The month of September 2023 is fast shaping up as a month that is significantly different to that of September 2022. In this regard, the first two weeks of the month have been drier with warmer days when compared to that of September 2022.
It is only a little over two weeks into the month and already the first 30 degree day of the spring and summer season 2023/24 has occurred across much of Western Sydney - at least in areas west of Parramatta. Compared to September 2022:
- There were no 30C days recorded.
- Across most of Sydney, the maximum temperature did not reach 30C at any time during the spring of 2022.
With the demise of La Nina, conditions have been very different to that of 12 months ago.
During September, 30C days can occur in many years across Western Sydney. During September 2017, there were 4 such days recorded at Penrith with 37.4C being recorded on the 23rd of that month.
The figure for Penrith over recent years since 2017 are:
- 2017 and 2018 - 4 days each for both years.
- 2019 and 2020 - 3 days each for both years.
- 2021 - 2 days.
- 2022 - 0 days.
The figure for Horsley Park is a little less being:
- 2017 and 2018 - 3 days each for both years.
- 2019 - 0 days.
- 2020 - 2 days.
- 2021 and 2022 - 0 days.
The figure for Sydney Observatory Hill is even less being:
- 2017 - 2 days.
- 2018 - 1 day.
- 2019 - 0 days.
- 2020 - 2 days.
- 2021 - 1 day.
- 2022 - 0 days.
Such days are more likely to occur inland than along the coast and the further inland one travels, the more such days that do occur.
On Friday 15 September 2023, the first 30C of the season occurred over much of Western Sydney with maximums of 30C to 32C being commonplace. Penrith was the warmest location reaching 32C followed by Richmond at 31.2C, 31C at Bankstown and 30.7C at Horsley Park (All Western Sydney).
Such heat did not penetrate east of Parramatta.
It even reached 30C at Nowra and 31.9C at Moruya on the New South Wales South Coast.
Inland New South Wales, similar maximum temperatures occurred across the west of the state with 30C to 33C being relatively common.
With a strong blocking high pressure system in place across the Tasman Sea and with westerly or north westerly winds expected to dominate, an interesting weather situation is emerging as maximum temperatures reaching 30C are being forecast for many centres across New South Wales across multiple days including:
- Nyngan - 6 days with forecasts as high as 35C between Sunday and Wednesday.
- Tibooburra - 6 days with forecasts as high as 35C for Sunday to Tuesday.
- Blacktown - 5 days with a forecast of 35C for Tuesday and Wednesday.
- Cobar - 5 days with a forecast of 36C for Monday.
- Dubbo - 5 days with a forecast of 33c for Monday.
- Penrith - 5 days with a forecast of 36C for Monday.
- Broken Hill - 4 days with a forecast of 35C for Monday and Tuesday.
- Ivanhoe - 4 days with a forecast of 37C for Monday.
- Wagga Wagga - 2 days with a forecast of 31C for Monday and Tuesday.
When reviewing this more closely, much of the state should experience 30C maximum temperatures in coming days except along the southern border areas, coastal areas and the tablelands and ranges. This is potentially a very significant weather event for the state of New South Wales for September.
It is identified that after Wednesday 20 September 2023, a cool change will be crossing through New South Wales that will bring an end to the heat.
The photos of the sunrise at Blacktown on Saturday morning provides a clue that another 30C day should occur with a forecast of 32C to 33C expected for Saturday across much of Western Sydney.