September is close to Theni's year-round average, with average highs near 31.2°C and lows around 17.9°C (mean 24.5°C). It is a relatively wet time of year, averaging 133 mm of rainfall and 80% relative humidity across the period.
September is close to Theni's year-round average. Across 45 years of records, the warmest September in Theni was 2015 — when the month averaged 26.5°C — while the coldest was 1983 at 22.9°C. Typical September days reach 31.2°C with nights near 17.9°C. The long-term trend is warming, about 0.3°C per decade.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 24.0°C | 24.2°C | 24.5°C | 25.3°C | 24.5°C | +0.5°C |
| Avg High | 30.7°C | 30.7°C | 31.1°C | 32.5°C | 30.9°C | +0.2°C |
| Avg Low | 17.3°C | 17.8°C | 17.9°C | 18.1°C | 18.2°C | +0.9°C |
| Avg Rain | 166 mm | 118 mm | 139 mm | 115 mm | 125 mm | -41 mm |
September temperatures in Theni have risen by about 0.9°C between 1981–1985 and 2021–2025.
September has ranged from a record low of 16.3°C (1982) to a record high of 34.4°C (2015).
Rainfall in September is a relatively wet time of year, averaging 133 mm, with a wettest year of 324 mm.
A good time to visit Theni
September is a good time to visit Theni, with days averaging 31.2°C and nights around 17.9°C (mean 24.5°C, close to Theni's yearly average) and higher rainfall. January and February are marginally more temperate, but September still suits most travellers.
| Year | High | Low | Avg | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|
| 2025 | 32.6°C | 19.1°C | 25.9°C | 127 mm | 78% | 1.8 m/s | 4.9 |
| 2024 | 32.1°C | 18.3°C | 25.2°C | 34 mm | 79% | 2.1 m/s | 5.5 |
| 2023 | 31.1°C | 18.0°C | 24.5°C | 161 mm | 79% | 1.9 m/s | 4.6 |
| 2022 | 29.7°C | 17.9°C | 23.8°C | 93 mm | 83% | 1.4 m/s | 5.6 |
| 2021 | 29.9°C | 17.7°C | 23.8°C | 191 mm | 82% | 1.8 m/s | 4.7 |
| 2020 | 30.1°C | 18.0°C | 24.0°C | 144 mm | 82% | 1.9 m/s | 4.3 |
| 2019 | 30.7°C | 18.5°C | 24.6°C | 215 mm | 81% | 1.7 m/s | 4.9 |
| 2018 | 33.8°C | 17.8°C | 25.8°C | 119 mm | 74% | 1.4 m/s | 5.8 |
| 2017 | 29.6°C | 18.4°C | 24.0°C | 201 mm | 85% | 1.4 m/s | 4.9 |
| 2016 | 33.1°C | 17.7°C | 25.4°C | 28 mm | 73% | 2.2 m/s | 5.6 |
| 2015 🔥 | 34.4°C | 18.7°C | 26.5°C | 147 mm | 76% | 1.6 m/s | 5.3 |
| 2014 | 31.7°C | 18.3°C | 25.0°C | 96 mm | 79% | 1.8 m/s | 5.3 |
| 2013 | 33.4°C | 17.4°C | 25.4°C | 67 mm | 78% | 1.9 m/s | 5 |
| 2012 | 34.0°C | 18.8°C | 26.4°C | 58 mm | 71% | 2 m/s | 5.5 |
| 2011 | 33.0°C | 17.7°C | 25.4°C | 99 mm | 74% | 2.1 m/s | 5.4 |
| 2010 | 31.4°C | 17.9°C | 24.6°C | 122 mm | 77% | 1.6 m/s | 5 |
| 2009 | 33.7°C | 18.4°C | 26.0°C | 88 mm | 77% | 2 m/s | 5 |
| 2008 | 31.8°C | 17.0°C | 24.4°C | 87 mm | 80% | 1.7 m/s | 5.7 |
| 2007 | 29.2°C | 18.2°C | 23.7°C | 140 mm | 84% | 1.9 m/s | 4.6 |
| 2006 | 28.8°C | 17.2°C | 23.0°C | 232 mm | 85% | 1.8 m/s | 5 |
| 2005 | 30.7°C | 18.1°C | 24.4°C | 154 mm | 83% | 2.1 m/s | 5.2 |
| 2004 | 29.6°C | 18.1°C | 23.8°C | 252 mm | 84% | 1.2 m/s | 4.9 |
