The India Meteorological Department (IMD) has updated its forecast for the southwest monsoon, indicating its likely onset over Kerala around June 4. This new timeline marks a slight delay from the usual June 1 start, which traditionally signals the beginning of India's crucial four-month rainy season.
Monsoon Forecast and El Niño Impact
Conditions are now favorable for the monsoon's advance into parts of the Arabian Sea, Lakshadweep Islands, Kerala, Tamil Nadu, and the Bay of Bengal by June 4, according to the IMD. This update follows a recent revision in the weather office's overall forecast for the June-September monsoon season.
The IMD now expects seasonal rainfall across the country to be 90 percent of the long-period average (LPA), a slight reduction from its April projection of 92 percent. The LPA for India's seasonal rainfall, based on data from 1971 to 2020, stands at 87 cm. Mrutyunjay Mohapatra, Director General of Meteorology at the IMD, stated that the monsoon core zone, encompassing most of India's rainfed agriculture areas, is likely to experience below-normal rainfall, specifically less than 94 percent of the LPA. June rainfall nationwide is also predicted to be below normal, under 92 percent of the LPA.
A monsoon season with rainfall below 90 percent of the LPA is officially classified as "deficient." This less optimistic outlook is partly attributed to the transitioning of neutral El Niño-Southern Oscillation conditions in the equatorial Pacific towards El Niño. While El Niño is expected to remain weak in June, it is projected to strengthen to moderate or strong levels by September, a phenomenon typically associated with suppressed monsoon rainfall over India.
Heatwave Warnings and Economic Significance
In addition to the revised monsoon forecast, the IMD has issued warnings for higher temperatures and an increased number of heatwave days during June. Above-normal maximum temperatures are anticipated across most parts of the country. Specifically, many areas in Uttar Pradesh, Haryana, Punjab, Bihar, Odisha, Chhattisgarh, Gujarat, and Andhra Pradesh, along with isolated regions of Maharashtra, are expected to experience above-normal heatwave days.
The arrival of the monsoon over Kerala is a keenly watched event, as it significantly influences rainfall patterns across much of India. Its performance is critical for the nation's agriculture, vital for replenishing water reserves, and holds substantial implications for the broader Indian economy.