September is one of the cooler months of the year in Tumby Bay, with average highs near 16.3°C and lows around 12.3°C (mean 14.3°C). It is about average for rainfall, averaging 38 mm of rainfall and 74% relative humidity across the period.
September is one of the cooler months of the year in Tumby Bay. Across 45 years of records, the warmest September in Tumby Bay was 2023 — when the month averaged 16.4°C — while the coldest were 1984 and 1992 at 12.4°C. Typical September days reach 16.3°C with nights near 12.3°C. The long-term trend is warming, about 0.3°C per decade.
September is about average for rainfall in Tumby Bay, averaging 38 mm of rainfall. The wettest September on record was 1992 with 111 mm, while the driest was 2018 at 4 mm.
Relative humidity in Tumby Bay during September averages 74%. The most humid September was 1997 at 81%, and the least humid was 2023 at 68%.
September receives about 4.8 kWh/m²/day of solar energy in Tumby Bay. The sunniest September was 2023 at 5.4 kWh/m²/day, and the cloudiest was 2010 at 3.9.
Average wind speed in Tumby Bay during September is 5.5 m/s. The windiest September was 1996 at 6.8 m/s, while the calmest was 1987 at 4.5 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 13.9°C | 13.9°C | 14.6°C | 14.4°C | 14.9°C | +1°C |
| Avg High | 15.8°C | 15.8°C | 16.8°C | 16.5°C | 17.0°C | +1.2°C |
| Avg Low | 11.9°C | 12.0°C | 12.5°C | 12.4°C | 12.8°C | +0.9°C |
| Avg Rain | 35 mm | 57 mm | 38 mm | 33 mm | 21 mm | -15 mm |
September temperatures in Tumby Bay have risen by about 1.2°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 7.8°C (1989) to a record high of 27.3°C (2023).
Rainfall in September is about average for rainfall, averaging 38 mm, with a wettest year of 111 mm.
A quieter season to visit Tumby Bay
If your dates are flexible, the more temperate months of February and January tend to be the most comfortable for visiting Tumby Bay. That said, September — with days averaging 16.3°C and nights around 12.3°C (mean 14.3°C) and moderate rainfall (38 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 | 16.9°C | 14.8°C | 12.6°C | 23.5°C | 10.8°C | 29 mm | 72% | 5.6 m/s | 4.9 |
| 2024 | 17.0°C | 14.9°C | 12.8°C | 23.8°C | 10.8°C | 9 mm | 72% | 5.4 m/s | 4.8 |
| 2023 🔥 | 19.0°C | 16.4°C | 13.7°C | 27.3°C | 10.7°C | 7 mm | 68% | 5.1 m/s | 5.4 |
| 2022 | 15.2°C | 13.7°C | 12.2°C | 19.4°C | 10.7°C | 41 mm | 76% | 5.5 m/s | 4.3 |
| 2021 | 16.9°C | 14.7°C | 12.5°C | 23.5°C | 11.1°C | 6 mm | 71% | 5.6 m/s | 4.9 |
| 2020 | 17.1°C | 15.0°C | 12.8°C | 23.2°C | 10.1°C | 32 mm | 74% | 6.1 m/s | 4.5 |
| 2019 | 16.6°C | 14.5°C | 12.4°C | 24.9°C | 11.0°C | 15 mm | 70% | 4.9 m/s | 4.8 |
| 2018 | 16.1°C | 14.0°C | 11.8°C | 21.9°C | 10.4°C | 4 mm | 70% | 5.3 m/s | 5.1 |
| 2017 | 16.6°C | 14.7°C | 12.7°C | 23.8°C | 11.4°C | 18 mm | 71% | 6 m/s | 4.7 |
| 2016 | 15.3°C | 13.4°C | 11.5°C | 20.9°C | 9.8°C | 56 mm | 74% | 5.6 m/s | 4.2 |
| 2015 | 16.0°C | 14.1°C | 12.2°C | 24.6°C | 10.9°C | 21 mm | 73% | 4.9 m/s | 4.7 |
| 2014 | 17.2°C | 15.1°C | 13.1°C | 24.5°C | 10.8°C | 20 mm | 72% | 5.4 m/s | 5.1 |
| 2013 | 18.2°C | 16.0°C | 13.9°C | 22.7°C | 11.7°C | 46 mm | 76% | 5.5 m/s | 4.4 |
| 2012 | 16.6°C | 14.3°C | 11.9°C | 22.5°C | 9.5°C | 25 mm | 73% | 5.3 m/s | 4.9 |
| 2011 | 17.4°C | 15.1°C | 12.8°C | 22.3°C | 10.9°C | 44 mm | 71% | 5.9 m/s | 5.1 |
| 2010 | 14.5°C | 13.2°C | 11.9°C | 17.7°C | 10.8°C | 81 mm | 78% | 5.1 m/s | 3.9 |
| 2009 | 17.0°C | 14.9°C | 12.8°C | 22.7°C | 10.9°C | 66 mm | 72% | 6.1 m/s | 4.6 |
