September is one of the cooler months of the year in Geraldton, with average highs near 19.5°C and lows around 16.5°C (mean 18°C). It is about average for rainfall, averaging 34 mm of rainfall and 71% relative humidity across the period.
September is one of the cooler months of the year in Geraldton. Across 45 years of records, the warmest September in Geraldton was 2014 — when the month averaged 19.2°C — while the coldest was 2016 at 16.5°C. Typical September days reach 19.5°C with nights near 16.5°C. The long-term September temperature trend is broadly flat.
September is about average for rainfall in Geraldton, averaging 34 mm of rainfall. The wettest September on record was 2014 with 79 mm, while the driest was 2019 at 5 mm.
Relative humidity in Geraldton during September averages 71%. The most humid September was 2023 at 75%, and the least humid was 1984 at 67%.
September receives about 5.7 kWh/m²/day of solar energy in Geraldton. The sunniest September was 2019 at 6.3 kWh/m²/day, and the cloudiest was 2014 at 5.2.
Average wind speed in Geraldton during September is 5.7 m/s. The windiest September was 2024 at 6.4 m/s, while the calmest was 1986 at 4.9 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 18.2°C | 17.8°C | 17.6°C | 18.1°C | 18.5°C | +0.3°C |
| Avg High | 19.7°C | 19.2°C | 19.0°C | 19.7°C | 20.2°C | +0.5°C |
| Avg Low | 16.7°C | 16.4°C | 16.2°C | 16.5°C | 16.8°C | +0.1°C |
| Avg Rain | 34 mm | 43 mm | 39 mm | 30 mm | 18 mm | -16 mm |
September temperatures in Geraldton have risen by about 0.4°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 11.8°C (2004) to a record high of 27.8°C (2015).
Rainfall in September is about average for rainfall, averaging 34 mm, with a wettest year of 79 mm.
A quieter season to visit Geraldton
If your dates are flexible, the more temperate months of December and April tend to be the most comfortable for visiting Geraldton. That said, September — with days averaging 19.5°C and nights around 16.5°C (mean 18°C) and moderate rainfall (34 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 | 20.0°C | 18.2°C | 16.4°C | 26.6°C | 13.9°C | 33 mm | 70% | 5.9 m/s | 6 |
| 2024 | 21.1°C | 19.1°C | 17.2°C | 24.7°C | 15.4°C | 8 mm | 70% | 6.4 m/s | 6.1 |
| 2023 | 20.3°C | 18.9°C | 17.6°C | 27.3°C | 14.9°C | 12 mm | 75% | 5.5 m/s | 5.8 |
| 2022 | 19.7°C | 18.2°C | 16.6°C | 24.0°C | 14.4°C | 38 mm | 71% | 5.6 m/s | 5.4 |
| 2021 | 20.1°C | 18.3°C | 16.4°C | 24.6°C | 14.0°C | 11 mm | 69% | 5.7 m/s | 6.1 |
| 2020 | 20.0°C | 18.4°C | 16.9°C | 25.5°C | 15.4°C | 8 mm | 70% | 5.5 m/s | 5.8 |
| 2019 | 20.2°C | 18.6°C | 16.9°C | 23.9°C | 14.8°C | 5 mm | 73% | 5.3 m/s | 6.3 |
| 2018 | 19.2°C | 17.6°C | 16.1°C | 23.6°C | 14.0°C | 10 mm | 71% | 5.6 m/s | 6 |
| 2017 | 19.5°C | 18.0°C | 16.5°C | 22.5°C | 14.1°C | 46 mm | 73% | 5.6 m/s | 5.4 |
| 2016 ❄️ | 18.0°C | 16.5°C | 15.1°C | 20.2°C | 13.4°C | 13 mm | 69% | 5.9 m/s | 6 |
| 2015 | 20.6°C | 18.4°C | 16.3°C | 27.8°C | 13.9°C | 10 mm | 69% | 5.5 m/s | 6.2 |
| 2014 🔥 🌧️ | 20.6°C | 19.2°C | 17.8°C | 23.7°C | 15.8°C | 79 mm | 73% | 5.7 m/s | 5.2 |
| 2013 | 19.2°C | 18.2°C | 17.2°C | 21.7°C | 15.6°C | 52 mm | 72% | 6.1 m/s | 5.3 |
| 2012 | 19.8°C | 18.2°C | 16.6°C | 25.2°C | 14.5°C | 36 mm | 71% | 6.2 m/s | 5.6 |
| 2011 | 19.8°C | 18.3°C | 16.8°C | 22.0°C | 14.3°C | 40 mm | 69% | 5.4 m/s | 5.7 |
| 2010 | 20.4°C | 18.3°C | 16.1°C | 26.8°C | 14.4°C | 13 mm | 68% | 5.6 m/s | 6 |
| 2009 | 18.3°C | 17.0°C | 15.8°C | 22.0°C | 13.5°C | 48 mm | 70% | 5.6 m/s | 5.7 |
