September is one of the cooler months of the year in Swan Hill, with average highs near 19.9°C and lows around 6.5°C (mean 13.2°C). It is about average for rainfall, averaging 30 mm of rainfall and 66% relative humidity across the period.
September is one of the cooler months of the year in Swan Hill. Across 45 years of records, the warmest September in Swan Hill was 2023 — when the month averaged 16.5°C — while the coldest was 1992 at 10.2°C. Typical September days reach 19.9°C with nights near 6.5°C. The long-term trend is warming, about 0.5°C per decade.
September is about average for rainfall in Swan Hill, averaging 30 mm of rainfall. The wettest September on record was 1993 with 79 mm, while the driest was 2018 at 2 mm.
Relative humidity in Swan Hill during September averages 66%. The most humid September was 2010 at 79%, and the least humid was 1982 at 51%.
September receives about 4.8 kWh/m²/day of solar energy in Swan Hill. The sunniest September was 2018 at 5.3 kWh/m²/day, and the cloudiest were 2016 and 2022 at 4.2.
Average wind speed in Swan Hill during September is 2.9 m/s. The windiest September was 1996 at 3.6 m/s, while the calmest was 1997 at 2.3 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 12.4°C | 12.6°C | 13.5°C | 13.4°C | 14.5°C | +2.1°C |
| Avg High | 18.9°C | 19.0°C | 20.4°C | 20.2°C | 21.4°C | +2.5°C |
| Avg Low | 5.9°C | 6.2°C | 6.6°C | 6.7°C | 7.6°C | +1.7°C |
| Avg Rain | 31 mm | 41 mm | 27 mm | 26 mm | 19 mm | -12 mm |
September temperatures in Swan Hill have risen by about 2.3°C between 1981–1985 and 2021–2025.
September has ranged from a record low of -0.7°C (1995) to a record high of 34.2°C (2017).
Rainfall in September is about average for rainfall, averaging 30 mm, with a wettest year of 79 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.7°C per decade while lows rose 0.3°C per decade, widening the gap between day and night.
A quieter season to visit Swan Hill
If your dates are flexible, the more temperate months of March and December tend to be the most comfortable for visiting Swan Hill. That said, September — with days averaging 19.9°C and nights around 6.5°C (mean 13.2°C) and low rainfall (30 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 | 21.2°C | 14.3°C | 7.4°C | 28.5°C | 2.1°C | 14 mm | 61% | 3.2 m/s | 4.7 |
| 2024 | 21.9°C | 14.6°C | 7.3°C | 31.7°C | 1.8°C | 14 mm | 56% | 3.4 m/s | 4.9 |
| 2023 🔥 | 24.4°C | 16.5°C | 8.6°C | 32.0°C | 2.2°C | 4 mm | 52% | 2.6 m/s | 5.2 |
| 2022 | 18.7°C | 12.9°C | 7.2°C | 22.7°C | 3.3°C | 47 mm | 73% | 2.8 m/s | 4.2 |
| 2021 | 21.3°C | 14.2°C | 7.1°C | 30.6°C | 3.4°C | 26 mm | 61% | 3 m/s | 5 |
| 2020 | 21.1°C | 14.4°C | 7.7°C | 27.2°C | 2.6°C | 10 mm | 62% | 3 m/s | 4.7 |
| 2019 | 20.8°C | 13.5°C | 6.2°C | 29.4°C | 2.2°C | 11 mm | 59% | 2.9 m/s | 4.9 |
| 2018 | 20.9°C | 13.2°C | 5.6°C | 29.0°C | 2.2°C | 2 mm | 55% | 2.8 m/s | 5.3 |
| 2017 | 20.7°C | 13.8°C | 6.8°C | 34.2°C | 1.7°C | 6 mm | 57% | 3.4 m/s | 4.9 |
| 2016 | 18.4°C | 12.7°C | 7.0°C | 24.6°C | 3.0°C | 54 mm | 73% | 3 m/s | 4.2 |
| 2015 | 20.6°C | 13.3°C | 6.0°C | 29.9°C | 2.1°C | 12 mm | 62% | 2.6 m/s | 5.2 |
| 2014 | 20.9°C | 14.0°C | 7.2°C | 29.4°C | 3.1°C | 30 mm | 65% | 2.7 m/s | 5.1 |
| 2013 | 21.8°C | 15.2°C | 8.7°C | 29.1°C | 4.6°C | 42 mm | 67% | 3 m/s | 4.5 |
| 2012 | 20.5°C | 13.6°C | 6.6°C | 31.7°C | 1.7°C | 26 mm | 61% | 2.9 m/s | 4.9 |
| 2011 | 20.7°C | 13.7°C | 6.8°C | 30.2°C | 1.4°C | 35 mm | 63% | 3 m/s | 4.9 |
| 2010 | 16.8°C | 11.3°C | 5.7°C | 20.8°C | 2.2°C | 38 mm | 79% | 2.6 m/s | 4.5 |
