September is one of the cooler months of the year in Sydney, with average highs near 19.3°C and lows around 13.4°C (mean 16.4°C). It is one of the drier months, averaging 52 mm of rainfall and 70% relative humidity across the period.
September is one of the cooler months of the year in Sydney. Across 45 years of records, the warmest September in Sydney was 2013 — when the month averaged 18.4°C — while the coldest was 1990 at 14.5°C. Typical September days reach 19.3°C with nights near 13.4°C. The long-term trend is warming, about 0.4°C per decade.
September is one of the drier months in Sydney, averaging 52 mm of rainfall. The wettest September on record was 1995 with 181 mm, while the driest was 2017 at 1 mm.
Relative humidity in Sydney during September averages 70%. The most humid September was 1998 at 78%, and the least humid was 2017 at 56%.
September receives about 4.8 kWh/m²/day of solar energy in Sydney. The sunniest September was 2017 at 5.4 kWh/m²/day, and the cloudiest were 1995 and 2022 at 4.2.
Average wind speed in Sydney during September is 3.2 m/s. The windiest Septembers were 2015, 2021 and 2022, among others at 3.5 m/s, while the calmest were 1987 and 2023 at 2.7 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 15.6°C | 15.6°C | 16.9°C | 16.6°C | 17.2°C | +1.6°C |
| Avg High | 18.5°C | 18.3°C | 19.9°C | 19.6°C | 20.2°C | +1.7°C |
| Avg Low | 12.7°C | 12.8°C | 13.8°C | 13.7°C | 14.1°C | +1.4°C |
| Avg Rain | 58 mm | 70 mm | 47 mm | 41 mm | 40 mm | -19 mm |
September temperatures in Sydney have risen by about 1.6°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 8.1°C (1982) to a record high of 29.7°C (2023).
Rainfall in September is one of the drier months, averaging 52 mm, with a wettest year of 181 mm.
A quieter season to visit Sydney
If your dates are flexible, the more temperate months of December and March tend to be the most comfortable for visiting Sydney. That said, September — with days averaging 19.3°C and nights around 13.4°C (mean 16.4°C) and moderate rainfall (52 mm) — can still be rewarding for travellers who don't mind the cooler conditions, and often means fewer crowds.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 20.5°C | 17.5°C | 14.4°C | 25.6°C | 11.0°C | 58 mm | 69% | 3.1 m/s | 5.1 |
| 2024 | 21.2°C | 17.8°C | 14.3°C | 26.5°C | 10.7°C | 27 mm | 61% | 3.3 m/s | 4.7 |
| 2023 | 21.9°C | 18.3°C | 14.8°C | 29.7°C | 10.6°C | 14 mm | 63% | 2.7 m/s | 5.2 |
| 2022 | 17.9°C | 15.9°C | 13.9°C | 20.1°C | 10.9°C | 91 mm | 77% | 3.5 m/s | 4.2 |
| 2021 | 20.0°C | 16.7°C | 13.4°C | 25.0°C | 10.3°C | 27 mm | 68% | 3.5 m/s | 5 |
| 2020 | 19.7°C | 16.7°C | 13.7°C | 26.0°C | 10.3°C | 22 mm | 71% | 2.9 m/s | 4.8 |
| 2019 | 19.8°C | 16.7°C | 13.7°C | 25.1°C | 11.1°C | 56 mm | 68% | 3.3 m/s | 4.9 |
| 2018 | 19.0°C | 16.0°C | 13.1°C | 26.2°C | 10.2°C | 35 mm | 68% | 3.1 m/s | 4.7 |
| 2017 | 21.1°C | 17.4°C | 13.8°C | 28.7°C | 11.0°C | 1 mm | 56% | 3.3 m/s | 5.4 |
| 2016 | 19.3°C | 16.6°C | 14.0°C | 20.9°C | 11.2°C | 49 mm | 73% | 3.3 m/s | 4.5 |
| 2015 | 18.7°C | 16.3°C | 13.9°C | 24.8°C | 10.4°C | 27 mm | 71% | 3.5 m/s | 4.7 |
| 2014 | 18.8°C | 16.2°C | 13.6°C | 27.5°C | 11.1°C | 32 mm | 73% | 3.2 m/s | 4.8 |
| 2013 🔥 | 21.7°C | 18.4°C | 15.1°C | 27.2°C | 12.5°C | 50 mm | 66% | 3 m/s | 5 |
| 2012 | 19.9°C | 16.5°C | 13.2°C | 26.7°C | 9.4°C | 28 mm | 67% | 2.9 m/s | 5.2 |
| 2011 | 19.1°C | 16.2°C | 13.3°C | 25.6°C | 9.4°C | 77 mm | 70% | 3.3 m/s | 4.6 |
| 2010 | 18.9°C | 15.9°C | 13.0°C | 23.2°C | 10.5°C | 54 mm | 71% | 3 m/s | 4.6 |
| 2009 | 20.7°C | 17.4°C | 14.1°C | 26.4°C | 10.7°C | 21 mm | 65% | 3.1 m/s | 5 |
| 2008 | 19.0°C | 16.0°C | 13.0°C | 26.3°C | 9.5°C | 69 mm | 70% | 3.2 m/s | 4.8 |
| 2007 | 18.5°C | 16.0°C | 13.4°C | 23.2°C | 11.2°C | 33 mm | 71% | 3.2 m/s | 4.9 |
