Rainfall in The Nilgiris
The Nilgiris gets 48% of its rain from the monsoon, June to September, and October is its wettest month. In 2025 it got 897 mm, 10% below average (normal).
Month-wise rainfall in The Nilgiris
Average rain in each month, 2006–2025.
| Month | Average rain | Share of the year |
|---|---|---|
| January | 11 mm | 1% |
| February | 6 mm | 1% |
| March | 28 mm | 3% |
| April | 51 mm | 5% |
| May | 122 mm | 12% |
| June | 114 mm | 11% |
| July | 130 mm | 13% |
| August | 122 mm | 12% |
| September | 114 mm | 11% |
| October | 154 mm | 15% |
| November | 108 mm | 11% |
| December | 38 mm | 4% |
Yearly rainfall in The Nilgiris since 2006
Lighter bars are dry years, 20% or more below average (2012, 2016), when wells and borewells are drawn hardest. The last ten years averaged 5% more rain than the ten before.
What The Nilgiris's rain is worth to a building
Every millimetre of rain on a square metre of roof is a litre of water. A 100 m² roof in The Nilgiris sheds about 84,830 litres in an average year, most of it in a few wet months. Sent into a recharge pit, it refills the ground instead of flooding the street.
Your building: how much can you recharge?
1 mm of rain on 1 m² is 1 litre. The surface factor allows for water lost to splash, evaporation and first-flush.
Frequently asked questions
What is the average annual rainfall in The Nilgiris?
About 998 mm a year, averaged over 2006–2025 from NASA POWER satellite and weather-model data for the centre of the district. The wettest year in that time was 2021 (1,393 mm) and the driest was 2016 (545 mm).
Which month gets the most rain in The Nilgiris?
October, with 154 mm in an average year, followed by July and May. February is the driest month (6 mm).
How much of The Nilgiris's rain falls in the monsoon?
48% of a normal year's rain falls from June to September. 8 months average 50 mm or more.
How much did it rain in The Nilgiris in 2025?
897 mm, which is 10% below the 2006–2025 average, or "normal" in the India Meteorological Department's terms.
Is rainfall in The Nilgiris increasing or decreasing?
The last 10 years averaged 5% more rain than the 10 before them. Year-to-year swings are still bigger than that change.
How much rainwater can a house in The Nilgiris harvest?
A 100 m² (about 1,076 sq ft) concrete roof in The Nilgiris sheds about 84,830 litres in an average year: area × rainfall × 0.85 for splash and evaporation. Sent into a recharge pit, that refills the ground under the house instead of running into the drain.
Rainfall from NASA POWER (bias-corrected satellite and weather-model rainfall) at the centre of The Nilgiris district. It reads close to, but not exactly the same as, India Meteorological Department rain-gauge totals, and rain varies within a district.
Rainfall in other districts of Tamil Nadu
- Ariyalur
- Chengalpattu
- Chennai
- Coimbatore
- Cuddalore
- Dharmapuri
- Dindigul
- Erode
- Kallakurichchi
- Kancheepuram
- Kanniyakumari
- Karur
- Krishnagiri
- Madurai
- Mayiladuthurai
- Nagapattinam
- Namakkal
- Perambalur
- Pudukkottai
- Ramanathapuram
- Ranipet
- Salem
- Sivagangai
- Tenkasi
- Thanjavur
- Theni
- Thiruvarur
- Thoothukudi
- Tiruchirappalli
- Tirunelveli
- Tirupathur
- Tiruppur
- Tiruvallur
- Tiruvannamalai
- Vellore
- Villupuram
- Virudhunagar