{"id":912,"date":"2018-07-13T18:01:09","date_gmt":"2018-07-13T12:31:09","guid":{"rendered":"http:\/\/mol.tropmet.res.in\/?page_id=912"},"modified":"2026-05-21T19:08:42","modified_gmt":"2026-05-21T13:38:42","slug":"monsoon-interannual-timeseries","status":"publish","type":"page","link":"https:\/\/mol.tropmet.res.in\/?page_id=912","title":{"rendered":"Monsoon Interannual Timeseries"},"content":{"rendered":"<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-2793 size-full\" src=\"http:\/\/mol.tropmet.res.in\/images\/\/iitm_aismr_monsoon_enso_1871_2025.png\" alt=\"All India Summer Monsoon Rainfall\" width=\"2400\" height=\"1077\" srcset=\"https:\/\/mol.tropmet.res.in\/images\/iitm_aismr_monsoon_enso_1871_2025.png 2400w, https:\/\/mol.tropmet.res.in\/images\/iitm_aismr_monsoon_enso_1871_2025-300x135.png 300w, https:\/\/mol.tropmet.res.in\/images\/iitm_aismr_monsoon_enso_1871_2025-1024x460.png 1024w, https:\/\/mol.tropmet.res.in\/images\/iitm_aismr_monsoon_enso_1871_2025-768x345.png 768w, https:\/\/mol.tropmet.res.in\/images\/iitm_aismr_monsoon_enso_1871_2025-1536x689.png 1536w, https:\/\/mol.tropmet.res.in\/images\/iitm_aismr_monsoon_enso_1871_2025-2048x919.png 2048w\" sizes=\"auto, (max-width: 2400px) 100vw, 2400px\" \/><\/p>\n<p>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.<\/p>\n<p>Drought years (below -10% departure) are marked in red color and flood years (above 10% departure) are marked in dark blue color. El Ni\u00f1o and La Ni\u00f1a conditions for the summer season are marked using red and blue dots.<\/p>\n<p style=\"padding-left: 40px;\">Download the data for the Monsoon Interannual Timeseries: [<strong><a href=\"https:\/\/web.archive.org\/web\/20260113025138\/http:\/\/mol.tropmet.res.in\/images\/\/iitm_aismr.txt\">iitm_aismr.txt<\/a><\/strong>]<\/p>\n<p>Roxy M. K.\u00a0and\u00a0S. T. Chaithra, 2018: Impacts of Climate Change on the Indian Summer Monsoon.\u00a0<em>Climate Change and Water Resources in India<\/em>, Vimal Mishra, and J. R. Bhatt, Eds., Ministry of Environment Forest and Climate Change, 21-37,\u00a0ISBN: 978-81-933131-6-9 [<a title=\"Impacts of Climate Change on the Indian Summer Monsoon\" href=\"https:\/\/www.rocksea.org\/bin\/research\/roxy_monsoon_review_moef_2018.pdf\" target=\"_blank\" rel=\"noopener noreferrer\">pdf<\/a>].<\/p>\n","protected":false},"excerpt":{"rendered":"<p>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 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-912","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/mol.tropmet.res.in\/index.php?rest_route=\/wp\/v2\/pages\/912","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mol.tropmet.res.in\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/mol.tropmet.res.in\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/mol.tropmet.res.in\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mol.tropmet.res.in\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=912"}],"version-history":[{"count":17,"href":"https:\/\/mol.tropmet.res.in\/index.php?rest_route=\/wp\/v2\/pages\/912\/revisions"}],"predecessor-version":[{"id":2813,"href":"https:\/\/mol.tropmet.res.in\/index.php?rest_route=\/wp\/v2\/pages\/912\/revisions\/2813"}],"wp:attachment":[{"href":"https:\/\/mol.tropmet.res.in\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=912"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}