September is one of the cooler months of the year in Cowell, with average highs near 20.1°C and lows around 8.4°C (mean 14.3°C). It is about average for rainfall, averaging 29 mm of rainfall and 66% relative humidity across the period.
September is one of the cooler months of the year in Cowell. Across 45 years of records, the warmest September in Cowell was 2023 — when the month averaged 17.3°C — while the coldest was 1992 at 11.3°C. Typical September days reach 20.1°C with nights near 8.4°C. The long-term trend is warming, about 0.4°C per decade.
September is about average for rainfall in Cowell, averaging 29 mm of rainfall. The wettest September on record was 2010 with 98 mm, while the driest was 2018 at 2 mm.
Relative humidity in Cowell during September averages 66%. The most humid September was 2010 at 81%, and the least humid was 2023 at 54%.
September receives about 5 kWh/m²/day of solar energy in Cowell. The sunniest September was 2023 at 5.6 kWh/m²/day, and the cloudiest was 2010 at 4.
Average wind speed in Cowell during September is 3.8 m/s. The windiest September was 1996 at 4.6 m/s, while the calmest was 1997 at 3.1 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 13.6°C | 13.8°C | 14.5°C | 14.3°C | 15.2°C | +1.6°C |
| Avg High | 19.4°C | 19.4°C | 20.4°C | 20.2°C | 21.3°C | +1.9°C |
| Avg Low | 7.9°C | 8.2°C | 8.5°C | 8.4°C | 9.2°C | +1.3°C |
| Avg Rain | 23 mm | 42 mm | 30 mm | 30 mm | 16 mm | -7 mm |
September temperatures in Cowell have risen by about 1.8°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 3.1°C (1995) to a record high of 33.7°C (2023).
Rainfall in September is about average for rainfall, averaging 29 mm, with a wettest year of 98 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0.5°C per decade while lows rose 0.3°C per decade, widening the gap between day and night.
A quieter season to visit Cowell
If your dates are flexible, the more temperate months of December and March tend to be the most comfortable for visiting Cowell. That said, September — with days averaging 20.1°C and nights around 8.4°C (mean 14.3°C) and low rainfall (29 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 | 21.3°C | 15.2°C | 9.2°C | 30.3°C | 6.2°C | 12 mm | 63% | 3.8 m/s | 5.2 |
| 2024 | 21.1°C | 14.8°C | 8.4°C | 32.2°C | 4.9°C | 7 mm | 62% | 3.8 m/s | 5 |
| 2023 🔥 | 24.3°C | 17.3°C | 10.3°C | 33.7°C | 5.8°C | 4 mm | 54% | 3.5 m/s | 5.6 |
| 2022 | 18.5°C | 13.5°C | 8.6°C | 23.9°C | 5.2°C | 35 mm | 72% | 3.8 m/s | 4.7 |
| 2021 | 21.2°C | 15.0°C | 8.8°C | 30.1°C | 6.3°C | 8 mm | 60% | 3.9 m/s | 5.2 |
| 2020 | 21.4°C | 15.6°C | 9.7°C | 29.6°C | 5.2°C | 33 mm | 64% | 4.2 m/s | 4.8 |
| 2019 | 21.6°C | 15.0°C | 8.3°C | 31.3°C | 5.3°C | 9 mm | 58% | 3.6 m/s | 5.2 |
| 2018 | 20.4°C | 13.9°C | 7.5°C | 28.2°C | 3.7°C | 2 mm | 58% | 3.5 m/s | 5.3 |
| 2017 | 21.2°C | 15.1°C | 8.9°C | 31.8°C | 5.5°C | 8 mm | 60% | 4.2 m/s | 5 |
| 2016 | 17.9°C | 12.5°C | 7.1°C | 25.0°C | 4.5°C | 73 mm | 70% | 4 m/s | 4.7 |
| 2015 | 19.4°C | 13.7°C | 7.9°C | 28.1°C | 5.1°C | 16 mm | 67% | 3.4 m/s | 5.1 |
| 2014 | 21.1°C | 15.1°C | 9.0°C | 30.1°C | 6.1°C | 20 mm | 65% | 3.7 m/s | 5.2 |
| 2013 | 22.3°C | 16.3°C | 10.4°C | 28.5°C | 4.7°C | 36 mm | 68% | 3.9 m/s | 4.9 |
| 2012 | 20.9°C | 14.6°C | 8.3°C | 30.0°C | 5.2°C | 13 mm | 61% | 4.1 m/s | 5 |
| 2011 | 21.3°C | 15.0°C | 8.8°C | 29.9°C | 5.1°C | 23 mm | 62% | 4 m/s | 5.2 |
| 2010 🌧️ | 16.3°C | 12.1°C | 7.8°C | 21.3°C | 4.9°C | 98 mm | 81% | 3.3 m/s | 4 |
| 2009 | 20.4°C | 14.5°C | 8.6°C | 29.7°C | 4.5°C | 51 mm | 65% | 4.3 m/s | 4.8 |
