January is one of the cooler months of the year in Theni, with average highs near 27.4°C and lows around 16.1°C (mean 21.8°C). It is one of the drier months, averaging 19 mm of rainfall and 76% relative humidity across the period.
January is one of the cooler months of the year in Theni. Across 45 years of records, the warmest January in Theni was 2013 — when the month averaged 23.9°C — while the coldest was 1982 at 19.7°C. Typical January days reach 27.4°C with nights near 16.1°C. The long-term January temperature trend is broadly flat.
January is one of the drier months in Theni, averaging 19 mm of rainfall. The wettest January on record was 2021 with 186 mm, while the driest were 1983, 1988 and 1993, among others at 0 mm.
Relative humidity in Theni during January averages 76%. The most humid January was 2021 at 89%, and the least humid was 1990 at 64%.
January receives about 5.2 kWh/m²/day of solar energy in Theni. The sunniest Januarys were 1999, 2008 and 2012, among others at 5.7 kWh/m²/day, and the cloudiest was 2021 at 4.2.
Average wind speed in Theni during January is 1.2 m/s. The windiest Januarys were 2003, 2014 and 2017, among others at 1.4 m/s, while the calmest were 2020, 2022 and 2024, among others at 1.1 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 21.6°C | 21.4°C | 21.8°C | 22.4°C | 21.6°C | 0°C |
| Avg High | 27.3°C | 27.2°C | 27.4°C | 28.5°C | 26.2°C | -1.1°C |
| Avg Low | 16.0°C | 15.6°C | 16.1°C | 16.3°C | 16.9°C | +0.9°C |
| Avg Rain | 29 mm | 14 mm | 11 mm | 8 mm | 46 mm | +16 mm |
January temperatures in Theni have stayed relatively stable across the record.
January has ranged from a record low of 11.6°C (1999) to a record high of 33.6°C (1983).
Rainfall in January is one of the drier months, averaging 19 mm, with a wettest year of 186 mm.
Daytime highs and overnight lows have shifted differently — highs rose about 0°C per decade while lows rose 0.2°C per decade, narrowing the gap between day and night.
One of the best times to visit Theni
January is one of the best times to visit Theni. Expect days averaging 27.4°C and nights around 16.1°C (mean 21.8°C) — cooler than Theni's yearly average — with low rainfall (19 mm), so conditions are generally comfortable for sightseeing and outdoor plans.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 26.2°C | 21.4°C | 16.5°C | 28.6°C | 14.2°C | 21 mm | 82% | 1.3 m/s | 4.6 |
| 2024 | 26.4°C | 21.9°C | 17.4°C | 29.4°C | 15.2°C | 31 mm | 84% | 1.1 m/s | 4.8 |
| 2023 | 26.1°C | 20.8°C | 15.4°C | 28.0°C | 13.2°C | 10 mm | 78% | 1.2 m/s | 5.3 |
| 2022 | 26.1°C | 21.9°C | 17.6°C | 27.8°C | 15.4°C | 21 mm | 85% | 1.1 m/s | 5.2 |
| 2021 🌧️ | 24.7°C | 21.1°C | 17.6°C | 27.0°C | 13.9°C | 186 mm | 89% | 1.3 m/s | 4.2 |
| 2020 | 27.5°C | 22.3°C | 17.0°C | 30.9°C | 14.0°C | 3 mm | 80% | 1.1 m/s | 5.4 |
| 2019 | 29.5°C | 22.4°C | 15.3°C | 32.2°C | 13.2°C | 1 mm | 67% | 1.2 m/s | 5.5 |
| 2018 | 28.0°C | 22.1°C | 16.1°C | 30.3°C | 13.8°C | 5 mm | 72% | 1.1 m/s | 5.1 |
| 2017 | 29.3°C | 22.9°C | 16.4°C | 30.9°C | 13.7°C | 39 mm | 66% | 1.4 m/s | 5 |
| 2016 | 27.4°C | 21.8°C | 16.2°C | 30.0°C | 13.4°C | 1 mm | 78% | 1.1 m/s | 5.4 |
| 2015 | 28.2°C | 22.2°C | 16.1°C | 30.2°C | 13.1°C | 4 mm | 74% | 1.1 m/s | 5.4 |
| 2014 | 28.9°C | 22.8°C | 16.8°C | 30.5°C | 15.2°C | 9 mm | 71% | 1.4 m/s | 5.3 |
| 2013 🔥 | 30.6°C | 23.9°C | 17.2°C | 31.9°C | 15.1°C | 3 mm | 65% | 1.3 m/s | 5.6 |
| 2012 | 28.6°C | 22.2°C | 15.9°C | 30.2°C | 12.4°C | 3 mm | 72% | 1.2 m/s | 5.7 |
| 2011 | 25.4°C | 20.7°C | 16.1°C | 26.9°C | 12.3°C | 5 mm | 84% | 1.3 m/s | 5 |
| 2010 | 28.7°C | 22.8°C | 16.8°C | 30.3°C | 13.7°C | 11 mm | 74% | 1.3 m/s | 5.4 |
| 2009 | 27.6°C | 21.4°C | 15.3°C | 30.7°C | 12.9°C | 7 mm | 75% | 1.3 m/s | 5.6 |
| 2008 | 28.2°C | 21.9°C | 15.6°C | 31.6°C | 13.4°C | 2 mm | 74% | 1.2 m/s | 5.7 |