| 2006 | 20.2°C | 17.4°C | 14.7°C | 26.7°C | 12.5°C | 118 mm | 70% | 3.4 m/s | 4.8 |
| 2005 | 19.2°C | 16.3°C | 13.4°C | 24.3°C | 11.2°C | 62 mm | 71% | 3.3 m/s | 4.6 |
| 2004 | 19.6°C | 16.5°C | 13.5°C | 26.7°C | 10.1°C | 63 mm | 69% | 2.8 m/s | 4.4 |
| 2003 | 19.8°C | 16.5°C | 13.3°C | 28.0°C | 10.1°C | 11 mm | 63% | 3.2 m/s | 5 |
| 2002 | 20.8°C | 17.3°C | 13.9°C | 26.4°C | 10.8°C | 19 mm | 64% | 3.2 m/s | 4.9 |
| 2001 | 20.4°C | 17.6°C | 14.8°C | 25.2°C | 11.3°C | 31 mm | 72% | 3.3 m/s | 4.7 |
| 2000 | 21.0°C | 17.5°C | 14.0°C | 28.4°C | 10.7°C | 41 mm | 68% | 2.9 m/s | 4.9 |
| 1999 | 18.9°C | 16.4°C | 14.0°C | 22.5°C | 11.1°C | 46 mm | 76% | 3.1 m/s | 4.5 |
| 1998 | 19.8°C | 17.4°C | 15.0°C | 26.1°C | 11.1°C | 50 mm | 78% | 3.3 m/s | 4.4 |
| 1997 | 18.0°C | 15.7°C | 13.4°C | 22.7°C | 10.4°C | 102 mm | 75% | 3.2 m/s | 4.3 |
| 1996 | 18.8°C | 15.8°C | 12.7°C | 25.4°C | 10.1°C | 77 mm | 70% | 3.5 m/s | 4.8 |
| 1995 🌧️ | 17.6°C | 15.1°C | 12.6°C | 24.2°C | 9.0°C | 181 mm | 74% | 3.2 m/s | 4.2 |
| 1994 | 19.4°C | 15.7°C | 11.9°C | 24.6°C | 9.4°C | 15 mm | 61% | 3.2 m/s | 5.3 |
| 1993 | 17.7°C | 15.2°C | 12.6°C | 23.2°C | 10.0°C | 91 mm | 73% | 3.2 m/s | 4.7 |
| 1992 | 17.7°C | 14.6°C | 11.5°C | 21.5°C | 9.1°C | 30 mm | 68% | 3.3 m/s | 4.7 |
| 1991 | 18.4°C | 15.2°C | 12.0°C | 21.6°C | 8.6°C | 23 mm | 69% | 3.3 m/s | 5.1 |
| 1990 ❄️ | 16.7°C | 14.5°C | 12.2°C | 21.0°C | 9.9°C | 83 mm | 77% | 3.2 m/s | 4.3 |
| 1989 | 18.1°C | 15.2°C | 12.3°C | 22.9°C | 9.7°C | 8 mm | 72% | 3.5 m/s | 5 |
| 1988 | 18.8°C | 16.3°C | 13.8°C | 22.7°C | 11.3°C | 97 mm | 76% | 3.2 m/s | 4.6 |
| 1987 | 18.8°C | 15.4°C | 12.0°C | 25.6°C | 8.1°C | 19 mm | 73% | 2.7 m/s | 5.2 |
| 1986 | 17.9°C | 15.4°C | 13.0°C | 23.4°C | 9.8°C | 71 mm | 76% | 3.1 m/s | 4.7 |
| 1985 | 17.4°C | 15.0°C | 12.6°C | 22.7°C | 9.8°C | 86 mm | 75% | 3.2 m/s | 4.7 |
| 1984 | 17.5°C | 14.6°C | 11.7°C | 20.5°C | 9.5°C | 45 mm | 71% | 3.4 m/s | 4.8 |
| 1983 | 19.4°C | 16.1°C | 12.9°C | 26.6°C | 10.4°C | 47 mm | 70% | 2.9 m/s | — |
| 1982 | 18.4°C | 15.5°C | 12.5°C | 25.9°C | 8.1°C | 147 mm | 67% | 3.5 m/s | — |
| 1981 | 20.6°C | 16.9°C | 13.2°C | 26.2°C | 10.3°C | 7 mm | 68% | 2.8 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 19.3°C with lows near 13.4°C (mean 16.4°C), based on 45 years of NASA POWER data.
September averages 52 mm of rainfall in Sydney, one of the drier months. The wettest on record was 181 mm in 1995.
The hottest September reached 29.7°C in 2023. The coldest dipped to 8.1°C in 1982.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 1.6°C. Daytime highs moved from 18.7°C to 20.3°C and overnight lows from 12.6°C to 14.2°C over the same span.
September is one of the cooler months of the year in Sydney and one of the drier months, so plan for around 19.3°C daytime highs and 13.4°C at night.
Not quite — September is the 4th coolest month in Sydney, averaging 16.4°C.
For September in Sydney, pack light layers you can adjust through the day, with typical highs of 19.3°C and lows of 13.4°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 70% — moderately humid.
Average wind speed in September is 3.2 m/s. The windiest September on record averaged 3.5 m/s (1982).
The wettest September on record was 1995 with 181 mm. On average, September sees 52 mm.
All figures are derived from NASA POWER (Prediction Of Worldwide Energy Resources), based on MERRA-2 satellite reanalysis, covering 1981–2025.
Explore how the weather in Sydney behaves each September, based on 45 years of NASA POWER climate data from 1981 to 2025. This page breaks down average temperatures, rainfall, humidity, wind and solar radiation for September specifically, along with year-by-year records and how the month has changed over the decades.
