September is one of the cooler months of the year in Streaky Bay, with average highs near 19.2°C and lows around 10.9°C (mean 15.1°C). It is about average for rainfall, averaging 27 mm of rainfall and 67% relative humidity across the period.
September is one of the cooler months of the year in Streaky Bay. Across 45 years of records, the warmest September in Streaky Bay was 2023 — when the month averaged 17.9°C — while the coldest was 1984 at 12.7°C. Typical September days reach 19.2°C with nights near 10.9°C. The long-term trend is warming, about 0.3°C per decade.
September is about average for rainfall in Streaky Bay, averaging 27 mm of rainfall. The wettest September on record was 1992 with 87 mm, while the driest were 2018 and 2021 at 2 mm.
Relative humidity in Streaky Bay during September averages 67%. The most humid September was 2010 at 78%, and the least humid was 2023 at 57%.
September receives about 5.2 kWh/m²/day of solar energy in Streaky Bay. The sunniest September was 2023 at 5.7 kWh/m²/day, and the cloudiest was 2010 at 4.3.
Average wind speed in Streaky Bay during September is 4.2 m/s. The windiest Septembers were 1996 and 2002 at 4.9 m/s, while the calmest was 1987 at 3.6 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 14.6°C | 14.7°C | 15.3°C | 15.2°C | 15.9°C | +1.3°C |
| Avg High | 18.7°C | 18.8°C | 19.5°C | 19.4°C | 20.3°C | +1.6°C |
| Avg Low | 10.4°C | 10.7°C | 11.1°C | 11.0°C | 11.6°C | +1.2°C |
| Avg Rain | 25 mm | 45 mm | 31 mm | 19 mm | 10 mm | -15 mm |
September temperatures in Streaky Bay have risen by about 1.5°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 5.4°C (1995) to a record high of 32.1°C (2023).
Rainfall in September is about average for rainfall, averaging 27 mm, with a wettest year of 87 mm.
A quieter season to visit Streaky Bay
If your dates are flexible, the more temperate months of January and February tend to be the most comfortable for visiting Streaky Bay. That said, September — with days averaging 19.2°C and nights around 10.9°C (mean 15.1°C) and low rainfall (27 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 | 19.5°C | 15.6°C | 11.6°C | 30.1°C | 7.8°C | 3 mm | 66% | 4.1 m/s | 5.4 |
| 2024 | 19.7°C | 15.4°C | 11.1°C | 26.9°C | 6.5°C | 4 mm | 65% | 4.2 m/s | 5.1 |
| 2023 🔥 | 23.3°C | 17.9°C | 12.4°C | 32.1°C | 7.2°C | 2 mm | 57% | 4.1 m/s | 5.7 |
| 2022 | 18.5°C | 14.7°C | 10.8°C | 24.8°C | 7.2°C | 26 mm | 70% | 4.4 m/s | 5 |
| 2021 | 20.1°C | 15.8°C | 11.4°C | 27.5°C | 8.6°C | 2 mm | 63% | 4.3 m/s | 5.4 |
| 2020 | 20.5°C | 16.3°C | 12.1°C | 28.9°C | 7.7°C | 24 mm | 67% | 4.7 m/s | 5 |
| 2019 | 20.7°C | 15.9°C | 11.2°C | 29.7°C | 6.7°C | 12 mm | 60% | 3.9 m/s | 5.4 |
| 2018 | 19.6°C | 14.8°C | 10.1°C | 25.6°C | 6.8°C | 2 mm | 60% | 4.1 m/s | 5.6 |
| 2017 | 19.4°C | 15.7°C | 11.9°C | 27.3°C | 9.6°C | 3 mm | 64% | 4.3 m/s | 5.2 |
| 2016 | 17.6°C | 13.7°C | 9.9°C | 25.4°C | 6.7°C | 20 mm | 67% | 4.3 m/s | 4.9 |
| 2015 | 19.6°C | 15.1°C | 10.6°C | 28.2°C | 7.7°C | 11 mm | 66% | 4 m/s | 5.4 |
| 2014 | 19.9°C | 15.6°C | 11.2°C | 28.6°C | 7.3°C | 12 mm | 66% | 4.1 m/s | 5.5 |
| 2013 | 21.0°C | 16.9°C | 12.9°C | 29.0°C | 9.3°C | 21 mm | 69% | 4.3 m/s | 5.2 |
| 2012 | 19.8°C | 15.3°C | 10.7°C | 26.6°C | 6.2°C | 16 mm | 65% | 4.3 m/s | 5.3 |
| 2011 | 19.7°C | 15.6°C | 11.5°C | 26.1°C | 8.3°C | 41 mm | 67% | 4.4 m/s | 5.4 |
| 2010 | 16.5°C | 13.4°C | 10.3°C | 21.2°C | 6.9°C | 47 mm | 78% | 4 m/s | 4.3 |
| 2009 | 19.1°C | 15.3°C | 11.5°C | 25.9°C | 8.8°C | 50 mm | 68% | 4.7 m/s | 5.1 |
