Long-lead forecast of Indian Summer Monsoon Rainfall (ISMR) (June – September)

(These forecasts are independent of IMD’s forecast. For details refer to the paper mentioned at the end this page)

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All India Forecast for 2021

(Forecasted in October 2020. All values are in mm)

 Homogeneous Monsoon Regions Forecast for 2021

(Forecasted in December 2020. All values are in mm)

Previous Year’s Forecasts and Observed values

(All values are in mm)





·         All India forecast excludes Jammu & Kashmir, Lakshadweep and Andaman & Nicobar Islands.

·         Normal values are as per IMD’s long-period average (LPA).

·         Forecasts for Indian summer monsoon rainfall are obtained using a time-varying model. Details are available in the following paper:

Dutta, R., and R. Maity, (2018), Temporal evolution of hydroclimatic teleconnection and a time-varying model for long-lead prediction of Indian summer monsoon rainfall, Scientific Reports, Nature Publishing Group, 8:10778, Nature Publishing Group, DOI: 10.1038/s41598-018-28972-z

Dutta, R., and R. Maity, (2020), Spatial variation in long-lead predictability of summer monsoon rainfall using a time-varying model and global climatic indices, International Journal of Climatology, Royal Meteorological Society (RMetS), 40(14),5925-5940, doi: 10.1002/joc.6556