| 2003 | 31.8°C | 18.1°C | 25.0°C | 53 mm | 77% | 1.7 m/s | 6 |
| 2002 | 33.5°C | 17.2°C | 25.4°C | 52 mm | 74% | 1.7 m/s | 6.1 |
| 2001 | 31.6°C | 18.3°C | 25.0°C | 215 mm | 82% | 1.5 m/s | 5.5 |
| 2000 | 30.6°C | 18.6°C | 24.6°C | 117 mm | 83% | 1.4 m/s | 5.3 |
| 1999 | 33.0°C | 18.2°C | 25.6°C | 32 mm | 74% | 1.7 m/s | 5.7 |
| 1998 | 28.9°C | 18.4°C | 23.6°C | 257 mm | 86% | 1.8 m/s | 5.2 |
| 1997 | 30.0°C | 17.6°C | 23.8°C | 188 mm | 84% | 1.4 m/s | 5.2 |
| 1996 | 28.6°C | 18.3°C | 23.5°C | 139 mm | 84% | 1.9 m/s | 4.2 |
| 1995 | 31.9°C | 17.6°C | 24.8°C | 78 mm | 79% | 2.1 m/s | 4.9 |
| 1994 | 31.2°C | 16.3°C | 23.8°C | 104 mm | 82% | 1.7 m/s | 5.1 |
| 1993 | 31.5°C | 18.0°C | 24.7°C | 37 mm | 77% | 1.5 m/s | 5.1 |
| 1992 | 29.6°C | 18.0°C | 23.8°C | 183 mm | 84% | 1.5 m/s | 4.9 |
| 1991 | 30.3°C | 17.5°C | 23.9°C | 85 mm | 82% | 1.4 m/s | 5.7 |
| 1990 | 31.6°C | 18.0°C | 24.8°C | 73 mm | 74% | 1.6 m/s | 5.2 |
| 1989 | 30.5°C | 17.2°C | 23.9°C | 162 mm | 82% | 1.6 m/s | 4.9 |
| 1988 | 29.2°C | 17.9°C | 23.5°C | 312 mm | 87% | 1.8 m/s | 4.4 |
| 1987 | 32.1°C | 17.8°C | 24.9°C | 93 mm | 80% | 1.4 m/s | 5.3 |
| 1986 | 32.2°C | 18.1°C | 25.1°C | 123 mm | 77% | 1.7 m/s | 5.1 |
| 1985 | 32.1°C | 17.0°C | 24.5°C | 113 mm | 79% | 1.6 m/s | 5.1 |
| 1984 | 32.6°C | 17.2°C | 24.9°C | 92 mm | 76% | 1.5 m/s | 5.3 |
| 1983 ❄️ | 29.1°C | 16.8°C | 22.9°C | 241 mm | 83% | 1.8 m/s | — |
| 1982 | 30.1°C | 16.3°C | 23.2°C | 38 mm | 80% | 1.7 m/s | — |
| 1981 🌧️ | 28.6°C | 17.8°C | 23.2°C | 324 mm | 87% | 1.4 m/s | — |
Actual recorded September data for each year, 1981–2025 — sourced from NASA POWER.
The average high in September is around 31.2°C with lows near 17.9°C (mean 24.5°C), based on 45 years of NASA POWER data.
September averages 133 mm of rainfall in Theni, a relatively wet time of year. The wettest on record was 324 mm in 1981.
The hottest September reached 34.4°C in 2015. The coldest dipped to 16.3°C in 1982.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average September temperatures have risen by about 0.9°C. Daytime highs moved from 30.5°C to 31.1°C and overnight lows from 17°C to 18.2°C over the same span.
September is close to Theni's year-round average and a relatively wet time of year, so plan for around 31.2°C daytime highs and 17.9°C at night.
Not quite — September is the 6th coolest month in Theni, averaging 24.5°C.
For September in Theni, pack light, breathable clothing and sun protection, with typical highs of 31.2°C and lows of 17.9°C. Bring an umbrella or light rain jacket too.
Relative humidity in September averages 80% — quite humid.
Average wind speed in September is 1.7 m/s. The windiest September on record averaged 2.2 m/s (2016).
The wettest September on record was 1981 with 324 mm. On average, September sees 133 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 Theni 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.