| 2008 | 21.2°C | 14.6°C | 8.0°C | 33.4°C | 5.2°C | 11 mm | 60% | 3.7 m/s | 5.4 |
| 2007 | 22.0°C | 15.4°C | 8.7°C | 32.0°C | 4.6°C | 12 mm | 57% | 4.1 m/s | 5.3 |
| 2006 | 21.7°C | 15.3°C | 8.9°C | 29.8°C | 5.1°C | 4 mm | 58% | 3.9 m/s | 5.3 |
| 2005 | 19.8°C | 14.3°C | 8.7°C | 28.1°C | 5.8°C | 64 mm | 69% | 3.7 m/s | 4.7 |
| 2004 | 19.5°C | 13.8°C | 8.1°C | 30.0°C | 5.0°C | 23 mm | 69% | 3.2 m/s | 4.7 |
| 2003 | 18.9°C | 13.5°C | 8.1°C | 28.8°C | 5.1°C | 29 mm | 68% | 4.3 m/s | 4.9 |
| 2002 | 19.8°C | 13.9°C | 8.0°C | 29.3°C | 4.3°C | 14 mm | 63% | 4.4 m/s | 4.8 |
| 2001 | 20.2°C | 14.7°C | 9.2°C | 29.7°C | 5.2°C | 69 mm | 70% | 3.9 m/s | 4.5 |
| 2000 | 20.7°C | 14.9°C | 9.1°C | 30.4°C | 5.6°C | 27 mm | 72% | 3.8 m/s | 5 |
| 1999 | 21.9°C | 15.8°C | 9.8°C | 31.3°C | 5.5°C | 29 mm | 64% | 3.9 m/s | 5 |
| 1998 | 20.9°C | 14.7°C | 8.6°C | 31.9°C | 6.0°C | 26 mm | 67% | 3.6 m/s | 5 |
| 1997 | 18.7°C | 13.7°C | 8.8°C | 22.7°C | 6.3°C | 67 mm | 74% | 3.1 m/s | 4.4 |
| 1996 | 18.5°C | 13.0°C | 7.4°C | 28.7°C | 3.8°C | 65 mm | 69% | 4.6 m/s | 4.9 |
| 1995 | 19.6°C | 13.9°C | 8.1°C | 26.6°C | 3.1°C | 33 mm | 65% | 3.4 m/s | 4.8 |
| 1994 | 18.8°C | 13.1°C | 7.5°C | 25.9°C | 4.3°C | 10 mm | 66% | 3.4 m/s | 5.3 |
| 1993 | 19.3°C | 13.9°C | 8.4°C | 29.1°C | 4.9°C | 49 mm | 67% | 3.4 m/s | 4.9 |
| 1992 ❄️ | 16.1°C | 11.3°C | 6.6°C | 22.5°C | 3.8°C | 79 mm | 76% | 3.4 m/s | 4.7 |
| 1991 | 20.2°C | 14.2°C | 8.2°C | 27.1°C | 4.6°C | 25 mm | 66% | 4 m/s | 5 |
| 1990 | 20.3°C | 14.2°C | 8.2°C | 31.4°C | 4.2°C | 34 mm | 65% | 3.7 m/s | 5.1 |
| 1989 | 18.8°C | 13.0°C | 7.3°C | 27.0°C | 4.3°C | 25 mm | 69% | 3.9 m/s | 5.2 |
| 1988 | 21.3°C | 15.2°C | 9.0°C | 30.8°C | 5.9°C | 25 mm | 57% | 4.2 m/s | 5.2 |
| 1987 | 20.2°C | 14.3°C | 8.3°C | 31.3°C | 4.8°C | 14 mm | 67% | 3.3 m/s | 5 |
| 1986 | 18.3°C | 12.8°C | 7.3°C | 26.0°C | 4.3°C | 34 mm | 72% | 3.7 m/s | 5 |
| 1985 | 17.6°C | 12.4°C | 7.2°C | 25.5°C | 4.9°C | 16 mm | 66% | 3.8 m/s | 5.2 |
| 1984 | 16.3°C | 11.4°C | 6.6°C | 23.5°C | 3.9°C | 41 mm | 71% | 4 m/s | 4.6 |
| 1983 | 20.1°C | 14.1°C | 8.0°C | 29.5°C | 4.8°C | 29 mm | 69% | 4 m/s | — |
| 1982 | 19.4°C | 13.6°C | 7.9°C | 29.1°C | 4.6°C | 18 mm | 61% | 3.6 m/s | — |
| 1981 | 22.3°C | 15.7°C | 9.2°C | 31.6°C | 6.5°C | 6 mm | 61% | 3.6 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 20.1°C with lows near 8.4°C (mean 14.3°C), based on 45 years of NASA POWER data.
September averages 29 mm of rainfall in Cowell, about average for rainfall. The wettest on record was 98 mm in 2010.
The hottest September reached 33.7°C in 2023. The coldest dipped to 3.1°C in 1995.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 1.8°C. Daytime highs moved from 19.1°C to 21.3°C and overnight lows from 7.8°C to 9.1°C over the same span.
September is one of the cooler months of the year in Cowell and about average for rainfall, so plan for around 20.1°C daytime highs and 8.4°C at night.
Not quite — September is the 4th coolest month in Cowell, averaging 14.3°C.
For September in Cowell, pack light layers you can adjust through the day, with typical highs of 20.1°C and lows of 8.4°C.
Relative humidity in September averages 66% — moderately humid.
Average wind speed in September is 3.8 m/s. The windiest September on record averaged 4.6 m/s (1996).
The wettest September on record was 2010 with 98 mm. On average, September sees 29 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 Cowell 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.
