Friday, 8 January 2021 - Monthly Climate Summary for Greater Sydney - Product code IDCKGC15L0

Greater Sydney in December 2020: a wet month

December was a wet month for Greater Sydney with a large number of rain days. Maximum temperatures were below average except near the coast, while minimum temperatures were close to average.

Rainfall above average

• Rainfall was above average in most parts of Greater Sydney.
• It was particularly wet on the Central Coast and some northern suburbs, with rainfall in these areas more than double the December average.
• Near-average December rainfall occurred in some southern and south-western suburbs.
• The number of days with rain was significantly above average, especially in western Sydney. Richmond had 20 days with rain, about double the December average and the second-highest on record for December after 2007.
• Rain was especially frequent in the second half of the month, falling on most days at the majority of sites from the 14th onwards, except between the 23rd and 25th.
• St. Ives (Richmond Avenue) had its highest December daily rainfall on record
• Some sites on the Central Coast had their highest total December rainfall on record
• Some sites had their highest total December rainfall for at least 20 years

Cool days in western Sydney

• Maximum temperatures were well below average at most locations in western Sydney, where it was the coolest December since 2011, and the Blue Mountains, although they were near average at some coastal sites.
• Minimum temperatures were near average throughout Greater Sydney.

Sydney (Observatory Hill)

• Total rainfall for Sydney (Observatory Hill) was 119.0 mm, 55% above the average at the former Observatory Hill site.
• The mean daily maximum temperature for Sydney (Observatory Hill) was 26.1 °C, 0.9 °C above the average at the former Observatory Hill site.
• The warmest day was 30.8 °C on the 7th, and the coolest day was on the 19th when the temperature reached 19.6 °C.
• The mean daily minimum temperature for Sydney (Observatory Hill) was 18.1 °C, 0.5 °C above the average at the former Observatory Hill site.
• The coldest morning was 14.4 °C on the 9th, and the warmest morning was on the 18th when the minimum temperature was 22.2 °C.

Severe thunderstorms early in the month

• Severe thunderstorms affected Greater Sydney on the 1st, with power outages and some tree damage in high winds. A gust of 106 km/h was reported at Richmond.
• Heavy rain fell in parts of the Northern Beaches area on the 30th, with localised flash flooding.

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