September is one of the cooler months of the year in Timaru, with average highs near 11.9°C and lows around 6.5°C (mean 9.2°C). It is one of the drier months, averaging 47 mm of rainfall and 79% relative humidity across the period.
September is one of the cooler months of the year in Timaru. Across 45 years of records, the warmest September in Timaru was 1988 — when the month averaged 10.3°C — while the coldest was 1992 at 6.6°C. Typical September days reach 11.9°C with nights near 6.5°C. The long-term trend is warming, about 0.2°C per decade.
September is one of the drier months in Timaru, averaging 47 mm of rainfall. The wettest September on record was 1995 with 140 mm, while the driest were 2001 and 2006 at 17 mm.
Relative humidity in Timaru during September averages 79%. The most humid September was 1992 at 85%, and the least humid was 2020 at 71%.
September receives about 3.6 kWh/m²/day of solar energy in Timaru. The sunniest Septembers were 2020, 2021 and 2025, among others at 4 kWh/m²/day, and the cloudiest were 1995, 2005 and 2016, among others at 3.1.
Average wind speed in Timaru during September is 3.7 m/s. The windiest September was 2010 at 4.6 m/s, while the calmest was 1982 at 2.8 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 9.2°C | 8.6°C | 9.6°C | 9.2°C | 9.8°C | +0.6°C |
| Avg High | 11.8°C | 11.2°C | 12.4°C | 11.9°C | 12.8°C | +1°C |
| Avg Low | 6.5°C | 5.9°C | 6.7°C | 6.5°C | 6.8°C | +0.3°C |
| Avg Rain | 61 mm | 56 mm | 43 mm | 34 mm | 36 mm | -25 mm |
September temperatures in Timaru have risen by about 0.7°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 2°C (1997) to a record high of 19.1°C (1999).
Rainfall in September is one of the drier months, averaging 47 mm, with a wettest year of 140 mm.
A quieter season to visit Timaru
If your dates are flexible, the more temperate months of February and January tend to be the most comfortable for visiting Timaru. That said, September — with days averaging 11.9°C and nights around 6.5°C (mean 9.2°C) and moderate rainfall (47 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 | 13.0°C | 9.8°C | 6.5°C | 17.0°C | 3.7°C | 24 mm | 73% | 4.2 m/s | 4 |
| 2024 | 12.8°C | 9.7°C | 6.6°C | 16.1°C | 3.8°C | 53 mm | 76% | 3.7 m/s | 3.8 |
| 2023 | 13.1°C | 10.2°C | 7.4°C | 17.6°C | 4.2°C | 48 mm | 78% | 4.2 m/s | 3.6 |
| 2022 | 11.6°C | 9.2°C | 6.7°C | 16.9°C | 3.0°C | 34 mm | 82% | 3.2 m/s | 3.5 |
| 2021 | 12.4°C | 9.5°C | 6.5°C | 16.7°C | 3.6°C | 22 mm | 74% | 3.9 m/s | 4 |
| 2020 | 13.7°C | 10.2°C | 6.8°C | 18.4°C | 4.0°C | 35 mm | 71% | 4 m/s | 4 |
| 2019 | 12.1°C | 9.2°C | 6.2°C | 17.6°C | 3.0°C | 31 mm | 78% | 3.5 m/s | 3.5 |
| 2018 | 12.2°C | 9.4°C | 6.6°C | 18.6°C | 3.9°C | 28 mm | 79% | 3.3 m/s | 3.8 |
| 2017 | 12.2°C | 9.8°C | 7.5°C | 18.3°C | 5.0°C | 39 mm | 82% | 4.1 m/s | 3.3 |
| 2016 | 11.9°C | 9.6°C | 7.3°C | 17.9°C | 4.5°C | 25 mm | 84% | 3.5 m/s | 3.1 |
| 2015 | 10.6°C | 8.1°C | 5.5°C | 16.6°C | 3.1°C | 37 mm | 80% | 3.8 m/s | 3.6 |
| 2014 | 12.2°C | 9.4°C | 6.6°C | 17.7°C | 5.0°C | 33 mm | 79% | 3.2 m/s | 3.8 |
| 2013 | 11.9°C | 9.4°C | 6.8°C | 15.0°C | 3.3°C | 37 mm | 78% | 3.6 m/s | 3.6 |
| 2012 | 12.2°C | 9.5°C | 6.8°C | 16.5°C | 3.7°C | 39 mm | 78% | 3.9 m/s | 3.6 |
| 2011 | 11.7°C | 8.8°C | 5.8°C | 14.7°C | 2.8°C | 33 mm | 76% | 3.5 m/s | 3.7 |
| 2010 | 11.5°C | 8.8°C | 6.0°C | 15.5°C | 2.9°C | 39 mm | 78% | 4.6 m/s | 3.5 |
| 2009 | 12.2°C | 9.3°C | 6.4°C | 17.2°C | 3.8°C | 34 mm | 76% | 3.6 m/s | 3.7 |
