LUCKNOW, May 4 -- A sudden spell of adverse weather across North India on Monday triggered widespread disruption in flight operations, severely impacting services in Lucknow and Delhi. What began as poor visibility and gusty winds in Delhi quickly escalated into a regional aviation disruption, forcing diversions, delays and cancellations. Chaudhary Charan Singh International Airport, Lucknow, became a critical diversion hub, according to a spokesperson for the Lucknow airport.

In all, around 20 flights were delayed during the day, while 15 flights-including three international services-were diverted to Lucknow. Two IndiGo flights on the Abu Dhabi sector were cancelled, disrupting international passenger movement. The cascading impact was...