IndiGo cancelled 57 flights on Saturday and 13 for Sunday, citing "bad weather" and "forecasted bad weather" at various airports. This follows earlier cancellations this month due to pilot duty norms. The airline is operating under DGCA monitoring and a curtailed schedule. The DGCA has designated December 10 to February 10 as the official winter fog window, with specific CAT-IIIB norms for low-visibility landings, impacting operations in northern and eastern India.