A day after the India Meteorological Department (IMD) issued its first long-range outlook pointing to a below-normal monsoon this year, it warned of a fresh spell of rising temperatures across North-West and Central India over the next four to five days as a ‘heat engine’ in the form of an anticyclone claws its way back.
In contrast, widespread pre-monsoon showers are expected over the North-East and the hills of North-West India, with isolated activity likely over Gujarat and parts of the western peninsula in the ensuing three days. The evolving weather pattern is being closely tracked as meteorologists look for early signals ahead of the informal yet closely watched 40-day window leading up to the monsoon’s onset in June.
Pre-monsoon peak
This period, beginning around April 22, coincides with the so-called pre-monsoon rainfall peak over the Bay of Bengal and the Arabian Sea. It is typically marked by a band of rain-bearing cloud stretching eastward from Kerala into the Bay, a feature that may develop anytime between early April and mid-May.
The timing of the ‘peak’ offers a broad indication of the likely date of monsoon onset over Kerala. In a normal year, when the monsoon sets in around June 1, this cloud band tends to form close to April 21. Thunderstorms heralding the ‘peak’ may close in over parts of the state, and become more organised over the weekend.
Lead up to monsoon
Numerical weather models of the IMD, corroborated by guidance from the European Centre for Medium-Range Weather Forecasts, broadly support this outlook. If trends hold, the monsoon may arrive around its usual time, or marginally earlier, though confirmation will depend on evolution, intensity and spatial spread of thunderstorms.
Satellite imagery on Tuesday evening indicated scattered cloud clusters to the south of Sri Lanka drifting into the Laccadive Sea (Lakshadweep Sea), bounded by Sri Lanka, India and the Maldives. At the same time, a more extensive, lightning-laden mass of thunderstorms was seen building over the south-east Bay of Bengal, as if poised to link up with this cloud band, subject to favourable shifts in the prevailing wind pattern.
Published on April 14, 2026