The India Meteorological Department (IMD) reports that the southwest monsoon's arrival over Kerala has become increasingly variable since 2017 [1].
This unpredictability threatens the stability of Indian agriculture and seasonal planning, as the region relies on the monsoon for approximately 70 percent of its annual rainfall [2].
According to IMD data, the normal average onset date for the monsoon is June 1 [1]. However, over the time span from 2017 to 2026, the actual arrival dates have deviated significantly from this baseline [1]. The earliest recorded onset during this period occurred on May 24 [1]. Conversely, the latest recorded onset was June 8 [1].
These shifts indicate a growing instability in the timing of the rains that travel from Kerala toward Delhi [2]. The IMD said that the onset has become less predictable, creating challenges for weather forecasting and the timing of crop planting.
Climate variability is the primary driver of these erratic patterns. Influences such as El Niño have contributed to the volatility of the onset dates [3]. These atmospheric shifts alter the traditional timing of the seasonal winds, making it difficult for farmers to rely on historical calendars for their sowing cycles.
Because the southwest monsoon provides the bulk of the water supply for the subcontinent, these fluctuations in timing can lead to mismatched planting schedules, or unexpected droughts in the early season [2].
“The southwest monsoon’s arrival over Kerala has become increasingly variable since 2017.”
The increasing variability of the monsoon onset suggests that traditional agricultural calendars are becoming obsolete. As climate drivers like El Niño disrupt established patterns, India faces a higher risk of crop failure and water insecurity if infrastructure and farming techniques do not adapt to a wider window of arrival dates.
