September is one of the cooler months of the year in Forbes, with average highs near 19.6°C and lows around 6.1°C (mean 12.9°C). It is about average for rainfall, averaging 45 mm of rainfall and 68% relative humidity across the period.
September is one of the cooler months of the year in Forbes. Across 45 years of records, the warmest September in Forbes was 2023 — when the month averaged 16.3°C — while the coldest was 1984 at 9.8°C. Typical September days reach 19.6°C with nights near 6.1°C. The long-term trend is warming, about 0.6°C per decade.
September is about average for rainfall in Forbes, averaging 45 mm of rainfall. The wettest September on record was 2016 with 121 mm, while the driest were 2017 and 2018 at 5 mm.
Relative humidity in Forbes during September averages 68%. The most humid September was 1998 at 82%, and the least humid was 2019 at 48%.
September receives about 5 kWh/m²/day of solar energy in Forbes. The sunniest September was 2023 at 5.8 kWh/m²/day, and the cloudiest was 2016 at 3.9.
Average wind speed in Forbes during September is 2.4 m/s. The windiest Septembers were 1996 and 2009 at 2.9 m/s, while the calmest was 2004 at 1.9 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 12.0°C | 11.9°C | 13.5°C | 13.3°C | 13.9°C | +1.9°C |
| Avg High | 18.5°C | 18.1°C | 20.5°C | 20.2°C | 20.9°C | +2.4°C |
| Avg Low | 5.5°C | 5.7°C | 6.4°C | 6.3°C | 6.8°C | +1.3°C |
| Avg Rain | 44 mm | 62 mm | 42 mm | 36 mm | 34 mm | -11 mm |
September temperatures in Forbes have risen by about 1.9°C between 1981–1985 and 2021–2025.
September has ranged from a record low of -2.2°C (1982) to a record high of 34.6°C (2017).
Rainfall in September is about average for rainfall, averaging 45 mm, with a wettest year of 121 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.8°C per decade while lows rose 0.4°C per decade, widening the gap between day and night.
A quieter season to visit Forbes
If your dates are flexible, the more temperate months of March and December tend to be the most comfortable for visiting Forbes. That said, September — with days averaging 19.6°C and nights around 6.1°C (mean 12.9°C) and moderate rainfall (45 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 | 22.3°C | 14.6°C | 6.9°C | 30.8°C | 1.5°C | 27 mm | 60% | 2.6 m/s | 5.3 |
| 2024 | 21.1°C | 13.7°C | 6.3°C | 26.3°C | 1.7°C | 16 mm | 60% | 2.4 m/s | 5.3 |
| 2023 🔥 | 24.7°C | 16.3°C | 7.9°C | 33.0°C | 0.5°C | 5 mm | 51% | 2.2 m/s | 5.8 |
| 2022 | 17.3°C | 12.0°C | 6.6°C | 20.7°C | 2.3°C | 74 mm | 79% | 2.4 m/s | 4.4 |
| 2021 | 19.5°C | 12.6°C | 5.7°C | 25.6°C | 0.2°C | 46 mm | 68% | 2.6 m/s | 5.1 |
| 2020 | 20.3°C | 13.9°C | 7.5°C | 27.7°C | 1.1°C | 34 mm | 73% | 2.5 m/s | 5 |
| 2019 | 22.3°C | 14.6°C | 6.9°C | 29.0°C | -0.1°C | 7 mm | 48% | 2.7 m/s | 5.4 |
| 2018 | 21.6°C | 13.9°C | 6.1°C | 28.6°C | 0.9°C | 5 mm | 51% | 2.4 m/s | 5.3 |
| 2017 | 21.2°C | 13.5°C | 5.7°C | 34.6°C | 0.4°C | 5 mm | 51% | 2.8 m/s | 5.1 |
| 2016 🌧️ | 16.9°C | 11.9°C | 7.0°C | 21.1°C | 3.3°C | 121 mm | 80% | 2.6 m/s | 3.9 |
| 2015 | 19.8°C | 12.6°C | 5.5°C | 25.9°C | 0.6°C | 8 mm | 67% | 2.2 m/s | 5.4 |
| 2014 | 20.0°C | 13.1°C | 6.3°C | 28.8°C | 2.0°C | 29 mm | 67% | 2.4 m/s | 5.3 |
| 2013 | 21.9°C | 14.9°C | 7.8°C | 28.1°C | 3.7°C | 40 mm | 63% | 2.4 m/s | 5.4 |
| 2012 | 20.2°C | 12.7°C | 5.2°C | 28.7°C | 0.8°C | 40 mm | 63% | 2.4 m/s | 5.3 |
| 2011 | 21.0°C | 13.7°C | 6.4°C | 29.0°C | 2.5°C | 37 mm | 62% | 2.8 m/s | 5.2 |
| 2010 | 17.3°C | 11.6°C | 5.9°C | 22.0°C | 0.4°C | 67 mm | 81% | 2.2 m/s | 4.8 |
