September is one of the cooler months of the year in Invercargill, with average highs near 11.6°C and lows around 6.9°C (mean 9.3°C). It is about average for rainfall, averaging 98 mm of rainfall and 81% relative humidity across the period.
September is one of the cooler months of the year in Invercargill. Across 45 years of records, the warmest September in Invercargill was 1989 — when the month averaged 11°C — while the coldest was 1992 at 7.4°C. Typical September days reach 11.6°C with nights near 6.9°C. The long-term September temperature trend is broadly flat.
September is about average for rainfall in Invercargill, averaging 98 mm of rainfall. The wettest September on record was 2010 with 181 mm, while the driest was 1989 at 18 mm.
Relative humidity in Invercargill during September averages 81%. The most humid September was 1991 at 84%, and the least humid was 2025 at 78%.
September receives about 3.2 kWh/m²/day of solar energy in Invercargill. The sunniest September was 1985 at 3.8 kWh/m²/day, and the cloudiest were 1995, 2010 and 2020 at 2.9.
Average wind speed in Invercargill during September is 4.5 m/s. The windiest Septembers were 1981 and 2025 at 6.1 m/s, while the calmest was 1989 at 2.9 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 9.5°C | 8.7°C | 9.6°C | 9.2°C | 9.5°C | 0°C |
| Avg High | 11.9°C | 11.1°C | 11.9°C | 11.5°C | 11.7°C | -0.2°C |
| Avg Low | 7.1°C | 6.4°C | 7.2°C | 6.9°C | 7.3°C | +0.2°C |
| Avg Rain | 95 mm | 78 mm | 100 mm | 99 mm | 132 mm | +37 mm |
September temperatures in Invercargill have stayed relatively stable across the record.
September has ranged from a record low of 1.1°C (1997) to a record high of 18.2°C (2022).
Rainfall in September is about average for rainfall, averaging 98 mm, with a wettest year of 181 mm.
A quieter season to visit Invercargill
If your dates are flexible, the more temperate months of February and January tend to be the most comfortable for visiting Invercargill. That said, September — with days averaging 11.6°C and nights around 6.9°C (mean 9.3°C) and higher rainfall (98 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 | 11.5°C | 9.4°C | 7.3°C | 14.7°C | 4.8°C | 165 mm | 78% | 6.1 m/s | 3.1 |
| 2024 | 11.4°C | 9.4°C | 7.3°C | 15.6°C | 4.3°C | 144 mm | 80% | 5.5 m/s | 3 |
| 2023 | 12.5°C | 10.1°C | 7.7°C | 17.9°C | 4.3°C | 126 mm | 80% | 5 m/s | 3.2 |
| 2022 | 12.1°C | 9.8°C | 7.4°C | 18.2°C | 3.5°C | 70 mm | 80% | 3.3 m/s | 3.3 |
| 2021 | 11.4°C | 9.1°C | 6.8°C | 14.5°C | 2.7°C | 151 mm | 80% | 5 m/s | 3.1 |
| 2020 | 11.3°C | 9.4°C | 7.4°C | 15.4°C | 3.5°C | 138 mm | 81% | 5.1 m/s | 2.9 |
| 2019 | 11.2°C | 9.0°C | 6.9°C | 14.6°C | 2.7°C | 79 mm | 80% | 5 m/s | 3.4 |
| 2018 | 11.9°C | 9.5°C | 7.0°C | 16.5°C | 4.2°C | 62 mm | 81% | 3.9 m/s | 3.4 |
| 2017 | 11.9°C | 9.5°C | 7.2°C | 17.8°C | 4.0°C | 114 mm | 83% | 4 m/s | 3.2 |
| 2016 | 12.8°C | 10.1°C | 7.4°C | 16.3°C | 3.5°C | 48 mm | 82% | 3.4 m/s | 3.3 |
| 2015 | 10.5°C | 8.1°C | 5.7°C | 14.7°C | 2.3°C | 72 mm | 81% | 4.3 m/s | 3.3 |
| 2014 | 11.7°C | 9.3°C | 7.0°C | 16.0°C | 4.8°C | 68 mm | 81% | 3.8 m/s | 3.3 |
| 2013 | 11.6°C | 9.3°C | 7.0°C | 15.7°C | 3.4°C | 114 mm | 80% | 4.3 m/s | 3.1 |
| 2012 | 12.0°C | 9.7°C | 7.4°C | 16.5°C | 3.7°C | 125 mm | 80% | 4.4 m/s | 3.1 |
| 2011 | 10.7°C | 8.7°C | 6.7°C | 16.9°C | 4.1°C | 125 mm | 82% | 4.7 m/s | 3.2 |
| 2010 🌧️ | 10.6°C | 8.6°C | 6.7°C | 14.9°C | 3.6°C | 181 mm | 81% | 5.6 m/s | 2.9 |
| 2009 | 11.9°C | 9.5°C | 7.0°C | 15.7°C | 3.9°C | 83 mm | 80% | 4.4 m/s | 3 |
