August so far is a case in point: after a rainy first week, a dry second week pushed the monsoon’s cumulative deficit back to the July 31 level, even as the area under deficient rainfall remains marginally lower. The correlation between El Niño and India’s monsoon rainfall is best assessed at the seasonal scale, meaning a week or two of heavy or deficient rain does not necessarily reflect its impact.
India’s cumulative deficit compared to the 1971-2020 average, which the India Meteorological Department (IMD) considers as the Long Period Average (LPA) for tracking rain’s performance, reached 9%, the lowest it has been since June 5. This happened despite the August surplus at the time being a modest 1.6%. Because august is one of the two rainiest months of the monsoon in the LPA, which leads to even small surpluses in the month mattering more for the cumulative deficit, this is.
The biggest impact of the rain in the first week of August was seen in a decline in the cumulative deficit.
With big deficits, August rain has developed a 10.5% deficit. This has also returned the monsoon’s cumulative deficit to 10.5%, the same level it was on July 31. The final impact of El Niño will only be seen in the final print of the monsoon on September 30, with the current status not very far from the forecast for the season by the IMD.
For example, as HT has reported earlier, even the correlation between El Niño and rainfall is not uniform for all regions of the country. The second week has had the opposite effect. These trends highlight that assessing the overall monsoon situation after a couple of weeks of good or bad rain is not wise. This is especially true of the geographical distribution of rain. It has become weaker over time for central India while remaining relatively stable for northern and southern India.
