorded on the 13th, 15th, and 20th.
• Camden Airport had its highest total August rainfall for at least 20 years.
• Sydney (Observatory Hill) reported rainfall on 8 days, which is fewer than the August average of around 10 days.
• Sydney Airport had on average 8 hours of bright sunshine per day, which is close to average for August.
• The year-to-date rainfall for Sydney (Observatory Hill) is 1140.2 mm, above the January to August average of 909 mm.

Average days and nights

• Mean maximum temperatures were generally within 1 °C of average throughout, ranging from 0.7 °C below average at Horsley Park, to 1.3 °C above average at Sydney (Observatory Hill).
• It was a warm end to August with most Sydney basin sites exceeding 25 °C on the 30th; Badgerys Creek recorded the hottest day of the month, reaching 28.6 °C on this day, its equal second-warmest August day on record.
• Particularly cold and windy conditions were experienced on the 7th with maximum temperatures reaching only the low teens through most parts, but feeling even colder with the wind chill factor; these cool conditions persisted from the 5th to 12th, as a result of low pressure systems bringing cool and unstable air across the region.
• Richmond RAAF had its coldest August day (lowest maximum temperature) in its 27 years of record on the 7th.
• Another cold outbreak affected Greater Sydney on the 22nd, with the passage of a vigorous cold front; this event also brought snow to areas in the Blue Mountains, with snow reported at Blackheath and Katoomba.
• Mean minimum temperatures were also generally within 1 °C of average throughout, ranging from 0.7 °C below average at Katoomba (Farnells Rd) to 1.2 °C above average at Sydney Airport.
• The coolest nights were experienced on the 5th and 6th, and from the 25th to 27th under the influence of high pressure ridges bringing clear skies and light winds.
• Richmond RAAF experienced 2 nights below 0 °C, which is below the average of 4 days for August.
• For Sydney (Observatory Hill) the year-to-date mean maximum and mean minimum temperatures still remain above average, with a mean maximum temperature of 22.6, 1.4 °C above average and mean minimum temperature of 14.4 °C, 0.9 °C above average, for the January to August period.

Sydney (Observatory Hill)

• Total rainfall for Sydney (Observatory Hill) was 68.2 mm, which is 85% of the long-term average of 80.2 mm.
• The mean daily maximum temperature for Sydney (Observatory Hill) was 19.2 °C, which is 1.3 °C above the long-term average of 17.9 °C.
• The warmest day was 25.3 °C on the 30th, and the coolest day was on the 7th when the temperature reached 13.6 °C.
• The mean daily minimum temperature for Sydney (Observatory Hill) was 9.4 °C, which is 0.4 °C above the long-term average of 9.0 °C.
• The coldest morning was 6.3 °C on the 5th, and the warmest morning was on the 31st when the minimum temperature was 12.7 °C.

Other phenomena

• As a result of the wet weather from the 7th to 10th and continued inflows after the event, Warragamba dam spilled on the 16th, the first time since July 2016. Levels had dropped to 42.7% in February 2020.

Extremes Maps Records Summaries Daily observations Important notes the top

Extremes Maps Records Summaries Daily observations Important notes the top

* note: there are gaps in the historical record at this site, so it is possible a higher value has gone unreported

Extremes Maps Records Summaries Daily observations Important notes the top

Extremes Maps Records Summaries Daily observations Important notes the top

Extremes Maps Records Summaries Daily observations Important notes the top