September is one of the cooler months of the year in Waitakere, with average highs near 14.7°C and lows around 12.2°C (mean 13.5°C). It is about average for rainfall, averaging 104 mm of rainfall and 81% relative humidity across the period.
September is one of the cooler months of the year in Waitakere. Across 45 years of records, the warmest September in Waitakere was 2005 — when the month averaged 14.5°C — while the coldest was 1992 at 11.7°C. Typical September days reach 14.7°C with nights near 12.2°C. The long-term September temperature trend is broadly flat.
September is about average for rainfall in Waitakere, averaging 104 mm of rainfall. The wettest September on record was 1997 with 166 mm, while the driest was 2006 at 52 mm.
Relative humidity in Waitakere during September averages 81%. The most humid September was 2016 at 85%, and the least humid were 1990 and 1993 at 76%.
September receives about 4 kWh/m²/day of solar energy in Waitakere. The sunniest Septembers were 2008 and 2020 at 4.3 kWh/m²/day, and the cloudiest were 1997 and 2016 at 3.6.
Average wind speed in Waitakere during September is 6.1 m/s. The windiest September was 1994 at 7.6 m/s, while the calmest was 2006 at 4.4 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 13.4°C | 13.0°C | 13.7°C | 13.4°C | 13.8°C | +0.4°C |
| Avg High | 14.7°C | 14.2°C | 15.0°C | 14.6°C | 15.0°C | +0.3°C |
| Avg Low | 12.2°C | 11.7°C | 12.3°C | 12.2°C | 12.5°C | +0.3°C |
| Avg Rain | 99 mm | 100 mm | 80 mm | 123 mm | 124 mm | +25 mm |
September temperatures in Waitakere have risen by about 0.6°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 7.6°C (1989) to a record high of 18.5°C (2003).
Rainfall in September is about average for rainfall, averaging 104 mm, with a wettest year of 166 mm.
A quieter season to visit Waitakere
If your dates are flexible, the more temperate months of February and January tend to be the most comfortable for visiting Waitakere. That said, September — with days averaging 14.7°C and nights around 12.2°C (mean 13.5°C) and higher rainfall (104 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 | 15.2°C | 14.0°C | 12.9°C | 16.9°C | 10.5°C | 131 mm | 81% | 6.8 m/s | 4 |
| 2024 | 15.0°C | 13.8°C | 12.6°C | 17.0°C | 11.0°C | 101 mm | 81% | 6.3 m/s | 4.1 |
| 2023 | 15.3°C | 14.1°C | 12.8°C | 17.9°C | 10.2°C | 132 mm | 85% | 6.2 m/s | 4.1 |
| 2022 | 15.2°C | 14.0°C | 12.8°C | 17.4°C | 9.8°C | 134 mm | 78% | 4.9 m/s | 4.2 |
| 2021 | 14.7°C | 13.4°C | 12.1°C | 17.2°C | 10.2°C | 163 mm | 80% | 6.4 m/s | 4 |
| 2020 | 14.6°C | 13.4°C | 12.1°C | 18.0°C | 8.7°C | 83 mm | 79% | 6.4 m/s | 4.3 |
| 2019 | 14.7°C | 13.5°C | 12.3°C | 16.8°C | 10.5°C | 126 mm | 81% | 6.2 m/s | 4.2 |
| 2018 | 14.5°C | 13.4°C | 12.3°C | 17.1°C | 10.5°C | 59 mm | 81% | 5.8 m/s | 4.1 |
| 2017 | 14.8°C | 13.7°C | 12.7°C | 17.4°C | 11.1°C | 121 mm | 82% | 6.5 m/s | 4.1 |
| 2016 | 15.1°C | 13.9°C | 12.7°C | 17.0°C | 9.1°C | 163 mm | 85% | 5.6 m/s | 3.6 |
| 2015 | 13.9°C | 12.8°C | 11.7°C | 16.1°C | 10.1°C | 136 mm | 80% | 5.7 m/s | 4.1 |
| 2014 | 14.8°C | 13.5°C | 12.3°C | 16.5°C | 9.8°C | 165 mm | 83% | 6.3 m/s | 3.8 |
| 2013 | 14.7°C | 13.5°C | 12.3°C | 16.7°C | 8.5°C | 138 mm | 82% | 6.6 m/s | 3.8 |
| 2012 | 14.8°C | 13.5°C | 12.2°C | 16.8°C | 9.2°C | 109 mm | 78% | 6.9 m/s | 4 |
| 2011 | 14.1°C | 12.9°C | 11.6°C | 15.6°C | 10.2°C | 80 mm | 76% | 5.7 m/s | 4.2 |
| 2010 | 15.0°C | 13.7°C | 12.3°C | 17.4°C | 10.8°C | 136 mm | 83% | 7.2 m/s | 3.7 |
| 2009 | 15.2°C | 13.8°C | 12.4°C | 17.9°C | 8.2°C | 114 mm | 82% | 5.3 m/s | 4 |
