Rainfall in Aizawl
Aizawl gets 61% of its rain from the monsoon, June to September, and June is its wettest month. In 2025 it got 2,111 mm, 30% above average (excess).
Month-wise rainfall in Aizawl
Average rain in each month, 2006–2025.
| Month | Average rain | Share of the year |
|---|---|---|
| January | 8 mm | 0% |
| February | 19 mm | 1% |
| March | 52 mm | 3% |
| April | 134 mm | 8% |
| May | 241 mm | 15% |
| June | 293 mm | 18% |
| July | 264 mm | 16% |
| August | 249 mm | 15% |
| September | 188 mm | 12% |
| October | 142 mm | 9% |
| November | 25 mm | 2% |
| December | 14 mm | 1% |
Yearly rainfall in Aizawl since 2006
Lighter bars are dry years, 20% or more below average (2006, 2007, 2008, 2009, 2014), when wells and borewells are drawn hardest. The last ten years averaged 37% more rain than the ten before.
What Aizawl'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 Aizawl sheds about 1,38,380 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 Aizawl?
About 1,628 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 2017 (2,785 mm) and the driest was 2006 (852 mm).
Which month gets the most rain in Aizawl?
June, with 293 mm in an average year, followed by July and August. January is the driest month (8 mm).
How much of Aizawl's rain falls in the monsoon?
61% of a normal year's rain falls from June to September. 8 months average 50 mm or more.
How much did it rain in Aizawl in 2025?
2,111 mm, which is 30% above the 2006–2025 average, or "excess" in the India Meteorological Department's terms.
Is rainfall in Aizawl increasing or decreasing?
The last 10 years averaged 37% more rain than the 10 before them. Year-to-year swings are still bigger than that change.
How much rainwater can a house in Aizawl harvest?
A 100 m² (about 1,076 sq ft) concrete roof in Aizawl sheds about 1,38,380 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 Aizawl district. It reads close to, but not exactly the same as, India Meteorological Department rain-gauge totals, and rain varies within a district.