May is one of the warmer months of the year in Theni, with average highs near 32.3°C and lows around 21.8°C (mean 27.1°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 29.7°C — while the coldest was 2004 at 24.4°C. Typical May days reach 32.3°C with nights near 21.8°C. The long-term May temperature trend is broadly flat.
May is a relatively wet time of year in Theni, averaging 114 mm of rainfall. The wettest May on record was 2004 with 394 mm, while the driest was 1991 at 16 mm.
Relative humidity in Theni during May averages 70%. The most humid May was 2004 at 84%, and the least humid was 1991 at 53%.
May receives about 5.5 kWh/m²/day of solar energy in Theni. The sunniest May was 2008 at 6.3 kWh/m²/day, and the cloudiest was 2024 at 4.7.
Average wind speed in Theni during May is 1.5 m/s. The windiest May was 1990 at 2.1 m/s, while the calmest were 1987, 2005 and 2023, among others at 1 m/s.
Ranked against the other 11 months using 1981–2025 averages.
| Metric | 1980s | 1990s | 2000s | 2010s | 2020s | Change |
|---|---|---|---|---|---|---|
| Avg Temp | 27.2°C | 27.3°C | 26.7°C | 27.1°C | 26.8°C | -0.4°C |
| Avg High | 32.8°C | 32.7°C | 31.7°C | 32.2°C | 31.6°C | -1.2°C |
| Avg Low | 21.6°C | 21.8°C | 21.6°C | 22.1°C | 22.0°C | +0.4°C |
| Avg Rain | 93 mm | 101 mm | 141 mm | 109 mm | 130 mm | +37 mm |
May temperatures in Theni have fallen by about 0.5°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 0.3°C per decade while lows rose 0.1°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 December tend to be the most comfortable for visiting Theni. That said, May — with days averaging 32.3°C and nights around 21.8°C (mean 27.1°C) and higher rainfall (114 mm) — can still be rewarding for travellers who don't mind the warmth, and often means fewer crowds.
| Year | Avg High | Avg Temp | Avg Low | Hottest Day | Coldest Day | Rainfall | Humidity | Wind | Solar |
|---|---|---|---|---|---|---|---|---|---|
| 2025 | 30.6°C | 26.5°C | 22.4°C | 33.8°C | 20.9°C | 138 mm | 75% | 2 m/s | 4.8 |
| 2024 | 32.5°C | 27.8°C | 23.1°C | 38.8°C | 21.2°C | 193 mm | 72% | 1.3 m/s | 4.7 |
| 2023 | 31.3°C | 26.5°C | 21.7°C | 35.0°C | 20.1°C | 101 mm | 75% | 1 m/s | 5.7 |
| 2022 | 31.4°C | 26.2°C | 21.0°C | 34.7°C | 19.0°C | 122 mm | 74% | 1.7 m/s | 5 |
| 2021 | 30.5°C | 25.8°C | 21.1°C | 34.9°C | 19.0°C | 149 mm | 78% | 1.6 m/s | 5.1 |
| 2020 | 33.2°C | 27.9°C | 22.7°C | 36.3°C | 21.0°C | 80 mm | 68% | 1.5 m/s | 5.4 |
| 2019 | 35.0°C | 29.1°C | 23.3°C | 38.0°C | 21.4°C | 34 mm | 61% | 1.3 m/s | 5.7 |
| 2018 | 30.6°C | 26.3°C | 21.9°C | 34.1°C | 20.7°C | 158 mm | 76% | 1.2 m/s | 5.2 |
| 2017 | 32.5°C | 27.4°C | 22.2°C | 36.8°C | 19.9°C | 139 mm | 70% | 1.3 m/s | 5.5 |
| 2016 | 32.7°C | 27.5°C | 22.4°C | 38.7°C | 20.3°C | 121 mm | 69% | 1.6 m/s | 5.4 |
| 2015 | 30.5°C | 25.9°C | 21.3°C | 34.8°C | 19.7°C | 176 mm | 76% | 1.2 m/s | 5.4 |
| 2014 | 31.2°C | 26.4°C | 21.6°C | 34.5°C | 20.2°C | 164 mm | 74% | 1.3 m/s | 5.5 |
| 2013 | 33.0°C | 27.7°C | 22.4°C | 37.7°C | 20.4°C | 59 mm | 64% | 1.7 m/s | 5.6 |
| 2012 | 31.2°C | 26.4°C | 21.7°C | 35.7°C | 19.4°C | 66 mm | 73% | 1.5 m/s | 5.7 |
| 2011 | 33.0°C | 27.2°C | 21.3°C | 36.4°C | 17.9°C | 85 mm | 69% | 1.3 m/s | 6.2 |