| 2009 | 20.5°C | 13.5°C | 6.4°C | 31.9°C | 3.4°C | 43 mm | 62% | 3.2 m/s | 4.8 |
| 2008 | 21.1°C | 13.8°C | 6.5°C | 31.8°C | 2.2°C | 7 mm | 58% | 2.8 m/s | 5.2 |
| 2007 | 20.6°C | 13.4°C | 6.3°C | 26.0°C | 3.3°C | 10 mm | 59% | 3 m/s | 5.1 |
| 2006 | 21.7°C | 14.2°C | 6.8°C | 30.5°C | 2.7°C | 22 mm | 57% | 2.9 m/s | 5.2 |
| 2005 | 19.3°C | 13.0°C | 6.7°C | 25.7°C | 2.0°C | 37 mm | 69% | 2.6 m/s | 4.4 |
| 2004 | 19.0°C | 12.6°C | 6.3°C | 28.8°C | 1.9°C | 42 mm | 72% | 2.4 m/s | 4.4 |
| 2003 | 18.4°C | 12.0°C | 5.5°C | 32.3°C | 1.6°C | 20 mm | 71% | 3.3 m/s | 4.8 |
| 2002 | 21.4°C | 14.0°C | 6.6°C | 28.9°C | 1.0°C | 14 mm | 53% | 3.2 m/s | 4.8 |
| 2001 | 22.1°C | 14.9°C | 7.8°C | 33.9°C | 2.6°C | 33 mm | 63% | 2.8 m/s | 4.6 |
| 2000 | 20.1°C | 13.6°C | 7.1°C | 26.8°C | 3.3°C | 40 mm | 71% | 2.9 m/s | 4.6 |
| 1999 | 21.5°C | 14.6°C | 7.8°C | 28.1°C | 2.3°C | 29 mm | 65% | 2.8 m/s | 4.7 |
| 1998 | 20.9°C | 14.1°C | 7.3°C | 30.6°C | 2.6°C | 32 mm | 67% | 2.9 m/s | 4.6 |
| 1997 | 19.1°C | 12.9°C | 6.7°C | 22.8°C | 2.2°C | 50 mm | 70% | 2.3 m/s | 4.8 |
| 1996 | 17.9°C | 11.9°C | 5.8°C | 27.3°C | 1.0°C | 46 mm | 69% | 3.6 m/s | 4.5 |
| 1995 | 18.8°C | 12.2°C | 5.6°C | 24.9°C | -0.7°C | 12 mm | 72% | 2.4 m/s | 4.7 |
| 1994 | 18.9°C | 11.8°C | 4.6°C | 26.8°C | 0.6°C | 15 mm | 61% | 2.9 m/s | 5 |
| 1993 🌧️ | 18.7°C | 12.8°C | 6.9°C | 28.4°C | 2.0°C | 79 mm | 74% | 2.9 m/s | 4.5 |
| 1992 ❄️ | 15.7°C | 10.2°C | 4.8°C | 22.0°C | 0.8°C | 77 mm | 77% | 2.6 m/s | 4.4 |
| 1991 | 18.6°C | 12.3°C | 6.1°C | 25.9°C | 1.1°C | 58 mm | 71% | 2.9 m/s | 4.9 |
| 1990 | 19.5°C | 12.8°C | 6.1°C | 27.7°C | 3.1°C | 11 mm | 69% | 2.8 m/s | 5.1 |
| 1989 | 18.1°C | 11.8°C | 5.4°C | 26.8°C | 2.6°C | 20 mm | 74% | 2.8 m/s | 5 |
| 1988 | 20.3°C | 13.5°C | 6.7°C | 26.7°C | 1.9°C | 50 mm | 68% | 2.9 m/s | 4.8 |
| 1987 | 20.4°C | 13.4°C | 6.5°C | 32.1°C | 1.0°C | 15 mm | 67% | 2.7 m/s | 4.9 |
| 1986 | 17.9°C | 12.0°C | 6.2°C | 23.5°C | 2.3°C | 53 mm | 76% | 2.8 m/s | 4.5 |
| 1985 | 17.8°C | 11.4°C | 5.1°C | 24.0°C | 2.4°C | 31 mm | 71% | 2.7 m/s | 5.2 |
| 1984 | 17.0°C | 11.1°C | 5.1°C | 24.9°C | 1.5°C | 26 mm | 70% | 3 m/s | 4.7 |
| 1983 | 18.0°C | 11.9°C | 5.7°C | 25.4°C | 0.3°C | 50 mm | 76% | 2.8 m/s | — |
| 1982 | 20.7°C | 13.3°C | 5.9°C | 30.0°C | 0.5°C | 11 mm | 51% | 3 m/s | — |
| 1981 | 20.0°C | 13.4°C | 6.9°C | 30.0°C | 3.6°C | 26 mm | 73% | 2.5 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 19.9°C with lows near 6.5°C (mean 13.2°C), based on 45 years of NASA POWER data.
September averages 30 mm of rainfall in Swan Hill, about average for rainfall. The wettest on record was 79 mm in 1993.
The hottest September reached 34.2°C in 2017. The coldest dipped to -0.7°C in 1995.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 2.3°C. Daytime highs moved from 18.7°C to 21.5°C and overnight lows from 5.7°C to 7.5°C over the same span.
September is one of the cooler months of the year in Swan Hill and about average for rainfall, so plan for around 19.9°C daytime highs and 6.5°C at night.
Not quite — September is the 4th coolest month in Swan Hill, averaging 13.2°C.
For September in Swan Hill, pack warm layers and a jacket for chilly mornings, with typical highs of 19.9°C and lows of 6.5°C.
Relative humidity in September averages 66% — moderately humid.
Average wind speed in September is 2.9 m/s. The windiest September on record averaged 3.6 m/s (1996).
The wettest September on record was 1993 with 79 mm. On average, September sees 30 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 Swan Hill 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.
