September is one of the cooler months of the year in Deniliquin, with average highs near 19.5°C and lows around 6.2°C (mean 12.9°C). It is about average for rainfall, averaging 33 mm of rainfall and 68% relative humidity across the period.
September is one of the cooler months of the year in Deniliquin. Across 45 years of records, the warmest September in Deniliquin was 2023 — when the month averaged 15.9°C — while the coldest was 1992 at 10.1°C. Typical September days reach 19.5°C with nights near 6.2°C. The long-term trend is warming, about 0.4°C per decade.
September is about average for rainfall in Deniliquin, averaging 33 mm of rainfall. The wettest September on record was 2016 with 88 mm, while the driest was 2017 at 5 mm.
Relative humidity in Deniliquin during September averages 68%. The most humid September was 2016 at 79%, and the least humid was 2002 at 52%.
September receives about 4.8 kWh/m²/day of solar energy in Deniliquin. The sunniest September was 2018 at 5.4 kWh/m²/day, and the cloudiest was 2016 at 4.2.
Average wind speed in Deniliquin during September is 2.4 m/s. The windiest September was 1996 at 3 m/s, while the calmest were 1995 and 1997 at 1.9 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 12.1°C | 12.2°C | 13.4°C | 13.1°C | 13.8°C | +1.7°C |
| Avg High | 18.5°C | 18.7°C | 20.4°C | 19.8°C | 20.7°C | +2.2°C |
| Avg Low | 5.7°C | 5.8°C | 6.4°C | 6.3°C | 6.8°C | +1.1°C |
| Avg Rain | 33 mm | 44 mm | 26 mm | 32 mm | 29 mm | -4 mm |
September temperatures in Deniliquin have risen by about 1.9°C between 1981–1985 and 2021–2025.
September has ranged from a record low of -0.3°C (1995) to a record high of 36°C (2017).
Rainfall in September is about average for rainfall, averaging 33 mm, with a wettest year of 88 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.6°C per decade while lows rose 0.3°C per decade, widening the gap between day and night.
A quieter season to visit Deniliquin
If your dates are flexible, the more temperate months of March and December tend to be the most comfortable for visiting Deniliquin. That said, September — with days averaging 19.5°C and nights around 6.2°C (mean 12.9°C) and moderate rainfall (33 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 | 20.6°C | 13.7°C | 6.8°C | 28.1°C | 2.4°C | 25 mm | 65% | 2.6 m/s | 4.7 |
| 2024 | 20.8°C | 13.8°C | 6.8°C | 31.6°C | 1.2°C | 31 mm | 64% | 2.7 m/s | 4.9 |
| 2023 🔥 | 23.9°C | 15.9°C | 7.9°C | 31.7°C | 1.4°C | 15 mm | 58% | 2.1 m/s | 5.2 |
| 2022 | 17.4°C | 11.8°C | 6.2°C | 21.1°C | 2.1°C | 45 mm | 79% | 2.2 m/s | 4.3 |
| 2021 | 20.7°C | 13.5°C | 6.4°C | 28.6°C | 2.5°C | 42 mm | 66% | 2.5 m/s | 5.1 |
| 2020 | 20.6°C | 13.8°C | 7.0°C | 26.3°C | 2.9°C | 17 mm | 67% | 2.4 m/s | 4.8 |
| 2019 | 20.5°C | 13.3°C | 6.2°C | 27.9°C | 2.1°C | 12 mm | 63% | 2.4 m/s | 4.9 |
| 2018 | 20.7°C | 13.1°C | 5.4°C | 28.1°C | 1.6°C | 8 mm | 56% | 2.3 m/s | 5.4 |
| 2017 | 20.7°C | 13.5°C | 6.3°C | 36.0°C | 0.9°C | 5 mm | 58% | 2.9 m/s | 4.8 |
| 2016 🌧️ | 17.1°C | 12.0°C | 6.8°C | 22.1°C | 3.5°C | 88 mm | 79% | 2.5 m/s | 4.2 |
| 2015 | 19.7°C | 12.6°C | 5.5°C | 27.4°C | 2.1°C | 20 mm | 66% | 2.1 m/s | 5.3 |
| 2014 | 20.4°C | 13.5°C | 6.6°C | 27.8°C | 2.6°C | 46 mm | 68% | 2.3 m/s | 5 |
| 2013 | 21.7°C | 15.0°C | 8.3°C | 30.4°C | 4.5°C | 32 mm | 68% | 2.4 m/s | 4.6 |
| 2012 | 20.3°C | 13.1°C | 6.0°C | 31.8°C | 0.7°C | 22 mm | 63% | 2.4 m/s | 4.9 |
| 2011 | 20.2°C | 13.3°C | 6.5°C | 29.9°C | 2.1°C | 39 mm | 65% | 2.7 m/s | 4.9 |
