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Rainfall · Tamil Nadu

Rainfall in Nagapattinam

1,225 mmof rain in an average year, 2006–2025

Nagapattinam gets 26% of its rain from the monsoon, June to September, and November is its wettest month. In 2025 it got 1,509 mm, 23% above average (excess).

Novemberwettest month, 299 mm on average
2021wettest year, 1,721 mm
2016driest year, 864 mm
8months a year with 50 mm of rain or more

Month-wise rainfall in Nagapattinam

Average rain in each month, 2006–2025.

0100200300400JanJan: 42 mmFebFeb: 18 mmMarMar: 33 mmAprApr: 48 mmMayMay: 99 mmJunJun: 58 mmJulJul: 62 mmAugAug: 92 mmSepSep: 101 mmOctOct: 208 mmNovNov: 299 mmDecDec: 166 mm
MonthAverage rainShare of the year
January42 mm3%
February18 mm1%
March33 mm3%
April48 mm4%
May99 mm8%
June58 mm5%
July62 mm5%
August92 mm8%
September101 mm8%
October208 mm17%
November299 mm24%
December166 mm14%

Yearly rainfall in Nagapattinam since 2006

Lighter bars are dry years, 20% or more below average (2006, 2012, 2013, 2016), when wells and borewells are drawn hardest. The last ten years averaged 12% more rain than the ten before.

050010001500200020062006: 962 mm2007: 1,043 mm2008: 1,238 mm20092009: 1,111 mm2010: 1,431 mm2011: 1,118 mm20122012: 965 mm2013: 945 mm2014: 1,158 mm20152015: 1,610 mm2016: 864 mm2017: 1,295 mm20182018: 1,011 mm2019: 1,231 mm2020: 1,358 mm20212021: 1,721 mm2022: 1,412 mm2023: 1,235 mm20242024: 1,291 mm2025: 1,509 mm- - average 1,225 mm

What Nagapattinam'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 Nagapattinam sheds about 1,04,125 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?

Water you can put back each year2,08,250 L≈ 21 water tankers of 10,000 L

1 mm of rain on 1 m² is 1 litre. The surface factor allows for water lost to splash, evaporation and first-flush.

Rainwater harvesting cost in NagapattinamGroundwater level in NagapattinamWater quality in Nagapattinam

Frequently asked questions

What is the average annual rainfall in Nagapattinam?

About 1,225 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 (1,721 mm) and the driest was 2016 (864 mm).

Which month gets the most rain in Nagapattinam?

November, with 299 mm in an average year, followed by October and December. February is the driest month (18 mm).

How much of Nagapattinam's rain falls in the monsoon?

26% of a normal year's rain falls from June to September. 8 months average 50 mm or more.

How much did it rain in Nagapattinam in 2025?

1,509 mm, which is 23% above the 2006–2025 average, or "excess" in the India Meteorological Department's terms.

Is rainfall in Nagapattinam increasing or decreasing?

The last 10 years averaged 12% more rain than the 10 before them. Year-to-year swings are still bigger than that change.

How much rainwater can a house in Nagapattinam harvest?

A 100 m² (about 1,076 sq ft) concrete roof in Nagapattinam sheds about 1,04,125 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 Nagapattinam 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