May is one of the warmer months of the year in Theni, with average highs near 36.4°C and lows around 20.1°C (mean 28.3°C). It is a relatively wet time of year, averaging 114 mm of rainfall and 70% relative humidity across the period.
May is one of the warmer months of the year in Theni. Across 45 years of records, the warmest May in Theni was 1991 — when the month averaged 30.6°C — while the coldest was 2004 at 26.4°C. Typical May days reach 36.4°C with nights near 20.1°C. The long-term May temperature trend is broadly flat.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 28.2°C | 28.6°C | 28.0°C | 28.2°C | 27.9°C | -0.3°C |
| Avg High | 36.2°C | 37.1°C | 36.3°C | 36.3°C | 35.6°C | -0.6°C |
| Avg Low | 20.2°C | 20.1°C | 19.8°C | 20.1°C | 20.2°C | 0°C |
| Avg Rain | 93 mm | 101 mm | 141 mm | 109 mm | 130 mm | +37 mm |
May temperatures in Theni have fallen by about 0.3°C between 1981–1985 and 2021–2025.
May has ranged from a record low of 17.9°C (2011) to a record high of 39.4°C (1991).
Rainfall in May is a relatively wet time of year, averaging 114 mm, with a wettest year of 394 mm.
Daytime highs and overnight lows have shifted differently — highs fell about 0.2°C per decade while lows rose 0°C per decade, narrowing the gap between day and night.
A quieter season to visit Theni
If your dates are flexible, the more temperate months of January and February tend to be the most comfortable for visiting Theni. That said, May — with days averaging 36.4°C and nights around 20.1°C (mean 28.3°C) and higher rainfall (114 mm) — can still be rewarding for travellers who don't mind the warmth, and often means fewer crowds.
| Year | High | Low | Avg | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|
| 2025 | 33.8°C | 20.9°C | 27.4°C | 138 mm | 75% | 2 m/s | 4.8 |
| 2024 | 38.8°C | 21.2°C | 30.0°C | 193 mm | 72% | 1.3 m/s | 4.7 |
| 2023 | 35.0°C | 20.1°C | 27.6°C | 101 mm | 75% | 1 m/s | 5.7 |
| 2022 | 34.7°C | 19.0°C | 26.9°C | 122 mm | 74% | 1.7 m/s | 5 |
| 2021 | 34.9°C | 19.0°C | 26.9°C | 149 mm | 78% | 1.6 m/s | 5.1 |
| 2020 | 36.3°C | 21.0°C | 28.6°C | 80 mm | 68% | 1.5 m/s | 5.4 |
| 2019 | 38.0°C | 21.4°C | 29.7°C | 34 mm | 61% | 1.3 m/s | 5.7 |
| 2018 | 34.1°C | 20.7°C | 27.4°C | 158 mm | 76% | 1.2 m/s | 5.2 |
| 2017 | 36.8°C | 19.9°C | 28.3°C | 139 mm | 70% | 1.3 m/s | 5.5 |
| 2016 | 38.7°C | 20.3°C | 29.5°C | 121 mm | 69% | 1.6 m/s | 5.4 |
| 2015 | 34.8°C | 19.7°C | 27.3°C | 176 mm | 76% | 1.2 m/s | 5.4 |
| 2014 | 34.5°C | 20.2°C | 27.4°C | 164 mm | 74% | 1.3 m/s | 5.5 |
| 2013 | 37.7°C | 20.4°C | 29.0°C | 59 mm | 64% | 1.7 m/s | 5.6 |
| 2012 | 35.7°C | 19.4°C | 27.5°C | 66 mm | 73% | 1.5 m/s | 5.7 |
| 2011 | 36.4°C | 17.9°C | 27.2°C | 85 mm | 69% | 1.3 m/s | 6.2 |
| 2010 | 36.5°C | 20.9°C | 28.7°C | 86 mm | 70% | 1.6 m/s | 5.5 |
| 2009 | 38.0°C | 20.0°C | 29.0°C | 92 mm | 67% | 1.5 m/s | 5.7 |
| 2008 | 36.2°C | 19.4°C | 27.8°C | 63 mm | 70% | 1.5 m/s | 6.3 |
| 2007 | 36.8°C | 19.5°C | 28.1°C | 72 mm | 68% | 1.5 m/s | 6.2 |
| 2006 | 37.2°C | 20.2°C | 28.7°C | 212 mm | 69% | 1.9 m/s | 5.5 |