| 2008 | 19.6°C | 18.0°C | 16.5°C | 23.1°C | 12.3°C | 42 mm | 71% | 5.8 m/s | 5.4 |
| 2007 | 19.3°C | 18.0°C | 16.6°C | 22.3°C | 14.9°C | 26 mm | 71% | 5.5 m/s | 5.7 |
| 2006 | 20.0°C | 18.3°C | 16.6°C | 23.5°C | 12.6°C | 16 mm | 72% | 6 m/s | 5.6 |
| 2005 | 18.3°C | 17.1°C | 15.8°C | 21.6°C | 13.3°C | 50 mm | 72% | 6.1 m/s | 5.6 |
| 2004 | 18.5°C | 17.0°C | 15.6°C | 21.6°C | 11.8°C | 40 mm | 71% | 5.8 m/s | 5.4 |
| 2003 | 18.3°C | 17.0°C | 15.8°C | 24.6°C | 14.5°C | 58 mm | 73% | 5.8 m/s | 5.4 |
| 2002 | 18.9°C | 17.4°C | 15.8°C | 24.2°C | 12.9°C | 30 mm | 70% | 6.2 m/s | 5.7 |
| 2001 | 18.8°C | 17.5°C | 16.2°C | 23.5°C | 14.4°C | 55 mm | 72% | 5.5 m/s | 5.4 |
| 2000 | 19.7°C | 18.3°C | 16.9°C | 24.6°C | 15.3°C | 24 mm | 73% | 5.5 m/s | 5.6 |
| 1999 | 19.2°C | 17.6°C | 16.1°C | 22.8°C | 13.6°C | 59 mm | 73% | 5.9 m/s | 5.3 |
| 1998 | 19.3°C | 17.8°C | 16.3°C | 22.1°C | 13.6°C | 48 mm | 69% | 6.3 m/s | 5.6 |
| 1997 | 18.7°C | 17.5°C | 16.4°C | 21.1°C | 14.7°C | 59 mm | 75% | 5.4 m/s | 5.7 |
| 1996 | 19.3°C | 18.2°C | 17.1°C | 21.4°C | 15.0°C | 40 mm | 71% | 6 m/s | 5.3 |
| 1995 | 19.4°C | 18.2°C | 17.0°C | 22.2°C | 15.1°C | 41 mm | 72% | 5.6 m/s | 5.6 |
| 1994 | 20.4°C | 18.7°C | 16.9°C | 25.5°C | 14.4°C | 21 mm | 71% | 5.9 m/s | 5.9 |
| 1993 | 18.9°C | 17.4°C | 15.8°C | 22.5°C | 13.9°C | 45 mm | 70% | 5.2 m/s | 5.8 |
| 1992 | 18.3°C | 17.2°C | 16.0°C | 21.5°C | 14.4°C | 48 mm | 72% | 5.9 m/s | 5.4 |
| 1991 | 18.9°C | 17.8°C | 16.6°C | 20.6°C | 14.8°C | 30 mm | 71% | 5.4 m/s | 5.5 |
| 1990 | 19.7°C | 17.7°C | 15.7°C | 26.7°C | 13.6°C | 34 mm | 70% | 5.3 m/s | 5.6 |
| 1989 | 19.7°C | 18.5°C | 17.3°C | 24.1°C | 15.2°C | 21 mm | 69% | 5.2 m/s | 5.6 |
| 1988 | 19.8°C | 18.4°C | 17.1°C | 24.3°C | 15.1°C | 20 mm | 71% | 5.3 m/s | 5.4 |
| 1987 | 20.8°C | 18.7°C | 16.7°C | 26.8°C | 14.6°C | 11 mm | 69% | 5.7 m/s | 5.9 |
| 1986 | 18.7°C | 17.5°C | 16.3°C | 23.0°C | 14.4°C | 39 mm | 73% | 4.9 m/s | 5.3 |
| 1985 | 19.9°C | 18.3°C | 16.7°C | 26.1°C | 14.6°C | 55 mm | 72% | 5.8 m/s | 5.8 |
| 1984 | 19.8°C | 18.1°C | 16.4°C | 23.4°C | 14.5°C | 45 mm | 67% | 5.6 m/s | 5.8 |
| 1983 | 19.8°C | 18.5°C | 17.1°C | 23.6°C | 15.4°C | 47 mm | 74% | 5.9 m/s | — |
| 1982 | 19.2°C | 17.6°C | 15.9°C | 24.2°C | 13.4°C | 54 mm | 72% | 6 m/s | — |
| 1981 | 19.5°C | 18.1°C | 16.8°C | 22.6°C | 14.0°C | 16 mm | 74% | 5.1 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 16.5°C (mean 18°C), based on 45 years of NASA POWER data.
September averages 34 mm of rainfall in Geraldton, about average for rainfall. The wettest on record was 79 mm in 2014.
The hottest September reached 27.8°C in 2015. The coldest dipped to 11.8°C in 2004.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 0.4°C. Daytime highs moved from 19.6°C to 20.2°C and overnight lows from 16.6°C to 16.8°C over the same span.
September is one of the cooler months of the year in Geraldton and about average for rainfall, so plan for around 19.5°C daytime highs and 16.5°C at night.
Not quite — September is the 3rd coolest month in Geraldton, averaging 18°C.
For September in Geraldton, pack light layers you can adjust through the day, with typical highs of 19.5°C and lows of 16.5°C.
Relative humidity in September averages 71% — moderately humid.
Average wind speed in September is 5.7 m/s. The windiest September on record averaged 6.4 m/s (2024).
The wettest September on record was 2014 with 79 mm. On average, September sees 34 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 Geraldton 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.