| 2008 | 20.2°C | 15.4°C | 10.7°C | 26.9°C | 7.1°C | 8 mm | 66% | 4 m/s | 5.6 |
| 2007 | 20.8°C | 15.9°C | 11.1°C | 27.5°C | 7.3°C | 11 mm | 62% | 4.3 m/s | 5.5 |
| 2006 | 20.6°C | 15.9°C | 11.3°C | 28.3°C | 7.0°C | 3 mm | 62% | 4.2 m/s | 5.4 |
| 2005 | 18.5°C | 14.7°C | 11.0°C | 24.7°C | 8.7°C | 72 mm | 71% | 4.3 m/s | 4.7 |
| 2004 | 18.5°C | 14.5°C | 10.5°C | 27.6°C | 6.7°C | 46 mm | 71% | 3.7 m/s | 4.8 |
| 2003 | 18.3°C | 14.7°C | 11.1°C | 28.3°C | 8.0°C | 27 mm | 71% | 4.5 m/s | 5.1 |
| 2002 | 18.7°C | 14.7°C | 10.6°C | 27.4°C | 6.2°C | 16 mm | 68% | 4.9 m/s | 5.1 |
| 2001 | 20.4°C | 16.2°C | 11.9°C | 30.2°C | 7.2°C | 46 mm | 69% | 4.5 m/s | 5.2 |
| 2000 | 19.5°C | 15.6°C | 11.7°C | 28.9°C | 8.0°C | 26 mm | 73% | 4.2 m/s | 5.2 |
| 1999 | 20.8°C | 16.3°C | 11.7°C | 30.4°C | 7.5°C | 53 mm | 66% | 4.4 m/s | 5.1 |
| 1998 | 19.9°C | 15.5°C | 11.1°C | 31.3°C | 7.6°C | 23 mm | 68% | 3.7 m/s | 5.2 |
| 1997 | 18.7°C | 15.0°C | 11.3°C | 25.2°C | 9.3°C | 66 mm | 75% | 3.8 m/s | 4.6 |
| 1996 | 18.2°C | 14.6°C | 10.9°C | 24.6°C | 7.3°C | 61 mm | 70% | 4.9 m/s | 5.2 |
| 1995 | 18.8°C | 14.6°C | 10.4°C | 25.8°C | 5.4°C | 25 mm | 68% | 3.9 m/s | 5 |
| 1994 | 17.8°C | 13.9°C | 10.0°C | 24.5°C | 5.7°C | 14 mm | 69% | 3.7 m/s | 5.5 |
| 1993 | 19.3°C | 14.9°C | 10.6°C | 27.3°C | 7.9°C | 34 mm | 66% | 3.8 m/s | 5.3 |
| 1992 🌧️ | 16.2°C | 13.0°C | 9.7°C | 23.1°C | 6.2°C | 87 mm | 76% | 4.1 m/s | 4.9 |
| 1991 | 18.6°C | 14.7°C | 10.8°C | 26.2°C | 8.2°C | 53 mm | 70% | 4.3 m/s | 5.3 |
| 1990 | 19.2°C | 14.8°C | 10.5°C | 28.7°C | 7.9°C | 38 mm | 67% | 3.9 m/s | 5.5 |
| 1989 | 18.1°C | 14.1°C | 10.0°C | 25.5°C | 6.8°C | 27 mm | 70% | 4.3 m/s | 5.4 |
| 1988 | 20.5°C | 16.1°C | 11.6°C | 28.6°C | 8.2°C | 28 mm | 63% | 4.5 m/s | 5.4 |
| 1987 | 19.3°C | 14.9°C | 10.5°C | 29.5°C | 6.6°C | 10 mm | 69% | 3.6 m/s | 5.1 |
| 1986 | 18.0°C | 14.1°C | 10.1°C | 23.6°C | 6.5°C | 36 mm | 71% | 4.2 m/s | 5.1 |
| 1985 | 18.2°C | 13.9°C | 9.7°C | 24.9°C | 6.6°C | 19 mm | 65% | 4.5 m/s | 5.6 |
| 1984 ❄️ | 16.1°C | 12.7°C | 9.2°C | 23.4°C | 6.4°C | 48 mm | 71% | 4.2 m/s | 4.9 |
| 1983 | 19.1°C | 15.0°C | 10.8°C | 28.3°C | 7.5°C | 26 mm | 71% | 4.3 m/s | — |
| 1982 | 18.6°C | 14.5°C | 10.4°C | 26.8°C | 6.8°C | 23 mm | 64% | 3.8 m/s | — |
| 1981 | 20.5°C | 15.9°C | 11.3°C | 29.5°C | 6.5°C | 4 mm | 66% | 3.7 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 19.2°C with lows near 10.9°C (mean 15.1°C), based on 45 years of NASA POWER data.
September averages 27 mm of rainfall in Streaky Bay, about average for rainfall. The wettest on record was 87 mm in 1992.
The hottest September reached 32.1°C in 2023. The coldest dipped to 5.4°C in 1995.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 1.5°C. Daytime highs moved from 18.5°C to 20.2°C and overnight lows from 10.3°C to 11.5°C over the same span.
September is one of the cooler months of the year in Streaky Bay and about average for rainfall, so plan for around 19.2°C daytime highs and 10.9°C at night.
Not quite — September is the 4th coolest month in Streaky Bay, averaging 15.1°C.
For September in Streaky Bay, pack light layers you can adjust through the day, with typical highs of 19.2°C and lows of 10.9°C.
Relative humidity in September averages 67% — moderately humid.
Average wind speed in September is 4.2 m/s. The windiest September on record averaged 4.9 m/s (1996).
The wettest September on record was 1992 with 87 mm. On average, September sees 27 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 Streaky 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.
