September is one of the cooler months of the year in Mandurah, with average highs near 17.8°C and lows around 13.2°C (mean 15.5°C). It is a relatively wet time of year, averaging 83 mm of rainfall and 75% relative humidity across the period.
September is one of the cooler months of the year in Mandurah. Across 45 years of records, the warmest September in Mandurah was 2023 — when the month averaged 16.8°C — while the coldest was 2016 at 13.7°C. Typical September days reach 17.8°C with nights near 13.2°C. The long-term September temperature trend is broadly flat.
September is a relatively wet time of year in Mandurah, averaging 83 mm of rainfall. The wettest September on record was 2013 with 181 mm, while the driest was 2019 at 18 mm.
Relative humidity in Mandurah during September averages 75%. The most humid September was 1997 at 78%, and the least humid was 2010 at 70%.
September receives about 4.8 kWh/m²/day of solar energy in Mandurah. The sunniest Septembers were 2010 and 2024 at 5.4 kWh/m²/day, and the cloudiest was 2001 at 4.1.
Average wind speed in Mandurah during September is 5.3 m/s. The windiest September was 2013 at 6.4 m/s, while the calmest were 1995 and 2019 at 4.6 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 15.7°C | 15.3°C | 15.1°C | 15.5°C | 16.0°C | +0.3°C |
| Avg High | 18.1°C | 17.5°C | 17.2°C | 18.0°C | 18.5°C | +0.4°C |
| Avg Low | 13.4°C | 13.2°C | 13.1°C | 13.0°C | 13.5°C | +0.1°C |
| Avg Rain | 83 mm | 102 mm | 92 mm | 75 mm | 52 mm | -31 mm |
September temperatures in Mandurah have risen by about 0.3°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 7.9°C (2005) to a record high of 29.4°C (2023).
Rainfall in September is a relatively wet time of year, averaging 83 mm, with a wettest year of 181 mm.
A quieter season to visit Mandurah
If your dates are flexible, the more temperate months of March and December tend to be the most comfortable for visiting Mandurah. That said, September — with days averaging 17.8°C and nights around 13.2°C (mean 15.5°C) and higher rainfall (83 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 | 18.3°C | 15.8°C | 13.3°C | 24.5°C | 9.9°C | 68 mm | 75% | 4.9 m/s | 5.2 |
| 2024 | 19.1°C | 16.2°C | 13.3°C | 24.7°C | 10.8°C | 25 mm | 73% | 5.1 m/s | 5.4 |
| 2023 🔥 | 19.1°C | 16.8°C | 14.6°C | 29.4°C | 9.3°C | 57 mm | 76% | 5.3 m/s | 4.8 |
| 2022 | 17.7°C | 15.4°C | 13.1°C | 22.6°C | 10.7°C | 50 mm | 75% | 5 m/s | 4.8 |
| 2021 | 18.2°C | 15.5°C | 12.7°C | 23.2°C | 10.1°C | 53 mm | 75% | 5.1 m/s | 5.2 |
| 2020 | 18.5°C | 16.1°C | 13.7°C | 23.3°C | 10.8°C | 60 mm | 74% | 5.8 m/s | 4.7 |
| 2019 | 19.0°C | 16.3°C | 13.6°C | 23.7°C | 8.9°C | 18 mm | 75% | 4.6 m/s | 5.2 |
| 2018 | 17.2°C | 15.0°C | 12.7°C | 21.3°C | 8.4°C | 32 mm | 75% | 4.8 m/s | 4.9 |
| 2017 | 17.9°C | 15.5°C | 13.1°C | 23.8°C | 10.4°C | 59 mm | 75% | 4.7 m/s | 4.8 |
| 2016 ❄️ | 15.9°C | 13.7°C | 11.5°C | 17.6°C | 8.5°C | 60 mm | 73% | 5.2 m/s | 4.7 |
| 2015 | 18.9°C | 15.6°C | 12.3°C | 24.2°C | 9.1°C | 30 mm | 72% | 5 m/s | 5.3 |
| 2014 | 19.0°C | 16.6°C | 14.3°C | 24.7°C | 10.9°C | 98 mm | 76% | 5.1 m/s | 4.5 |
| 2013 🌧️ | 17.5°C | 15.9°C | 14.4°C | 19.6°C | 11.9°C | 181 mm | 76% | 6.4 m/s | 4.2 |
| 2012 | 17.8°C | 15.1°C | 12.4°C | 24.1°C | 9.7°C | 123 mm | 74% | 5.6 m/s | 4.9 |
| 2011 | 17.9°C | 15.6°C | 13.3°C | 20.4°C | 10.3°C | 116 mm | 74% | 5.2 m/s | 4.8 |
| 2010 | 18.8°C | 15.5°C | 12.3°C | 24.8°C | 9.7°C | 28 mm | 70% | 4.8 m/s | 5.4 |
| 2009 | 16.3°C | 14.5°C | 12.6°C | 19.0°C | 9.0°C | 141 mm | 74% | 6.3 m/s | 4.4 |
