September is one of the cooler months of the year in Katoomba, with average highs near 15.9°C and lows around 4.7°C (mean 10.3°C). It is one of the drier months, averaging 51 mm of rainfall and 70% relative humidity across the period.
September is one of the cooler months of the year in Katoomba. Across 45 years of records, the warmest September in Katoomba was 2023 — when the month averaged 13.4°C — while the coldest was 1984 at 7.5°C. Typical September days reach 15.9°C with nights near 4.7°C. The long-term trend is warming, about 0.5°C per decade.
September is one of the drier months in Katoomba, averaging 51 mm of rainfall. The wettest September on record was 1995 with 114 mm, while the driest was 2017 at 1 mm.
Relative humidity in Katoomba during September averages 70%. The most humid September was 2022 at 83%, and the least humid was 2017 at 51%.
September receives about 4.9 kWh/m²/day of solar energy in Katoomba. The sunniest September was 2017 at 5.6 kWh/m²/day, and the cloudiest was 2022 at 4.1.
Average wind speed in Katoomba during September is 0.5 m/s. The windiest Septembers were 2002, 2009 and 2017, among others at 0.6 m/s, while the calmest were 2014, 2015 and 2022, among others at 0.4 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 9.5°C | 9.4°C | 11.0°C | 10.7°C | 11.2°C | +1.7°C |
| Avg High | 14.8°C | 14.6°C | 16.8°C | 16.6°C | 16.9°C | +2.1°C |
| Avg Low | 4.0°C | 4.2°C | 5.1°C | 4.9°C | 5.5°C | +1.5°C |
| Avg Rain | 60 mm | 69 mm | 46 mm | 40 mm | 36 mm | -24 mm |
September temperatures in Katoomba have risen by about 1.8°C between 1981–1985 and 2021–2025.
September has ranged from a record low of -2.4°C (2012) to a record high of 28.8°C (2017).
Rainfall in September is one of the drier months, averaging 51 mm, with a wettest year of 114 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.7°C per decade while lows rose 0.4°C per decade, widening the gap between day and night.
A good time to visit Katoomba
September is a good time to visit Katoomba, with days averaging 15.9°C and nights around 4.7°C (mean 10.3°C, cooler than Katoomba's yearly average) and moderate rainfall. January and February are marginally more temperate, but September still suits most travellers.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 17.2°C | 11.4°C | 5.5°C | 23.9°C | 0.4°C | 45 mm | 66% | 0.5 m/s | 5.2 |
| 2024 | 17.4°C | 11.3°C | 5.2°C | 22.5°C | -0.6°C | 25 mm | 60% | 0.5 m/s | 5 |
| 2023 🔥 | 20.6°C | 13.4°C | 6.3°C | 27.5°C | -1.0°C | 9 mm | 54% | 0.5 m/s | 5.5 |
| 2022 | 13.5°C | 9.5°C | 5.4°C | 16.0°C | 1.2°C | 85 mm | 83% | 0.4 m/s | 4.1 |
| 2021 | 16.3°C | 10.5°C | 4.7°C | 20.5°C | 0.4°C | 24 mm | 67% | 0.5 m/s | 5 |
| 2020 | 16.4°C | 11.2°C | 6.1°C | 22.6°C | 1.0°C | 26 mm | 75% | 0.5 m/s | 4.7 |
| 2019 | 17.9°C | 11.3°C | 4.8°C | 24.8°C | -0.9°C | 40 mm | 57% | 0.5 m/s | 5.1 |
| 2018 | 16.9°C | 10.7°C | 4.4°C | 24.3°C | -0.1°C | 26 mm | 62% | 0.5 m/s | 4.9 |
| 2017 | 17.8°C | 11.2°C | 4.5°C | 28.8°C | -1.2°C | 1 mm | 51% | 0.6 m/s | 5.6 |
| 2016 | 14.8°C | 9.9°C | 5.0°C | 18.0°C | 1.3°C | 71 mm | 78% | 0.5 m/s | 4.3 |
| 2015 | 15.7°C | 10.2°C | 4.6°C | 20.8°C | 0.4°C | 14 mm | 72% | 0.4 m/s | 4.8 |
| 2014 | 16.0°C | 10.5°C | 5.1°C | 24.2°C | 0.0°C | 32 mm | 72% | 0.4 m/s | 4.9 |
| 2013 | 18.5°C | 12.5°C | 6.5°C | 23.8°C | 2.6°C | 43 mm | 63% | 0.5 m/s | 5.4 |
| 2012 | 16.5°C | 10.3°C | 4.1°C | 23.9°C | -2.4°C | 39 mm | 66% | 0.5 m/s | 5.4 |
| 2011 | 16.4°C | 10.7°C | 4.9°C | 23.4°C | 0.0°C | 77 mm | 67% | 0.5 m/s | 4.8 |
| 2010 | 15.2°C | 10.0°C | 4.8°C | 19.9°C | -1.4°C | 52 mm | 77% | 0.5 m/s | 4.7 |
