September is one of the cooler months of the year in Gunnedah, with average highs near 22.3°C and lows around 7.4°C (mean 14.9°C). It is one of the drier months, averaging 40 mm of rainfall and 62% relative humidity across the period.
September is one of the cooler months of the year in Gunnedah. Across 45 years of records, the warmest September in Gunnedah was 2023 — when the month averaged 18.1°C — while the coldest was 1984 at 11.9°C. Typical September days reach 22.3°C with nights near 7.4°C. The long-term trend is warming, about 0.5°C per decade.
September is one of the drier months in Gunnedah, averaging 40 mm of rainfall. The wettest September on record was 1998 with 123 mm, while the driest was 2007 at 2 mm.
Relative humidity in Gunnedah during September averages 62%. The most humid September was 1998 at 81%, and the least humid was 2019 at 39%.
September receives about 5.5 kWh/m²/day of solar energy in Gunnedah. The sunniest Septembers were 2003 and 2013 at 6.1 kWh/m²/day, and the cloudiest was 2016 at 4.4.
Average wind speed in Gunnedah during September is 2 m/s. The windiest Septembers were 1996, 2017 and 2019, among others at 2.2 m/s, while the calmest was 1987 at 1.5 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 14.0°C | 13.9°C | 15.6°C | 15.3°C | 15.7°C | +1.7°C |
| Avg High | 21.4°C | 21.1°C | 23.4°C | 22.8°C | 23.3°C | +1.9°C |
| Avg Low | 6.7°C | 6.8°C | 7.9°C | 7.7°C | 8.1°C | +1.4°C |
| Avg Rain | 38 mm | 51 mm | 35 mm | 36 mm | 36 mm | -1 mm |
September temperatures in Gunnedah have risen by about 1.5°C between 1981–1985 and 2021–2025.
September has ranged from a record low of -1°C (1987) to a record high of 34.8°C (2000).
Rainfall in September is one of the drier months, averaging 40 mm, with a wettest year of 123 mm.
A good time to visit Gunnedah
September is a good time to visit Gunnedah, with days averaging 22.3°C and nights around 7.4°C (mean 14.9°C, cooler than Gunnedah's yearly average) and moderate rainfall. November and March 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 | 23.2°C | 15.6°C | 8.0°C | 31.1°C | 4.2°C | 29 mm | 61% | 1.9 m/s | 5.5 |
| 2024 | 24.0°C | 16.0°C | 8.0°C | 29.3°C | 2.4°C | 25 mm | 57% | 2.1 m/s | 5.6 |
| 2023 🔥 | 26.9°C | 18.1°C | 9.2°C | 33.1°C | 1.9°C | 4 mm | 44% | 1.8 m/s | 6 |
| 2022 | 19.9°C | 14.0°C | 8.2°C | 24.1°C | 4.7°C | 97 mm | 74% | 2 m/s | 4.8 |
| 2021 | 21.8°C | 14.3°C | 6.9°C | 26.9°C | 1.5°C | 38 mm | 65% | 2 m/s | 5.6 |
| 2020 | 23.8°C | 16.2°C | 8.5°C | 28.7°C | 2.9°C | 25 mm | 62% | 2 m/s | 5.5 |
| 2019 | 25.4°C | 16.9°C | 8.5°C | 32.3°C | 1.8°C | 5 mm | 39% | 2.2 m/s | 6 |
| 2018 | 23.1°C | 15.4°C | 7.6°C | 30.7°C | 2.4°C | 28 mm | 57% | 2.1 m/s | 5.4 |
| 2017 | 24.7°C | 16.4°C | 8.0°C | 34.4°C | 2.4°C | 3 mm | 42% | 2.2 m/s | 5.8 |
| 2016 | 19.4°C | 13.4°C | 7.4°C | 22.3°C | 3.0°C | 90 mm | 76% | 2 m/s | 4.4 |
| 2015 | 21.8°C | 14.3°C | 6.9°C | 27.8°C | 2.3°C | 17 mm | 63% | 1.9 m/s | 5.7 |
| 2014 | 22.1°C | 14.7°C | 7.3°C | 30.7°C | 2.6°C | 20 mm | 63% | 1.9 m/s | 5.8 |
| 2013 | 25.8°C | 17.6°C | 9.3°C | 32.0°C | 4.4°C | 28 mm | 54% | 1.9 m/s | 6.1 |
| 2012 | 23.2°C | 15.0°C | 6.9°C | 29.9°C | 1.2°C | 26 mm | 57% | 1.9 m/s | 5.8 |
| 2011 | 23.0°C | 15.2°C | 7.3°C | 29.2°C | 2.0°C | 89 mm | 59% | 2.1 m/s | 5.3 |
| 2010 | 19.9°C | 14.0°C | 8.1°C | 24.5°C | 1.8°C | 58 mm | 76% | 1.7 m/s | 4.7 |
| 2009 | 23.5°C | 16.1°C | 8.7°C | 29.6°C | 2.9°C | 65 mm | 57% | 2.1 m/s | 5.4 |
