Sydney weather in September
Temperature, sea and sunshine in September: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in September
Excellent
Best time to visit: July – May
What is the weather like in Sydney in September?
In September, Sydney is mild: daytime highs average 20 °C, and nights cool down to about 12 °C. The sea averages 18.5 °C – bracing, so a wetsuit helps for longer swims. The sun shines for around 8 hours a day. Rain falls on about 7 days, adding up to 38 mm. All in all, September is an excellent month for a holiday in Sydney.
September compared
How the weather changes from August to October. Tap a month to open it.
| AugustAug | SeptemberSep | OctoberOct | |
|---|---|---|---|
| Score | 88 | 91 | 87 |
| Day | 17° | 20° | 21° |
| Night | 10° | 12° | 15° |
| Sea | 18° | 19° | 19° |
| Sun | 8 h | 8 h | 8 h |
| Rain days | 6 | 7 | 8 |
More details for September
- Daylight
- 11 h 50 min05:55 – 17:46
- UV index
- 7 · highclear sky, noon (estimate)All months
- Muggy days
- 0 daysdew point 18 °C or more
- Wind
- 18 km/haverage daily peak
- Cloud cover
- 38 %on average
- Hot days
- 0 days30 °C or more
- Time zone
- UTC+10Australia/Sydney
How the score comes together
- Temperatureweight 50 %100 %
- Sunshineweight 20 %83 %
- Few rainy daysweight 30 %82 %
Each factor is rated from 0 to 100 % and weighted for the travel style “City break”.
What to pack in September
- Wetsuit for longer swims
- Sunscreen
- Sunglasses & sun hat
- A jumper for the evenings
Sydney in September: quick answers
Is Sydney hot in September?
No. In September, Sydney is mild: daytime highs average 20 °C and nights drop to about 12 °C.
Can you swim in Sydney in September?
Only if you don't mind cold water: in September the sea averages just 18.5 °C. Comfortable swimming is possible from November to May.
Does it rain much in Sydney in September?
Rain falls on about 7 days, adding up to 38 mm.
Sydney month by month
The whole year in SydneyAll destinations: AustraliaWhere to go in SeptemberSea temperature in September
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0)