| 2008 | 17.1°C | 14.7°C | 12.2°C | 22.3°C | 10.7°C | 14 mm | 72% | 5.6 m/s | 5.3 |
| 2007 | 17.7°C | 15.1°C | 12.6°C | 23.5°C | 10.6°C | 17 mm | 70% | 6 m/s | 5 |
| 2006 | 17.6°C | 15.2°C | 12.7°C | 24.0°C | 10.9°C | 12 mm | 70% | 5.4 m/s | 4.9 |
| 2005 | 16.4°C | 14.4°C | 12.5°C | 21.4°C | 10.6°C | 70 mm | 76% | 5.3 m/s | 4.5 |
| 2004 | 15.5°C | 13.9°C | 12.2°C | 23.5°C | 9.8°C | 47 mm | 76% | 4.7 m/s | 4.5 |
| 2003 | 15.6°C | 13.7°C | 11.9°C | 22.2°C | 9.5°C | 42 mm | 75% | 6.5 m/s | 4.6 |
| 2002 | 16.6°C | 14.4°C | 12.1°C | 25.4°C | 10.4°C | 27 mm | 71% | 6.5 m/s | 4.8 |
| 2001 | 17.3°C | 15.1°C | 12.8°C | 23.7°C | 11.1°C | 51 mm | 75% | 5.7 m/s | 4.5 |
| 2000 | 16.8°C | 14.8°C | 12.8°C | 23.3°C | 11.1°C | 33 mm | 77% | 5.8 m/s | 4.7 |
| 1999 | 17.0°C | 15.0°C | 12.9°C | 23.8°C | 11.2°C | 56 mm | 74% | 5.7 m/s | 4.8 |
| 1998 | 16.7°C | 14.7°C | 12.6°C | 23.3°C | 11.1°C | 26 mm | 75% | 5.1 m/s | 4.7 |
| 1997 | 15.7°C | 14.1°C | 12.5°C | 19.2°C | 10.7°C | 66 mm | 81% | 5 m/s | 4.4 |
| 1996 | 15.7°C | 13.6°C | 11.5°C | 21.6°C | 10.1°C | 90 mm | 75% | 6.8 m/s | 4.9 |
| 1995 | 15.7°C | 13.8°C | 11.9°C | 21.0°C | 9.9°C | 72 mm | 75% | 4.8 m/s | 4.4 |
| 1994 | 15.4°C | 13.5°C | 11.7°C | 21.0°C | 10.3°C | 16 mm | 72% | 4.8 m/s | 5.1 |
| 1993 | 16.0°C | 14.1°C | 12.2°C | 22.8°C | 10.5°C | 41 mm | 74% | 4.8 m/s | 5 |
| 1992 🌧️ | 13.8°C | 12.4°C | 10.9°C | 18.6°C | 9.9°C | 111 mm | 78% | 5.3 m/s | 4.5 |
| 1991 | 16.1°C | 14.0°C | 11.8°C | 21.1°C | 10.3°C | 50 mm | 76% | 5.5 m/s | 4.7 |
| 1990 | 16.2°C | 14.1°C | 12.1°C | 22.7°C | 10.7°C | 36 mm | 75% | 5.3 m/s | 4.8 |
| 1989 | 15.5°C | 13.4°C | 11.4°C | 21.2°C | 7.8°C | 40 mm | 76% | 5.4 m/s | 5 |
| 1988 | 17.3°C | 14.9°C | 12.6°C | 23.4°C | 10.5°C | 44 mm | 70% | 5.7 m/s | 5.1 |
| 1987 | 16.2°C | 14.3°C | 12.3°C | 24.5°C | 9.7°C | 14 mm | 72% | 4.5 m/s | 4.8 |
| 1986 | 15.6°C | 13.8°C | 12.1°C | 21.8°C | 10.8°C | 35 mm | 75% | 5.7 m/s | 4.8 |
| 1985 | 15.0°C | 13.3°C | 11.5°C | 19.9°C | 10.2°C | 31 mm | 73% | 5.6 m/s | 5.1 |
| 1984 ❄️ | 13.9°C | 12.4°C | 10.8°C | 19.5°C | 9.1°C | 77 mm | 74% | 5.6 m/s | 4.4 |
| 1983 | 16.3°C | 14.1°C | 11.9°C | 23.3°C | 10.5°C | 44 mm | 76% | 5.7 m/s | — |
| 1982 | 15.4°C | 13.6°C | 11.8°C | 20.3°C | 10.3°C | 18 mm | 71% | 5.1 m/s | — |
| 1981 | 17.4°C | 15.0°C | 12.5°C | 24.0°C | 10.7°C | 16 mm | 72% | 4.9 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 16.3°C with lows near 12.3°C (mean 14.3°C), based on 45 years of NASA POWER data.
September averages 38 mm of rainfall in Tumby Bay, about average for rainfall. The wettest on record was 111 mm in 1992.
The hottest September reached 27.3°C in 2023. The coldest dipped to 7.8°C in 1989.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 1.2°C. Daytime highs moved from 15.6°C to 17°C and overnight lows from 11.7°C to 12.8°C over the same span.
September is one of the cooler months of the year in Tumby Bay and about average for rainfall, so plan for around 16.3°C daytime highs and 12.3°C at night.
Not quite — September is the 4th coolest month in Tumby Bay, averaging 14.3°C.
For September in Tumby Bay, pack light layers you can adjust through the day, with typical highs of 16.3°C and lows of 12.3°C.
Relative humidity in September averages 74% — moderately humid.
Average wind speed in September is 5.5 m/s. The windiest September on record averaged 6.8 m/s (1996).
The wettest September on record was 1992 with 111 mm. On average, September sees 38 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 Tumby Bay 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.