| 2009 | 21.2°C | 14.2°C | 7.2°C | 28.5°C | 2.5°C | 31 mm | 60% | 2.9 m/s | 4.8 |
| 2008 | 20.9°C | 13.4°C | 5.9°C | 28.5°C | 0.7°C | 51 mm | 62% | 2.5 m/s | 5.6 |
| 2007 | 20.8°C | 13.2°C | 5.5°C | 27.8°C | 2.0°C | 5 mm | 58% | 2.5 m/s | 5.4 |
| 2006 | 22.6°C | 14.7°C | 6.8°C | 27.8°C | 2.7°C | 14 mm | 55% | 2.4 m/s | 5.5 |
| 2005 | 18.7°C | 12.6°C | 6.5°C | 26.0°C | 1.9°C | 116 mm | 73% | 2.3 m/s | 4.8 |
| 2004 | 19.0°C | 12.5°C | 5.9°C | 29.8°C | -0.6°C | 45 mm | 71% | 1.9 m/s | 4.9 |
| 2003 | 19.3°C | 12.2°C | 5.1°C | 30.3°C | -0.4°C | 20 mm | 68% | 2.6 m/s | 5.1 |
| 2002 | 21.7°C | 13.9°C | 6.2°C | 28.2°C | 0.0°C | 55 mm | 54% | 2.7 m/s | 5.2 |
| 2001 | 20.5°C | 14.1°C | 7.6°C | 28.6°C | 2.5°C | 51 mm | 71% | 2.3 m/s | 4.5 |
| 2000 | 20.3°C | 13.7°C | 7.1°C | 29.0°C | 1.5°C | 34 mm | 73% | 2.2 m/s | 5 |
| 1999 | 20.6°C | 14.3°C | 8.0°C | 28.0°C | 1.5°C | 50 mm | 69% | 2.5 m/s | 4.9 |
| 1998 | 18.2°C | 12.8°C | 7.5°C | 26.5°C | 1.2°C | 86 mm | 82% | 2.3 m/s | 4.5 |
| 1997 | 18.7°C | 12.5°C | 6.3°C | 22.8°C | 1.5°C | 91 mm | 74% | 2.1 m/s | 4.8 |
| 1996 | 17.1°C | 10.9°C | 4.6°C | 24.9°C | -0.2°C | 73 mm | 75% | 2.9 m/s | 4.8 |
| 1995 | 19.2°C | 12.6°C | 6.0°C | 26.0°C | -1.1°C | 60 mm | 70% | 2.2 m/s | 4.6 |
| 1994 | 19.4°C | 11.6°C | 3.8°C | 26.0°C | -0.4°C | 17 mm | 56% | 2.7 m/s | 5.5 |
| 1993 | 17.3°C | 11.5°C | 5.7°C | 22.5°C | 0.4°C | 97 mm | 79% | 2.5 m/s | 4.7 |
| 1992 | 16.1°C | 10.1°C | 4.1°C | 23.9°C | -1.4°C | 58 mm | 74% | 2.3 m/s | 4.5 |
| 1991 | 17.8°C | 11.5°C | 5.1°C | 23.5°C | -1.0°C | 51 mm | 72% | 2.6 m/s | 5.2 |
| 1990 | 17.0°C | 11.2°C | 5.4°C | 23.8°C | 1.8°C | 41 mm | 81% | 2.3 m/s | 5 |
| 1989 | 17.7°C | 11.0°C | 4.4°C | 25.0°C | -0.8°C | 18 mm | 77% | 2.3 m/s | 5.1 |
| 1988 | 18.9°C | 12.7°C | 6.5°C | 22.9°C | 1.3°C | 85 mm | 75% | 2.3 m/s | 4.7 |
| 1987 | 19.2°C | 12.3°C | 5.4°C | 28.5°C | -0.5°C | 19 mm | 71% | 2.1 m/s | 5.2 |
| 1986 | 18.4°C | 12.4°C | 6.4°C | 27.5°C | 1.5°C | 53 mm | 74% | 2.3 m/s | 4.7 |
| 1985 | 17.7°C | 11.4°C | 5.1°C | 24.9°C | 0.8°C | 54 mm | 75% | 2.1 m/s | 5 |
| 1984 ❄️ | 15.5°C | 9.8°C | 4.2°C | 20.6°C | -0.9°C | 63 mm | 78% | 2.5 m/s | 4.5 |
| 1983 | 18.7°C | 12.3°C | 5.9°C | 25.6°C | 1.8°C | 61 mm | 77% | 2.5 m/s | — |
| 1982 | 20.2°C | 12.7°C | 5.1°C | 29.4°C | -2.2°C | 27 mm | 54% | 2.7 m/s | — |
| 1981 | 20.4°C | 13.3°C | 6.3°C | 29.4°C | 1.8°C | 19 mm | 72% | 2.1 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 19.6°C with lows near 6.1°C (mean 12.9°C), based on 45 years of NASA POWER data.
September averages 45 mm of rainfall in Forbes, about average for rainfall. The wettest on record was 121 mm in 2016.
The hottest September reached 34.6°C in 2017. The coldest dipped to -2.2°C in 1982.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 1.9°C. Daytime highs moved from 18.5°C to 21°C and overnight lows from 5.3°C to 6.7°C over the same span.
September is one of the cooler months of the year in Forbes and about average for rainfall, so plan for around 19.6°C daytime highs and 6.1°C at night.
Not quite — September is the 4th coolest month in Forbes, averaging 12.9°C.
For September in Forbes, pack warm layers and a jacket for chilly mornings, with typical highs of 19.6°C and lows of 6.1°C.
Relative humidity in September averages 68% — moderately humid.
Average wind speed in September is 2.4 m/s. The windiest September on record averaged 2.9 m/s (1996).
The wettest September on record was 2016 with 121 mm. On average, September sees 45 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 Forbes 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.