| 2008 | 12.0°C | 9.8°C | 7.6°C | 18.0°C | 4.9°C | 126 mm | 81% | 4.5 m/s | 3 |
| 2007 | 11.9°C | 9.5°C | 7.1°C | 16.0°C | 4.1°C | 85 mm | 81% | 3.9 m/s | 3.2 |
| 2006 | 12.1°C | 10.0°C | 7.8°C | 16.4°C | 5.2°C | 128 mm | 80% | 5.2 m/s | 3.3 |
| 2005 | 12.5°C | 9.9°C | 7.4°C | 17.6°C | 3.6°C | 74 mm | 81% | 4 m/s | 3.2 |
| 2004 | 10.4°C | 8.6°C | 6.8°C | 14.0°C | 3.9°C | 106 mm | 81% | 5.2 m/s | 3 |
| 2003 | 10.9°C | 8.5°C | 6.1°C | 14.2°C | 3.2°C | 116 mm | 80% | 4.7 m/s | 3.1 |
| 2002 | 11.7°C | 9.5°C | 7.3°C | 15.1°C | 4.4°C | 131 mm | 80% | 5.6 m/s | 3 |
| 2001 | 13.6°C | 10.9°C | 8.1°C | 17.3°C | 5.0°C | 75 mm | 80% | 4.3 m/s | 3.2 |
| 2000 | 12.1°C | 9.6°C | 7.1°C | 14.9°C | 3.8°C | 71 mm | 80% | 4.9 m/s | 3.2 |
| 1999 | 12.2°C | 9.8°C | 7.4°C | 14.9°C | 3.7°C | 90 mm | 82% | 4.5 m/s | 3.1 |
| 1998 | 11.5°C | 9.4°C | 7.3°C | 15.7°C | 3.2°C | 115 mm | 80% | 5.5 m/s | 3.1 |
| 1997 | 10.2°C | 7.8°C | 5.3°C | 15.0°C | 1.1°C | 43 mm | 79% | 3.6 m/s | 3.3 |
| 1996 | 13.2°C | 10.4°C | 7.5°C | 17.2°C | 4.3°C | 63 mm | 80% | 3.5 m/s | 3.2 |
| 1995 | 10.5°C | 8.3°C | 6.1°C | 15.9°C | 3.3°C | 134 mm | 82% | 4.6 m/s | 2.9 |
| 1994 | 9.8°C | 7.7°C | 5.7°C | 15.4°C | 2.9°C | 123 mm | 81% | 4.5 m/s | 3.2 |
| 1993 | 10.5°C | 8.4°C | 6.4°C | 15.0°C | 2.7°C | 65 mm | 81% | 4.7 m/s | 3.2 |
| 1992 ❄️ | 10.3°C | 7.4°C | 4.6°C | 14.5°C | 1.8°C | 43 mm | 81% | 3.4 m/s | 3.5 |
| 1991 | 11.7°C | 9.4°C | 7.0°C | 15.2°C | 5.0°C | 56 mm | 84% | 3.9 m/s | 3.2 |
| 1990 | 11.2°C | 8.8°C | 6.5°C | 14.3°C | 4.2°C | 43 mm | 80% | 4.4 m/s | 3.4 |
| 1989 🔥 | 14.2°C | 11.0°C | 7.8°C | 17.6°C | 4.4°C | 18 mm | 80% | 2.9 m/s | 3.6 |
| 1988 | 12.0°C | 9.9°C | 7.7°C | 16.5°C | 4.1°C | 108 mm | 83% | 4.5 m/s | 3 |
| 1987 | 11.0°C | 8.7°C | 6.5°C | 13.7°C | 3.9°C | 110 mm | 81% | 5.3 m/s | 3.1 |
| 1986 | 11.4°C | 9.1°C | 6.8°C | 15.9°C | 2.3°C | 87 mm | 81% | 4.5 m/s | 3.6 |
| 1985 | 13.1°C | 10.3°C | 7.5°C | 17.3°C | 3.6°C | 72 mm | 79% | 4.2 m/s | 3.8 |
| 1984 | 12.5°C | 9.6°C | 6.6°C | 16.2°C | 3.7°C | 104 mm | 82% | 3.1 m/s | 3.6 |
| 1983 | 10.9°C | 8.7°C | 6.6°C | 15.2°C | 4.4°C | 108 mm | 82% | 5 m/s | — |
| 1982 | 11.5°C | 9.2°C | 7.0°C | 14.7°C | 4.3°C | 92 mm | 80% | 3.7 m/s | — |
| 1981 | 10.8°C | 9.0°C | 7.1°C | 13.5°C | 4.8°C | 159 mm | 80% | 6.1 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 11.6°C with lows near 6.9°C (mean 9.3°C), based on 45 years of NASA POWER data.
September averages 98 mm of rainfall in Invercargill, about average for rainfall. The wettest on record was 181 mm in 2010.
The hottest September reached 18.2°C in 2022. The coldest dipped to 1.1°C in 1997.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 0.2°C. Daytime highs moved from 11.8°C to 11.8°C and overnight lows from 7°C to 7.3°C over the same span.
September is one of the cooler months of the year in Invercargill and about average for rainfall, so plan for around 11.6°C daytime highs and 6.9°C at night.
Not quite — September is the 4th coolest month in Invercargill, averaging 9.3°C.
For September in Invercargill, pack warm layers and a jacket for chilly mornings, with typical highs of 11.6°C and lows of 6.9°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 81% — quite humid.
Average wind speed in September is 4.5 m/s. The windiest September on record averaged 6.1 m/s (1981).
The wettest September on record was 2010 with 181 mm. On average, September sees 98 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 Invercargill 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.