| 2010 | 32.5°C | 27.4°C | 22.4°C | 36.5°C | 20.9°C | 86 mm | 70% | 1.6 m/s | 5.5 |
| 2009 | 32.7°C | 27.3°C | 22.0°C | 38.0°C | 20.0°C | 92 mm | 67% | 1.5 m/s | 5.7 |
| 2008 | 32.0°C | 26.6°C | 21.2°C | 36.2°C | 19.4°C | 63 mm | 70% | 1.5 m/s | 6.3 |
| 2007 | 33.1°C | 27.4°C | 21.6°C | 36.8°C | 19.5°C | 72 mm | 68% | 1.5 m/s | 6.2 |
| 2006 | 32.0°C | 27.0°C | 21.9°C | 37.2°C | 20.2°C | 212 mm | 69% | 1.9 m/s | 5.5 |
| 2005 | 32.2°C | 27.0°C | 21.8°C | 36.4°C | 19.9°C | 109 mm | 72% | 1 m/s | 5.8 |
| 2004 ❄️ 🌧️ | 28.3°C | 24.4°C | 20.6°C | 33.8°C | 19.0°C | 394 mm | 84% | 1.8 m/s | 5 |
| 2003 | 31.9°C | 27.0°C | 22.0°C | 36.6°C | 20.4°C | 117 mm | 72% | 1.8 m/s | 5.7 |
| 2002 | 31.6°C | 26.6°C | 21.7°C | 37.8°C | 20.8°C | 159 mm | 74% | 1.8 m/s | 5.7 |
| 2001 | 31.0°C | 26.1°C | 21.2°C | 34.5°C | 19.3°C | 116 mm | 74% | 1.6 m/s | 6 |
| 2000 | 32.6°C | 27.1°C | 21.6°C | 35.9°C | 19.4°C | 76 mm | 66% | 1.8 m/s | 6.1 |
| 1999 | 29.6°C | 25.2°C | 20.8°C | 36.5°C | 19.1°C | 180 mm | 77% | 1.7 m/s | 5.3 |
| 1998 | 33.7°C | 28.2°C | 22.6°C | 37.6°C | 20.9°C | 121 mm | 67% | 1.6 m/s | 5.3 |
| 1997 | 32.7°C | 27.1°C | 21.5°C | 36.7°C | 19.4°C | 61 mm | 66% | 1.5 m/s | 5.3 |
| 1996 | 34.4°C | 28.1°C | 21.8°C | 37.3°C | 20.1°C | 23 mm | 64% | 1.2 m/s | 5.5 |
| 1995 | 30.8°C | 25.9°C | 21.1°C | 34.9°C | 19.2°C | 137 mm | 74% | 1.8 m/s | 5.1 |
| 1994 | 31.9°C | 26.8°C | 21.7°C | 36.3°C | 20.2°C | 133 mm | 72% | 1.4 m/s | 5.6 |
| 1993 | 33.5°C | 27.7°C | 22.0°C | 38.3°C | 20.4°C | 96 mm | 66% | 1.4 m/s | 5.6 |
| 1992 | 33.5°C | 27.6°C | 21.6°C | 36.6°C | 20.0°C | 91 mm | 66% | 1.3 m/s | 5.6 |
| 1991 🔥 | 36.0°C | 29.7°C | 23.5°C | 39.4°C | 21.8°C | 16 mm | 53% | 1.2 m/s | 5.8 |
| 1990 | 31.2°C | 26.4°C | 21.6°C | 37.2°C | 20.1°C | 155 mm | 71% | 2.1 m/s | 4.8 |
| 1989 | 32.7°C | 27.1°C | 21.5°C | 36.9°C | 20.3°C | 99 mm | 67% | 2 m/s | 5.3 |
| 1988 | 32.9°C | 27.3°C | 21.8°C | 36.1°C | 20.4°C | 54 mm | 69% | 1.8 m/s | 5.5 |
| 1987 | 33.7°C | 27.8°C | 21.8°C | 37.2°C | 20.5°C | 78 mm | 62% | 1 m/s | 5.9 |
| 1986 | 33.0°C | 27.3°C | 21.5°C | 36.0°C | 19.6°C | 71 mm | 67% | 1.7 m/s | 5.8 |
| 1985 | 33.7°C | 27.7°C | 21.8°C | 37.8°C | 19.9°C | 118 mm | 61% | 1.8 m/s | 5.6 |
| 1984 | 33.0°C | 27.1°C | 21.2°C | 35.5°C | 20.4°C | 58 mm | 68% | 1.6 m/s | 6 |
| 1983 | 33.9°C | 28.1°C | 22.3°C | 37.7°C | 20.7°C | 51 mm | 62% | 1.3 m/s | — |
| 1982 | 31.3°C | 26.2°C | 21.1°C | 34.0°C | 20.3°C | 162 mm | 74% | 1 m/s | — |
| 1981 | 31.2°C | 26.2°C | 21.1°C | 34.8°C | 19.7°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 32.3°C with lows near 21.8°C (mean 27.1°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 0.5°C — but days and nights have moved in opposite directions. Overnight lows rose from 21.5°C to 21.9°C while daytime highs eased from 32.6°C to 31.3°C, narrowing the gap between day and night.
May is one of the warmer months of the year in Theni and a relatively wet time of year, so plan for around 32.3°C daytime highs and 21.8°C at night.
Not quite — May is the 11th coolest month in Theni, averaging 27.1°C.
For May in Theni, pack light, breathable clothing and sun protection, with typical highs of 32.3°C and lows of 21.8°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.
