Rainfall in Bengaluru South
Bengaluru South gets 50% of its rain from the monsoon, June to September, and September is its wettest month. In 2025 it got 824 mm, 6% below average (normal).
Month-wise rainfall in Bengaluru South
Average rain in each month, 2006–2025.
| Month | Average rain | Share of the year |
|---|---|---|
| January | 4 mm | 0% |
| February | 4 mm | 0% |
| March | 18 mm | 2% |
| April | 46 mm | 5% |
| May | 127 mm | 15% |
| June | 77 mm | 9% |
| July | 92 mm | 11% |
| August | 132 mm | 15% |
| September | 137 mm | 16% |
| October | 133 mm | 15% |
| November | 75 mm | 9% |
| December | 28 mm | 3% |
Yearly rainfall in Bengaluru South since 2006
Lighter bars are dry years, 20% or more below average (2006, 2011, 2012, 2014, 2016, 2018), when wells and borewells are drawn hardest. The last ten years averaged 16% more rain than the ten before.
What Bengaluru South'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 Bengaluru South sheds about 74,375 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 Bengaluru South?
About 875 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 2022 (1,424 mm) and the driest was 2012 (516 mm).
Which month gets the most rain in Bengaluru South?
September, with 137 mm in an average year, followed by October and August. January is the driest month (4 mm).
How much of Bengaluru South's rain falls in the monsoon?
50% of a normal year's rain falls from June to September. 7 months average 50 mm or more.
How much did it rain in Bengaluru South in 2025?
824 mm, which is 6% below the 2006–2025 average, or "normal" in the India Meteorological Department's terms.
Is rainfall in Bengaluru South increasing or decreasing?
The last 10 years averaged 16% more rain than the 10 before them. Year-to-year swings are still bigger than that change.
How much rainwater can a house in Bengaluru South harvest?
A 100 m² (about 1,076 sq ft) concrete roof in Bengaluru South sheds about 74,375 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 Bengaluru South district. It reads close to, but not exactly the same as, India Meteorological Department rain-gauge totals, and rain varies within a district.