| 2007 | 26.2°C | 20.9°C | 15.5°C | 28.4°C | 12.7°C | 5 mm | 79% | 1.3 m/s | 5.2 |
| 2006 | 24.6°C | 20.2°C | 15.8°C | 26.1°C | 12.0°C | 20 mm | 84% | 1.2 m/s | 5.1 |
| 2005 | 26.8°C | 21.6°C | 16.3°C | 29.1°C | 13.6°C | 33 mm | 78% | 1.1 m/s | 5.1 |
| 2004 | 28.6°C | 22.5°C | 16.4°C | 31.7°C | 13.4°C | 11 mm | 73% | 1.2 m/s | 5.6 |
| 2003 | 29.1°C | 22.9°C | 16.6°C | 32.1°C | 14.0°C | 4 mm | 70% | 1.4 m/s | 5.2 |
| 2002 | 27.8°C | 22.2°C | 16.6°C | 30.9°C | 12.6°C | 7 mm | 76% | 1.2 m/s | 5.1 |
| 2001 | 27.8°C | 22.2°C | 16.7°C | 30.0°C | 14.2°C | 16 mm | 75% | 1.3 m/s | 4.8 |
| 2000 | 27.3°C | 21.8°C | 16.3°C | 29.8°C | 13.5°C | 12 mm | 75% | 1.4 m/s | 5.1 |
| 1999 | 25.2°C | 20.2°C | 15.1°C | 28.1°C | 11.6°C | 3 mm | 79% | 1.1 m/s | 5.7 |
| 1998 | 26.3°C | 21.5°C | 16.7°C | 28.4°C | 14.1°C | 1 mm | 84% | 1.2 m/s | 5 |
| 1997 | 27.0°C | 21.3°C | 15.6°C | 29.8°C | 12.4°C | 5 mm | 77% | 1.1 m/s | 5.3 |
| 1996 | 28.9°C | 22.2°C | 15.5°C | 30.4°C | 13.1°C | 10 mm | 69% | 1.4 m/s | 5.4 |
| 1995 | 27.6°C | 22.2°C | 16.7°C | 29.9°C | 12.2°C | 23 mm | 76% | 1.2 m/s | 5 |
| 1994 | 24.6°C | 20.3°C | 16.0°C | 26.7°C | 12.5°C | 70 mm | 87% | 1.2 m/s | 5.3 |
| 1993 | 26.2°C | 20.3°C | 14.3°C | 29.6°C | 11.9°C | 0 mm | 75% | 1.3 m/s | 5.2 |
| 1992 | 27.4°C | 20.8°C | 14.2°C | 30.4°C | 12.4°C | 5 mm | 72% | 1.4 m/s | 5.7 |
| 1991 | 29.7°C | 23.3°C | 16.9°C | 32.6°C | 13.4°C | 0 mm | 67% | 1.3 m/s | 5.2 |
| 1990 | 28.7°C | 22.1°C | 15.5°C | 30.8°C | 12.9°C | 24 mm | 64% | 1.4 m/s | 5.4 |
| 1989 | 29.8°C | 23.0°C | 16.2°C | 31.5°C | 13.5°C | 1 mm | 65% | 1.4 m/s | 5 |
| 1988 | 26.0°C | 20.6°C | 15.2°C | 28.5°C | 13.0°C | 0 mm | 80% | 1.2 m/s | 5.6 |
| 1987 | 29.5°C | 22.7°C | 16.0°C | 31.1°C | 12.4°C | 3 mm | 67% | 1.4 m/s | 5.5 |
| 1986 | 27.9°C | 22.5°C | 17.1°C | 31.0°C | 13.8°C | 16 mm | 75% | 1.2 m/s | 5.2 |
| 1985 | 26.3°C | 21.4°C | 16.6°C | 29.5°C | 13.2°C | 122 mm | 80% | 1.2 m/s | 5.1 |
| 1984 | 25.1°C | 21.1°C | 17.2°C | 27.2°C | 14.5°C | 85 mm | 86% | 1.2 m/s | 4.6 |
| 1983 | 29.4°C | 22.4°C | 15.5°C | 33.6°C | 12.6°C | 0 mm | 66% | 1.3 m/s | — |
| 1982 ❄️ | 24.8°C | 19.7°C | 14.6°C | 27.2°C | 13.1°C | 0 mm | 83% | 1.1 m/s | — |
| 1981 | 27.1°C | 21.4°C | 15.7°C | 29.6°C | 14.0°C | 37 mm | 75% | 1.2 m/s | — |
Actual recorded January data for each year, 1981–2025 — sourced from NASA POWER.
The average high in January is around 27.4°C with lows near 16.1°C (mean 21.8°C), based on 45 years of NASA POWER data.
January averages 19 mm of rainfall in Theni, one of the drier months. The wettest on record was 186 mm in 2021.
The hottest January reached 33.6°C in 1983. The coldest dipped to 11.6°C in 1999.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average January temperatures have risen by about 0.2°C — but days and nights have moved in opposite directions. Overnight lows rose from 15.9°C to 16.9°C while daytime highs eased from 26.5°C to 25.9°C, narrowing the gap between day and night.
January is one of the cooler months of the year in Theni and one of the drier months, so plan for around 27.4°C daytime highs and 16.1°C at night.
Not quite — January is the 2nd coolest month in Theni, averaging 21.8°C.
For January in Theni, pack light layers you can adjust through the day, with typical highs of 27.4°C and lows of 16.1°C.
Relative humidity in January averages 76% — quite humid.
Average wind speed in January is 1.2 m/s. The windiest January on record averaged 1.4 m/s (1987).
The wettest January on record was 2021 with 186 mm. On average, January sees 19 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 January, 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 January specifically, along with year-by-year records and how the month has changed over the decades.