| 2005 | 36.4°C | 19.9°C | 28.1°C | 109 mm | 72% | 1 m/s | 5.8 |
| 2004 ❄️ 🌧️ | 33.8°C | 19.0°C | 26.4°C | 394 mm | 84% | 1.8 m/s | 5 |
| 2003 | 36.6°C | 20.4°C | 28.5°C | 117 mm | 72% | 1.8 m/s | 5.7 |
| 2002 | 37.8°C | 20.8°C | 29.3°C | 159 mm | 74% | 1.8 m/s | 5.7 |
| 2001 | 34.5°C | 19.3°C | 26.9°C | 116 mm | 74% | 1.6 m/s | 6 |
| 2000 | 35.9°C | 19.4°C | 27.6°C | 76 mm | 66% | 1.8 m/s | 6.1 |
| 1999 | 36.5°C | 19.1°C | 27.8°C | 180 mm | 77% | 1.7 m/s | 5.3 |
| 1998 | 37.6°C | 20.9°C | 29.2°C | 121 mm | 67% | 1.6 m/s | 5.3 |
| 1997 | 36.7°C | 19.4°C | 28.1°C | 61 mm | 66% | 1.5 m/s | 5.3 |
| 1996 | 37.3°C | 20.1°C | 28.7°C | 23 mm | 64% | 1.2 m/s | 5.5 |
| 1995 | 34.9°C | 19.2°C | 27.0°C | 137 mm | 74% | 1.8 m/s | 5.1 |
| 1994 | 36.3°C | 20.2°C | 28.3°C | 133 mm | 72% | 1.4 m/s | 5.6 |
| 1993 | 38.3°C | 20.4°C | 29.4°C | 96 mm | 66% | 1.4 m/s | 5.6 |
| 1992 | 36.6°C | 20.0°C | 28.3°C | 91 mm | 66% | 1.3 m/s | 5.6 |
| 1991 🔥 | 39.4°C | 21.8°C | 30.6°C | 16 mm | 53% | 1.2 m/s | 5.8 |
| 1990 | 37.2°C | 20.1°C | 28.7°C | 155 mm | 71% | 2.1 m/s | 4.8 |
| 1989 | 36.9°C | 20.3°C | 28.6°C | 99 mm | 67% | 2 m/s | 5.3 |
| 1988 | 36.1°C | 20.4°C | 28.3°C | 54 mm | 69% | 1.8 m/s | 5.5 |
| 1987 | 37.2°C | 20.5°C | 28.8°C | 78 mm | 62% | 1 m/s | 5.9 |
| 1986 | 36.0°C | 19.6°C | 27.8°C | 71 mm | 67% | 1.7 m/s | 5.8 |
| 1985 | 37.8°C | 19.9°C | 28.8°C | 118 mm | 61% | 1.8 m/s | 5.6 |
| 1984 | 35.5°C | 20.4°C | 28.0°C | 58 mm | 68% | 1.6 m/s | 6 |
| 1983 | 37.7°C | 20.7°C | 29.2°C | 51 mm | 62% | 1.3 m/s | — |
| 1982 | 34.0°C | 20.3°C | 27.2°C | 162 mm | 74% | 1 m/s | — |
| 1981 | 34.8°C | 19.7°C | 27.3°C | 150 mm | 73% | 1.4 m/s | — |
Actual recorded May data for each year, 1981–2025 — sourced from NASA POWER.
The average high in May is around 36.4°C with lows near 20.1°C (mean 28.3°C), based on 45 years of NASA POWER data.
May averages 114 mm of rainfall in Theni, a relatively wet time of year. The wettest on record was 394 mm in 2004.
The hottest May reached 39.4°C in 1991. The coldest dipped to 17.9°C in 2011.
Comparing the earliest years on record (1981–1985) with the most recent (2021–2025), average May temperatures have fallen by about 0.3°C. Daytime highs moved from 36°C to 35.4°C and overnight lows from 20.2°C to 20°C over the same span.
May is one of the warmer months of the year in Theni and a relatively wet time of year, so plan for around 36.4°C daytime highs and 20.1°C at night.
Not quite — May is the 11th coolest month in Theni, averaging 28.3°C.
For May in Theni, pack light, breathable clothing and sun protection, with typical highs of 36.4°C and lows of 20.1°C. Bring an umbrella or light rain jacket too.
Relative humidity in May averages 70% — moderately humid.
Average wind speed in May is 1.5 m/s. The windiest May on record averaged 2.1 m/s (1990).
The wettest May on record was 2004 with 394 mm. On average, May sees 114 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 May, 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 May specifically, along with year-by-year records and how the month has changed over the decades.