| 2009 | 17.3°C | 11.4°C | 5.6°C | 23.9°C | 1.1°C | 45 mm | 65% | 0.6 m/s | 5.1 |
| 2008 | 16.5°C | 10.6°C | 4.7°C | 24.0°C | -1.1°C | 66 mm | 67% | 0.5 m/s | 5.1 |
| 2007 | 15.4°C | 9.9°C | 4.3°C | 20.3°C | 0.4°C | 16 mm | 68% | 0.5 m/s | 5 |
| 2006 | 18.3°C | 12.1°C | 6.0°C | 24.5°C | 1.9°C | 49 mm | 61% | 0.5 m/s | 5 |
| 2005 | 15.7°C | 10.2°C | 4.6°C | 22.6°C | 0.4°C | 90 mm | 74% | 0.5 m/s | 4.6 |
| 2004 | 16.6°C | 10.7°C | 4.8°C | 24.4°C | -1.6°C | 45 mm | 70% | 0.4 m/s | 4.7 |
| 2003 | 16.0°C | 10.2°C | 4.4°C | 25.0°C | -1.7°C | 21 mm | 63% | 0.5 m/s | 5.3 |
| 2002 | 17.7°C | 11.4°C | 5.1°C | 23.9°C | -2.0°C | 32 mm | 54% | 0.6 m/s | 5.2 |
| 2001 | 17.2°C | 11.9°C | 6.5°C | 24.8°C | 2.6°C | 44 mm | 73% | 0.4 m/s | 4.6 |
| 2000 | 16.9°C | 11.2°C | 5.4°C | 24.8°C | -0.5°C | 51 mm | 73% | 0.5 m/s | 5 |
| 1999 | 16.0°C | 10.9°C | 5.7°C | 20.9°C | -0.1°C | 69 mm | 75% | 0.4 m/s | 4.6 |
| 1998 | 15.1°C | 10.7°C | 6.3°C | 22.9°C | -0.5°C | 59 mm | 82% | 0.4 m/s | 4.5 |
| 1997 | 14.4°C | 9.7°C | 5.0°C | 18.7°C | 1.7°C | 83 mm | 78% | 0.4 m/s | 4.3 |
| 1996 | 14.2°C | 9.2°C | 4.1°C | 21.2°C | -1.0°C | 90 mm | 72% | 0.6 m/s | 4.9 |
| 1995 🌧️ | 15.2°C | 9.6°C | 4.0°C | 21.8°C | -2.3°C | 114 mm | 73% | 0.4 m/s | 4.3 |
| 1994 | 15.7°C | 9.2°C | 2.8°C | 21.5°C | -2.1°C | 13 mm | 57% | 0.5 m/s | 5.5 |
| 1993 | 14.3°C | 9.2°C | 4.1°C | 19.5°C | -0.2°C | 93 mm | 78% | 0.5 m/s | 4.6 |
| 1992 | 13.1°C | 7.8°C | 2.6°C | 19.2°C | -2.3°C | 62 mm | 75% | 0.5 m/s | 4.6 |
| 1991 | 14.5°C | 8.9°C | 3.4°C | 19.3°C | -1.7°C | 56 mm | 71% | 0.6 m/s | 5.2 |
| 1990 | 13.7°C | 8.9°C | 4.1°C | 21.1°C | 0.6°C | 50 mm | 82% | 0.4 m/s | 4.5 |
| 1989 | 14.2°C | 8.6°C | 3.0°C | 20.3°C | -0.7°C | 22 mm | 76% | 0.5 m/s | 5.3 |
| 1988 | 14.7°C | 10.0°C | 5.2°C | 18.8°C | 1.1°C | 88 mm | 80% | 0.5 m/s | 4.5 |
| 1987 | 15.7°C | 10.0°C | 4.3°C | 23.1°C | -1.1°C | 22 mm | 71% | 0.5 m/s | 5.2 |
| 1986 | 14.4°C | 9.6°C | 4.7°C | 21.0°C | -0.1°C | 83 mm | 79% | 0.5 m/s | 4.7 |
| 1985 | 13.8°C | 8.8°C | 3.7°C | 19.6°C | -1.0°C | 80 mm | 78% | 0.4 m/s | 4.7 |
| 1984 ❄️ | 12.5°C | 7.5°C | 2.6°C | 18.1°C | -2.2°C | 62 mm | 78% | 0.5 m/s | 4.6 |
| 1983 | 15.4°C | 10.0°C | 4.6°C | 21.5°C | 0.4°C | 75 mm | 76% | 0.5 m/s | — |
| 1982 | 15.4°C | 9.4°C | 3.3°C | 24.0°C | -2.3°C | 86 mm | 64% | 0.5 m/s | — |
| 1981 | 17.5°C | 11.2°C | 4.9°C | 24.7°C | 0.0°C | 22 mm | 70% | 0.5 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 15.9°C with lows near 4.7°C (mean 10.3°C), based on 45 years of NASA POWER data.
September averages 51 mm of rainfall in Katoomba, one of the drier months. The wettest on record was 114 mm in 1995.
The hottest September reached 28.8°C in 2017. The coldest dipped to -2.4°C in 2012.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 1.8°C. Daytime highs moved from 14.9°C to 17°C and overnight lows from 3.8°C to 5.4°C over the same span.
September is one of the cooler months of the year in Katoomba and one of the drier months, so plan for around 15.9°C daytime highs and 4.7°C at night.
Not quite — September is the 5th coolest month in Katoomba, averaging 10.3°C.
For September in Katoomba, pack warm layers and a jacket for chilly mornings, with typical highs of 15.9°C and lows of 4.7°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 70% — moderately humid.
Average wind speed in September is 0.5 m/s. The windiest September on record averaged 0.6 m/s (1991).
The wettest September on record was 1995 with 114 mm. On average, September sees 51 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 Katoomba 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.
