Wednesday, 3 August 2022 - Monthly Climate Summary for Greater Sydney - Product code IDCKGC15L0

Greater Sydney in July 2022: wettest on record

The total rainfall averaged over Greater Sydney made it the wettest July since records began in 1900. The majority of the rain fell in the first week of the month, as an East Coast Low brought intense rainfall and major flooding to the Hawkesbury-Nepean catchment. The mean monthly minimum temperatures were very much above average while mean maximum temperatures were below average.

Wettest July on record

• For Greater Sydney overall, it was the wettest July on record since 1900.
• Many sites recorded 5 to 8 times their July average rainfall.
• The majority of the rain fell in the first week of the month, as an East Coast Low developed off the Hunter Coast on the 2nd.
• The East Coast Low moved offshore on the 3rd, but onshore flow continued to bring persistent rain to Greater Sydney.
• The rainfall intensified on the 4th when a trough extending from the East Coast Low passed over Greater Sydney.
• The highest daily total at a Bureau gauge was 298.0 mm in the 24 hours to 9am 3 July at Darkes Forest in the far south of Greater Sydney.
• Many other sites also had their highest July daily rainfall on record.
• Darkes Forest also recorded the highest total for the month in Greater Sydney with 875.0 mm.
• Many other sites also had their highest total July rainfall on record or their highest for at least 20 years.

Warmer than average nights, cooler than average days

• Mean minimum temperatures were over 2 °C above their monthly average for many parts of Greater Sydney.
• The very wet first week was also associated with increased cloud cover and minimum temperatures between 5 to 10 °C above their July average during that period.
• The cloudy conditions during the month resulted in mean maximum temperatures around 0.5 to 1.5 °C below their July average.
• Camden Airport AWS and Horsley Park Equestrian Centre AWS had their lowest July mean daily maximum temperature since 1998.
• Badgerys Creek AWS had its equal warmest July night on record with 13.1 °C on the 7th.
• Some sites had their highest July mean daily minimum temperature on record and Badgerys Creek its highest July mean daily minimum temperature since 2001.

Sydney (Observatory Hill)

• Total rainfall for Sydney (Observatory Hill) was 404.0 mm, which is 420% of the average over all years at the former site of 96.3 mm, or 503% of the average over recent decades of 80.3 mm.
• The monthly total of 404.0 mm is a July record for Observatory Hill, exceeding the previous July record of 336.1 mm at the former site in 1950.
• The year-to-date (January to July) total of 1951.4 mm is also a record, exceeding the previous record of 1773.8 mm in 1890.
• 2022 is already the sixth-wettest year on record at Observatory Hill, with observations starting in 1858, and is 161% of the annual average over all years at the former site of 1213.4 mm.
• The mean daily maximum temperature for Sydney (Observatory Hill) was 17.0 °C, which is 0.6 °C above the average over all years at the former site of 16.4 °C, or 0.9 °C below the average over recent decades of 17.9 °C.
• The warmest day was 21.3 °C on the 17th, and the coolest day was on the 1st when the temperature reached 12.0 °C.
• The mean daily minimum temperature for Sydney (Observatory Hill) was 9.4 °C, which is 1.3 °C above the average over all year at the former site of 8.1 °C, or 0.5 °C above the average over recent decades of 8.9 °C.
• The coldest morning was 5.0 °C on the 16th, and the warmest morning was on the 5th when the minimum temperature was 14.4 °C.

Major flooding in the Hawkesbury-Nepean catchment

• The intense rainfall during the first week of the month, in addition to wet antecedent soil conditions, resulted in major flooding for the Hawkesbury-Nepean catchment.
• The river height at Menangle Bridge on the Nepean River peaked at 16.59 m on the 3rd, slightly lower than the level observed during the flooding in April 2022, but higher than the level observed in March 2022.

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