The 2026 El Niño is expected to produce a below-normal monsoon over North India, potentially reducing rainfall and affecting migratory birds [1, 3].

This atmospheric shift matters because the Indian summer monsoon is critical for agriculture and ecosystem health. The Jacobin cuckoo, known locally as the chatak, relies on the seasonal uplift and environmental cues provided by the rains to time its migration [2, 4].

The India Meteorological Department issued its official monsoon forecast on May 29, 2026 [1]. The agency's projections suggest that the El Niño phenomenon, which alters sea-surface temperatures in the Pacific Ocean, will weaken the monsoon's strength [2, 4]. This typically results in less rainfall across states such as Delhi, Haryana, and Uttar Pradesh [1, 3].

While the IMD forecasts a below-normal season, other analyses suggest the 2026 El Niño could be unpredictable [2]. Some data indicates it may not follow the traditional pattern of producing weaker monsoons, though the risk of reduced precipitation remains a primary concern for the region [2].

To track the progression of the season, the IMD expanded its monitoring ambit to include four eastern states: West Bengal, Bihar, Odisha, and Jharkhand [3]. These additions allow for a more comprehensive view of how the moisture flow is shifting across the subcontinent.

For the Jacobin cuckoo, these changes are more than a meteorological curiosity. The bird's arrival is often seen as a harbinger of the rains, but the actual physical conditions of the atmosphere — specifically the uplift caused by heating and moisture — are what facilitate its journey [2, 4]. A weaker monsoon could disrupt these patterns, potentially altering the timing or success of the migration.

“The 2026 El Niño is expected to produce a below-normal monsoon over North India.”

The intersection of El Niño and avian migration highlights the fragility of biological clocks in the face of climate variability. If the monsoon fails to reach typical levels, it creates a mismatch between the Jacobin cuckoo's migratory instincts and the actual environmental conditions, which can lead to higher mortality rates for migratory species and reduced crop yields for North Indian farmers.