| 2010 | 16.9°C | 11.2°C | 5.4°C | 21.6°C | 2.2°C | 48 mm | 79% | 2.3 m/s | 4.5 |
| 2009 | 20.6°C | 13.4°C | 6.2°C | 30.5°C | 3.0°C | 35 mm | 62% | 2.7 m/s | 4.7 |
| 2008 | 21.3°C | 13.8°C | 6.2°C | 32.1°C | 1.8°C | 5 mm | 57% | 2.4 m/s | 5.3 |
| 2007 | 20.4°C | 13.1°C | 5.8°C | 25.2°C | 2.1°C | 6 mm | 60% | 2.6 m/s | 5 |
| 2006 | 21.7°C | 14.2°C | 6.8°C | 29.8°C | 2.6°C | 19 mm | 58% | 2.3 m/s | 5.3 |
| 2005 | 19.0°C | 12.5°C | 6.1°C | 24.6°C | 1.6°C | 44 mm | 71% | 2.2 m/s | 4.5 |
| 2004 | 18.9°C | 12.4°C | 6.0°C | 27.1°C | 1.8°C | 39 mm | 73% | 2 m/s | 4.5 |
| 2003 | 18.1°C | 11.7°C | 5.2°C | 30.5°C | 0.9°C | 22 mm | 73% | 2.7 m/s | 4.8 |
| 2002 | 21.4°C | 14.0°C | 6.5°C | 29.0°C | 1.2°C | 20 mm | 52% | 2.7 m/s | 4.8 |
| 2001 | 22.3°C | 15.0°C | 7.8°C | 32.5°C | 2.4°C | 29 mm | 63% | 2.4 m/s | 4.6 |
| 2000 | 20.0°C | 13.6°C | 7.1°C | 26.5°C | 2.7°C | 43 mm | 71% | 2.4 m/s | 4.6 |
| 1999 | 21.4°C | 14.6°C | 7.9°C | 27.8°C | 2.1°C | 31 mm | 67% | 2.3 m/s | 4.8 |
| 1998 | 20.3°C | 13.7°C | 7.2°C | 27.7°C | 2.3°C | 56 mm | 71% | 2.4 m/s | 4.5 |
| 1997 | 19.0°C | 12.8°C | 6.5°C | 22.9°C | 2.5°C | 52 mm | 71% | 1.9 m/s | 4.8 |
| 1996 | 17.7°C | 11.4°C | 5.1°C | 28.0°C | 0.7°C | 43 mm | 71% | 3 m/s | 4.6 |
| 1995 | 18.4°C | 11.8°C | 5.3°C | 25.0°C | -0.3°C | 9 mm | 73% | 1.9 m/s | 4.7 |
| 1994 | 18.7°C | 11.4°C | 4.2°C | 26.9°C | 1.0°C | 16 mm | 62% | 2.4 m/s | 5.1 |
| 1993 | 18.4°C | 12.3°C | 6.2°C | 27.1°C | 1.1°C | 79 mm | 75% | 2.5 m/s | 4.5 |
| 1992 ❄️ | 15.7°C | 10.1°C | 4.5°C | 21.6°C | 0.7°C | 80 mm | 77% | 2.2 m/s | 4.4 |
| 1991 | 18.1°C | 12.0°C | 5.8°C | 25.9°C | 0.8°C | 54 mm | 71% | 2.5 m/s | 4.9 |
| 1990 | 18.8°C | 12.3°C | 5.7°C | 25.9°C | 2.3°C | 17 mm | 73% | 2.3 m/s | 5 |
| 1989 | 17.6°C | 11.3°C | 5.0°C | 25.0°C | 2.0°C | 20 mm | 76% | 2.3 m/s | 5 |
| 1988 | 19.9°C | 13.2°C | 6.5°C | 27.1°C | 1.7°C | 47 mm | 71% | 2.3 m/s | 4.8 |
| 1987 | 20.0°C | 13.0°C | 6.0°C | 31.5°C | 0.6°C | 15 mm | 67% | 2.2 m/s | 5 |
| 1986 | 17.7°C | 12.0°C | 6.4°C | 22.9°C | 2.8°C | 50 mm | 76% | 2.3 m/s | 4.5 |
| 1985 | 17.6°C | 11.3°C | 4.9°C | 25.5°C | 1.6°C | 39 mm | 72% | 2.2 m/s | 5.2 |
| 1984 | 16.7°C | 10.8°C | 5.0°C | 23.6°C | 0.5°C | 31 mm | 72% | 2.5 m/s | 4.6 |
| 1983 | 17.8°C | 11.6°C | 5.4°C | 23.5°C | 0.2°C | 46 mm | 78% | 2.4 m/s | — |
| 1982 | 20.0°C | 12.7°C | 5.4°C | 28.7°C | -0.1°C | 20 mm | 53% | 2.5 m/s | — |
| 1981 | 19.3°C | 12.8°C | 6.3°C | 28.3°C | 3.5°C | 32 mm | 75% | 2.1 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 19.5°C with lows near 6.2°C (mean 12.9°C), based on 45 years of NASA POWER data.
September averages 33 mm of rainfall in Deniliquin, about average for rainfall. The wettest on record was 88 mm in 2016.
The hottest September reached 36°C in 2017. The coldest dipped to -0.3°C in 1995.
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 18.3°C to 20.7°C and overnight lows from 5.4°C to 6.8°C over the same span.
September is one of the cooler months of the year in Deniliquin and about average for rainfall, so plan for around 19.5°C daytime highs and 6.2°C at night.
Not quite — September is the 4th coolest month in Deniliquin, averaging 12.9°C.
For September in Deniliquin, pack warm layers and a jacket for chilly mornings, with typical highs of 19.5°C and lows of 6.2°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 3 m/s (1996).
The wettest September on record was 2016 with 88 mm. On average, September sees 33 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 Deniliquin 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.