| 2008 | 14.8°C | 13.5°C | 12.3°C | 16.4°C | 10.9°C | 57 mm | 82% | 5.6 m/s | 4.3 |
| 2007 | 14.9°C | 13.5°C | 12.2°C | 17.0°C | 9.0°C | 59 mm | 81% | 5 m/s | 3.9 |
| 2006 | 14.9°C | 13.8°C | 12.6°C | 17.6°C | 10.3°C | 52 mm | 83% | 4.4 m/s | 4.1 |
| 2005 🔥 | 15.9°C | 14.5°C | 13.1°C | 17.7°C | 10.3°C | 79 mm | 81% | 5.8 m/s | 3.9 |
| 2004 | 14.0°C | 12.7°C | 11.3°C | 16.1°C | 9.3°C | 82 mm | 79% | 6.6 m/s | 3.9 |
| 2003 | 15.0°C | 13.7°C | 12.5°C | 18.5°C | 10.8°C | 150 mm | 83% | 7.1 m/s | 3.8 |
| 2002 | 14.8°C | 13.5°C | 12.2°C | 16.7°C | 9.7°C | 85 mm | 80% | 6.4 m/s | 4.1 |
| 2001 | 15.4°C | 14.0°C | 12.7°C | 17.2°C | 11.0°C | 63 mm | 80% | 5 m/s | 4.1 |
| 2000 | 14.8°C | 13.5°C | 12.2°C | 16.7°C | 8.3°C | 61 mm | 79% | 5.9 m/s | 3.9 |
| 1999 | 15.1°C | 13.8°C | 12.4°C | 16.8°C | 10.0°C | 54 mm | 80% | 5.3 m/s | 4.1 |
| 1998 | 15.4°C | 14.1°C | 12.8°C | 18.2°C | 11.2°C | 60 mm | 79% | 5.9 m/s | 3.7 |
| 1997 🌧️ | 14.0°C | 12.8°C | 11.7°C | 15.9°C | 8.7°C | 166 mm | 83% | 6.5 m/s | 3.6 |
| 1996 | 15.3°C | 13.9°C | 12.5°C | 17.0°C | 10.2°C | 100 mm | 84% | 5.6 m/s | 3.9 |
| 1995 | 14.5°C | 13.3°C | 12.0°C | 18.1°C | 9.1°C | 96 mm | 82% | 5.3 m/s | 4.2 |
| 1994 | 13.6°C | 12.4°C | 11.2°C | 15.9°C | 9.2°C | 151 mm | 81% | 7.6 m/s | 3.8 |
| 1993 | 13.3°C | 12.0°C | 10.7°C | 15.6°C | 8.0°C | 59 mm | 76% | 6.5 m/s | 3.8 |
| 1992 ❄️ | 12.8°C | 11.7°C | 10.5°C | 14.2°C | 8.2°C | 115 mm | 82% | 6 m/s | 3.8 |
| 1991 | 14.3°C | 13.2°C | 12.2°C | 16.6°C | 10.3°C | 121 mm | 83% | 6 m/s | 4 |
| 1990 | 13.7°C | 12.5°C | 11.4°C | 15.5°C | 9.2°C | 78 mm | 76% | 4.9 m/s | 4.1 |
| 1989 | 15.7°C | 14.2°C | 12.7°C | 17.7°C | 7.6°C | 91 mm | 82% | 5.5 m/s | 3.8 |
| 1988 | 15.0°C | 13.8°C | 12.6°C | 17.0°C | 10.3°C | 119 mm | 85% | 6.1 m/s | 3.7 |
| 1987 | 14.3°C | 13.4°C | 12.4°C | 16.1°C | 11.3°C | 134 mm | 80% | 7.2 m/s | 3.7 |
| 1986 | 14.2°C | 12.9°C | 11.7°C | 16.1°C | 9.2°C | 84 mm | 82% | 6.4 m/s | 4 |
| 1985 | 14.8°C | 13.5°C | 12.2°C | 16.6°C | 11.1°C | 85 mm | 80% | 7.4 m/s | 4.2 |
| 1984 | 14.7°C | 13.2°C | 11.8°C | 16.2°C | 9.6°C | 99 mm | 80% | 5.4 m/s | 4 |
| 1983 | 14.7°C | 13.5°C | 12.3°C | 16.9°C | 10.5°C | 97 mm | 83% | 6.3 m/s | — |
| 1982 | 14.5°C | 13.2°C | 12.0°C | 16.9°C | 9.6°C | 64 mm | 79% | 4.9 m/s | — |
| 1981 | 14.2°C | 13.1°C | 12.0°C | 16.5°C | 10.3°C | 118 mm | 80% | 7.5 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 14.7°C with lows near 12.2°C (mean 13.5°C), based on 45 years of NASA POWER data.
September averages 104 mm of rainfall in Waitakere, about average for rainfall. The wettest on record was 166 mm in 1997.
The hottest September reached 18.5°C in 2003. The coldest dipped to 7.6°C in 1989.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 0.6°C. Daytime highs moved from 14.6°C to 15.1°C and overnight lows from 12.1°C to 12.6°C over the same span.
September is one of the cooler months of the year in Waitakere and about average for rainfall, so plan for around 14.7°C daytime highs and 12.2°C at night.
Not quite — September is the 3rd coolest month in Waitakere, averaging 13.5°C.
For September in Waitakere, pack light layers you can adjust through the day, with typical highs of 14.7°C and lows of 12.2°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 81% — quite humid.
Average wind speed in September is 6.1 m/s. The windiest September on record averaged 7.6 m/s (1994).
The wettest September on record was 1997 with 166 mm. On average, September sees 104 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 Waitakere 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.
