During September, 30C maximum daytime temperatures can occur throughout Sydney and especially across the western parts of the city. However, there are years where such days are missing such as what occurred during 2022.
As such, 30C maximum daytime temperatures are not recorded every year during September across the city.
In the case of 2026, an El Nino event across the Pacific Ocean is having an impact on what is occurring in terms of the daily weather.
During the weekend of Saturday and Sunday 19 and 20 September, two consecutive days have occurred where maximum temperatures have reached 30C across much of Sydney. This makes it the warmest consecutive Saturday and Sunday since the 21 and 22 February 2026 where maximum temperatures across both days soared to the mid 30s, especially across Western Sydney.
Having two 30C days in a row in September is rare across Western Sydney but it has happened in years gone by such as what occurred between the 15 and the 20 September 2023 when 6 days in a row occurred where daytime temperatures exceeded 30C.
During Saturday, maximum temperatures across much of Sydney peaked at around 30C to 31C.
During Sunday, maximum daytime temperatures soared into the low 30s to 3pm as follows:
- Penrith – 33.8C.
- Horsley Park – 33.3C
- Sydney Olympic Park.- 33.7C.
- Sydney Observatory Hill – 28.4C (The sea breeze has had a cooling effect along coastal Sydney).
So far this September, temperatures have reached 30C on 3 days to date for the month and it is possible that one or two more may occur before the month concludes.
A warmer than normal Spring is expected and what is occurring during September is one element of what is generally forecast for spring 2026.
Such warm days have been coming ahead of strong cold changes which has seen wide fluctuations of temperatures from as high as 33C down to as low as 17C or 18C following the passages of the changes but little rainfall occurring.
It is likely that this trend will continue for the foreseeable future.