| 2008 | 22.9°C | 15.5°C | 8.1°C | 31.4°C | 3.0°C | 40 mm | 63% | 2.1 m/s | 5.3 |
| 2007 | 23.0°C | 15.3°C | 7.5°C | 30.8°C | 3.8°C | 2 mm | 57% | 2.1 m/s | 5.9 |
| 2006 | 24.4°C | 16.3°C | 8.3°C | 32.2°C | 4.1°C | 34 mm | 59% | 2.1 m/s | 5.6 |
| 2005 | 21.5°C | 14.5°C | 7.6°C | 28.2°C | 2.7°C | 82 mm | 68% | 1.8 m/s | 5.2 |
| 2004 | 22.1°C | 14.6°C | 7.2°C | 32.4°C | -0.4°C | 45 mm | 64% | 1.7 m/s | 5.6 |
| 2003 | 23.5°C | 15.3°C | 7.2°C | 32.6°C | 1.8°C | 7 mm | 53% | 2.1 m/s | 6.1 |
| 2002 | 24.3°C | 16.2°C | 8.0°C | 31.5°C | 2.2°C | 35 mm | 50% | 2.1 m/s | 5.3 |
| 2001 | 23.1°C | 15.4°C | 7.8°C | 29.4°C | 4.5°C | 28 mm | 63% | 1.8 m/s | 5.2 |
| 2000 | 25.3°C | 17.2°C | 9.0°C | 34.8°C | 2.5°C | 10 mm | 57% | 2 m/s | 5.5 |
| 1999 | 22.7°C | 15.6°C | 8.5°C | 29.9°C | 2.2°C | 40 mm | 64% | 1.8 m/s | 5.4 |
| 1998 🌧️ | 20.3°C | 14.5°C | 8.6°C | 27.8°C | 2.3°C | 123 mm | 81% | 1.7 m/s | 4.9 |
| 1997 | 21.7°C | 14.6°C | 7.6°C | 27.2°C | 3.4°C | 95 mm | 67% | 1.9 m/s | 5.2 |
| 1996 | 21.0°C | 13.7°C | 6.4°C | 29.2°C | 1.8°C | 38 mm | 65% | 2.2 m/s | 5.3 |
| 1995 | 21.6°C | 14.4°C | 7.3°C | 27.2°C | -0.5°C | 71 mm | 64% | 1.8 m/s | 5.1 |
| 1994 | 22.7°C | 14.1°C | 5.5°C | 26.2°C | 1.4°C | 5 mm | 43% | 2.1 m/s | 5.9 |
| 1993 | 19.7°C | 12.8°C | 5.9°C | 26.2°C | 2.4°C | 66 mm | 71% | 1.9 m/s | 5.3 |
| 1992 | 20.4°C | 12.8°C | 5.2°C | 27.9°C | 1.0°C | 24 mm | 60% | 2 m/s | 5.3 |
| 1991 | 21.7°C | 13.9°C | 6.2°C | 26.2°C | -0.1°C | 23 mm | 57% | 2.2 m/s | 5.7 |
| 1990 | 19.4°C | 12.8°C | 6.3°C | 26.1°C | 2.1°C | 26 mm | 75% | 1.9 m/s | 5.4 |
| 1989 | 20.6°C | 12.8°C | 5.0°C | 29.0°C | 0.7°C | 3 mm | 67% | 1.9 m/s | 5.9 |
| 1988 | 21.3°C | 14.7°C | 8.1°C | 28.2°C | 2.4°C | 75 mm | 72% | 2.2 m/s | 4.9 |
| 1987 | 21.6°C | 13.9°C | 6.2°C | 28.3°C | -1.0°C | 14 mm | 62% | 1.5 m/s | 5.8 |
| 1986 | 21.6°C | 14.4°C | 7.2°C | 29.2°C | 1.9°C | 68 mm | 67% | 1.8 m/s | 5.2 |
| 1985 | 19.9°C | 13.0°C | 6.1°C | 25.9°C | 0.2°C | 30 mm | 68% | 1.8 m/s | 5.5 |
| 1984 ❄️ | 18.9°C | 11.9°C | 4.8°C | 23.8°C | 0.3°C | 41 mm | 66% | 2.1 m/s | 5.3 |
| 1983 | 21.1°C | 14.5°C | 7.9°C | 27.9°C | 3.8°C | 62 mm | 75% | 2.1 m/s | — |
| 1982 | 22.9°C | 15.0°C | 7.1°C | 30.0°C | 1.6°C | 18 mm | 48% | 2.2 m/s | — |
| 1981 | 24.3°C | 16.1°C | 7.9°C | 31.5°C | 0.3°C | 26 mm | 58% | 1.7 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 22.3°C with lows near 7.4°C (mean 14.9°C), based on 45 years of NASA POWER data.
September averages 40 mm of rainfall in Gunnedah, one of the drier months. The wettest on record was 123 mm in 1998.
The hottest September reached 34.8°C in 2000. The coldest dipped to -1°C in 1987.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 1.5°C. Daytime highs moved from 21.4°C to 23.2°C and overnight lows from 6.8°C to 8.1°C over the same span.
September is one of the cooler months of the year in Gunnedah and one of the drier months, so plan for around 22.3°C daytime highs and 7.4°C at night.
Not quite — September is the 5th coolest month in Gunnedah, averaging 14.9°C.
For September in Gunnedah, pack warm layers and a jacket for chilly mornings, with typical highs of 22.3°C and lows of 7.4°C.
Relative humidity in September averages 62% — moderately humid.
Average wind speed in September is 2 m/s. The windiest September on record averaged 2.2 m/s (1982).
The wettest September on record was 1998 with 123 mm. On average, September sees 40 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 Gunnedah 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.
