Rainfall in Upper Subansiri
Upper Subansiri gets 70% of its rain from the monsoon, June to September, and July is its wettest month. In 2025 it got 2,125 mm, 3% above average (normal).
Month-wise rainfall in Upper Subansiri
Average rain in each month, 2006–2025.
| Month | Average rain | Share of the year |
|---|---|---|
| January | 11 mm | 1% |
| February | 31 mm | 1% |
| March | 59 mm | 3% |
| April | 167 mm | 8% |
| May | 225 mm | 11% |
| June | 397 mm | 19% |
| July | 421 mm | 20% |
| August | 339 mm | 16% |
| September | 289 mm | 14% |
| October | 113 mm | 5% |
| November | 12 mm | 1% |
| December | 7 mm | 0% |
Yearly rainfall in Upper Subansiri since 2006
Lighter bars are dry years, 20% or more below average (2009, 2011), when wells and borewells are drawn hardest. The last ten years averaged 26% more rain than the ten before.
What Upper Subansiri'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 Upper Subansiri sheds about 1,76,035 litres in an average year, most of it in four monsoon 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 Upper Subansiri?
About 2,071 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 2020 (3,105 mm) and the driest was 2009 (1,548 mm).
Which month gets the most rain in Upper Subansiri?
July, with 421 mm in an average year, followed by June and August. December is the driest month (7 mm).
How much of Upper Subansiri's rain falls in the monsoon?
70% of a normal year's rain falls from June to September. 8 months average 50 mm or more.
How much did it rain in Upper Subansiri in 2025?
2,125 mm, which is 3% above the 2006–2025 average, or "normal" in the India Meteorological Department's terms.
Is rainfall in Upper Subansiri increasing or decreasing?
The last 10 years averaged 26% more rain than the 10 before them. Year-to-year swings are still bigger than that change.
How much rainwater can a house in Upper Subansiri harvest?
A 100 m² (about 1,076 sq ft) concrete roof in Upper Subansiri sheds about 1,76,035 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 Upper Subansiri district. It reads close to, but not exactly the same as, India Meteorological Department rain-gauge totals, and rain varies within a district.