| 2008 | 12.6°C | 9.8°C | 6.9°C | 17.8°C | 4.0°C | 39 mm | 79% | 3.3 m/s | 3.4 |
| 2007 | 12.1°C | 9.4°C | 6.6°C | 16.0°C | 3.5°C | 41 mm | 78% | 3.1 m/s | 3.5 |
| 2006 | 13.3°C | 10.1°C | 7.0°C | 16.7°C | 4.0°C | 17 mm | 78% | 3.7 m/s | 3.7 |
| 2005 | 12.3°C | 9.7°C | 7.2°C | 17.2°C | 3.8°C | 45 mm | 80% | 3.3 m/s | 3.1 |
| 2004 | 11.7°C | 8.7°C | 5.6°C | 18.1°C | 3.1°C | 46 mm | 75% | 4 m/s | 3.6 |
| 2003 | 11.5°C | 8.9°C | 6.3°C | 14.8°C | 4.1°C | 87 mm | 78% | 4.2 m/s | 3.6 |
| 2002 | 13.5°C | 10.1°C | 6.8°C | 17.6°C | 3.3°C | 40 mm | 73% | 4.2 m/s | 3.5 |
| 2001 | 13.0°C | 10.1°C | 7.3°C | 17.7°C | 4.7°C | 17 mm | 78% | 3.3 m/s | 3.6 |
| 2000 | 11.7°C | 9.4°C | 7.0°C | 17.3°C | 4.1°C | 64 mm | 80% | 4.2 m/s | 3.3 |
| 1999 | 12.8°C | 9.7°C | 6.7°C | 19.1°C | 4.0°C | 28 mm | 78% | 3.3 m/s | 3.3 |
| 1998 | 12.8°C | 9.6°C | 6.4°C | 16.9°C | 3.8°C | 25 mm | 75% | 3.9 m/s | 3.6 |
| 1997 | 10.3°C | 7.8°C | 5.3°C | 16.8°C | 2.0°C | 25 mm | 79% | 3.4 m/s | 3.5 |
| 1996 | 13.0°C | 10.1°C | 7.3°C | 18.3°C | 4.7°C | 27 mm | 80% | 2.9 m/s | 3.5 |
| 1995 🌧️ | 10.8°C | 8.1°C | 5.4°C | 15.6°C | 2.1°C | 140 mm | 81% | 3.8 m/s | 3.1 |
| 1994 | 10.4°C | 7.8°C | 5.2°C | 13.9°C | 2.3°C | 43 mm | 78% | 4.1 m/s | 3.4 |
| 1993 | 10.7°C | 8.0°C | 5.3°C | 15.5°C | 2.9°C | 77 mm | 79% | 4.2 m/s | 3.4 |
| 1992 ❄️ | 8.6°C | 6.6°C | 4.6°C | 12.8°C | 3.1°C | 78 mm | 85% | 3.6 m/s | 3.1 |
| 1991 | 11.3°C | 9.1°C | 6.9°C | 14.5°C | 4.9°C | 78 mm | 84% | 3 m/s | 3.4 |
| 1990 | 11.5°C | 8.8°C | 6.0°C | 16.5°C | 3.4°C | 39 mm | 79% | 3.4 m/s | 3.5 |
| 1989 | 12.1°C | 9.9°C | 7.6°C | 16.8°C | 3.3°C | 34 mm | 84% | 3.2 m/s | 3.6 |
| 1988 🔥 | 13.1°C | 10.3°C | 7.5°C | 17.7°C | 4.4°C | 42 mm | 80% | 3 m/s | 3.6 |
| 1987 | 11.7°C | 9.0°C | 6.3°C | 15.0°C | 3.9°C | 77 mm | 79% | 4.1 m/s | 3.4 |
| 1986 | 11.1°C | 8.5°C | 5.9°C | 16.8°C | 3.5°C | 55 mm | 80% | 3.1 m/s | 4 |
| 1985 | 12.2°C | 9.6°C | 6.9°C | 16.3°C | 3.8°C | 46 mm | 80% | 3.8 m/s | 4 |
| 1984 | 11.2°C | 8.8°C | 6.3°C | 15.6°C | 4.1°C | 68 mm | 84% | 3.2 m/s | 3.8 |
| 1983 | 11.4°C | 8.7°C | 6.1°C | 16.8°C | 4.3°C | 123 mm | 81% | 4.1 m/s | — |
| 1982 | 11.7°C | 9.1°C | 6.4°C | 16.4°C | 3.3°C | 58 mm | 80% | 2.8 m/s | — |
| 1981 | 11.8°C | 8.9°C | 5.9°C | 15.3°C | 3.2°C | 43 mm | 76% | 4.3 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 11.9°C with lows near 6.5°C (mean 9.2°C), based on 45 years of NASA POWER data.
September averages 47 mm of rainfall in Timaru, one of the drier months. The wettest on record was 140 mm in 1995.
The hottest September reached 19.1°C in 1999. The coldest dipped to 2°C in 1997.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 0.7°C. Daytime highs moved from 11.7°C to 12.6°C and overnight lows from 6.3°C to 6.7°C over the same span.
September is one of the cooler months of the year in Timaru and one of the drier months, so plan for around 11.9°C daytime highs and 6.5°C at night.
Not quite — September is the 4th coolest month in Timaru, averaging 9.2°C.
For September in Timaru, pack warm layers and a jacket for chilly mornings, with typical highs of 11.9°C and lows of 6.5°C.
Relative humidity in September averages 79% — quite humid.
Average wind speed in September is 3.7 m/s. The windiest September on record averaged 4.6 m/s (2010).
The wettest September on record was 1995 with 140 mm. On average, September sees 47 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 Timaru 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.
