Monsoon Interannual Timeseries

All India Summer Monsoon Rainfall

The All-India area-weighted mean summer monsoon rainfall (AISMR), based on a homogeneous rainfall data set of 306 rain gauges in India, developed by the Indian Institute of Tropical Meteorology, is widely considered as a reliable index of summer monsoon activity over the Indian region. The time series evolution of AISMR anomalies is expressed as percentage departures from its long-term mean over 1871-2020.

Drought years (below -10% departure) are marked in red color and flood years (above 10% departure) are marked in dark blue color. El Niño and La Niña conditions for the summer season are marked using red and blue dots.

Download the data for the Monsoon Interannual Timeseries: [iitm_aismr.txt]

Roxy M. K. and S. T. Chaithra, 2018: Impacts of Climate Change on the Indian Summer Monsoon. Climate Change and Water Resources in India, Vimal Mishra, and J. R. Bhatt, Eds., Ministry of Environment Forest and Climate Change, 21-37, ISBN: 978-81-933131-6-9 [pdf].