| 2008 | 17.6°C | 15.3°C | 13.1°C | 20.1°C | 9.0°C | 77 mm | 75% | 5.4 m/s | 4.7 |
| 2007 | 17.3°C | 15.6°C | 13.9°C | 21.2°C | 11.6°C | 118 mm | 75% | 5.4 m/s | 4.4 |
| 2006 | 17.8°C | 15.6°C | 13.4°C | 22.8°C | 9.2°C | 52 mm | 75% | 5.2 m/s | 4.7 |
| 2005 | 16.6°C | 14.7°C | 12.8°C | 19.7°C | 7.9°C | 116 mm | 74% | 5.9 m/s | 4.7 |
| 2004 | 16.9°C | 14.3°C | 11.7°C | 20.6°C | 8.4°C | 47 mm | 75% | 4.8 m/s | 5 |
| 2003 | 16.8°C | 14.8°C | 12.8°C | 21.8°C | 10.5°C | 113 mm | 76% | 5.9 m/s | 4.7 |
| 2002 | 16.9°C | 14.9°C | 12.8°C | 22.4°C | 9.6°C | 77 mm | 75% | 5.4 m/s | 4.8 |
| 2001 | 17.3°C | 15.3°C | 13.4°C | 21.3°C | 10.3°C | 121 mm | 75% | 5.3 m/s | 4.1 |
| 2000 | 18.0°C | 16.1°C | 14.1°C | 22.0°C | 11.2°C | 59 mm | 77% | 5 m/s | 4.5 |
| 1999 | 17.4°C | 15.1°C | 12.8°C | 20.9°C | 9.0°C | 134 mm | 76% | 5.5 m/s | 4.5 |
| 1998 | 17.4°C | 15.2°C | 13.0°C | 21.1°C | 9.4°C | 146 mm | 72% | 5.7 m/s | 4.7 |
| 1997 | 17.7°C | 15.6°C | 13.5°C | 21.5°C | 10.8°C | 122 mm | 78% | 4.8 m/s | 4.8 |
| 1996 | 17.6°C | 15.9°C | 14.3°C | 19.7°C | 11.1°C | 149 mm | 73% | 6.2 m/s | 4.5 |
| 1995 | 17.8°C | 15.9°C | 14.0°C | 20.4°C | 11.1°C | 83 mm | 75% | 4.6 m/s | 4.6 |
| 1994 | 18.5°C | 15.6°C | 12.8°C | 24.0°C | 10.0°C | 62 mm | 75% | 5.2 m/s | 5.1 |
| 1993 | 17.2°C | 15.0°C | 12.8°C | 21.1°C | 10.5°C | 108 mm | 75% | 5.1 m/s | 4.9 |
| 1992 | 15.9°C | 13.9°C | 12.0°C | 19.6°C | 9.2°C | 67 mm | 77% | 5.7 m/s | 4.7 |
| 1991 | 17.4°C | 15.6°C | 13.8°C | 20.0°C | 10.8°C | 80 mm | 75% | 5 m/s | 4.5 |
| 1990 | 18.1°C | 15.4°C | 12.7°C | 23.4°C | 9.0°C | 68 mm | 74% | 4.7 m/s | 4.6 |
| 1989 | 17.9°C | 15.9°C | 13.9°C | 21.2°C | 10.0°C | 82 mm | 73% | 5.4 m/s | 4.5 |
| 1988 | 18.3°C | 16.3°C | 14.4°C | 23.3°C | 11.5°C | 93 mm | 74% | 5.7 m/s | 4.6 |
| 1987 | 18.8°C | 15.9°C | 13.0°C | 23.8°C | 9.8°C | 39 mm | 74% | 4.9 m/s | 5.2 |
| 1986 | 17.6°C | 15.3°C | 13.1°C | 22.0°C | 10.9°C | 54 mm | 76% | 4.7 m/s | 4.4 |
| 1985 | 18.5°C | 15.5°C | 12.4°C | 23.5°C | 9.0°C | 50 mm | 74% | 5.1 m/s | 5.2 |
| 1984 | 17.8°C | 15.2°C | 12.6°C | 20.0°C | 9.3°C | 108 mm | 73% | 5.4 m/s | 5.2 |
| 1983 | 18.2°C | 16.5°C | 14.8°C | 21.8°C | 11.5°C | 103 mm | 74% | 5.4 m/s | — |
| 1982 | 18.1°C | 15.5°C | 12.8°C | 25.6°C | 8.8°C | 144 mm | 74% | 4.9 m/s | — |
| 1981 | 17.8°C | 15.5°C | 13.2°C | 22.8°C | 8.3°C | 75 mm | 76% | 5.1 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 17.8°C with lows near 13.2°C (mean 15.5°C), based on 45 years of NASA POWER data.
September averages 83 mm of rainfall in Mandurah, a relatively wet time of year. The wettest on record was 181 mm in 2013.
The hottest September reached 29.4°C in 2023. The coldest dipped to 7.9°C in 2005.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 0.3°C. Daytime highs moved from 18.1°C to 18.5°C and overnight lows from 13.2°C to 13.4°C over the same span.
September is one of the cooler months of the year in Mandurah and a relatively wet time of year, so plan for around 17.8°C daytime highs and 13.2°C at night.
Not quite — September is the 3rd coolest month in Mandurah, averaging 15.5°C.
For September in Mandurah, pack light layers you can adjust through the day, with typical highs of 17.8°C and lows of 13.2°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 75% — moderately humid.
Average wind speed in September is 5.3 m/s. The windiest September on record averaged 6.4 m/s (2013).
The wettest September on record was 2013 with 181 mm. On average, September sees 83 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 Mandurah 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.
