At least 25 trains and around 50 flights experienced delays as Delhi grappled with the season's most severe fog on Wednesday. The thick fog reduced visibility to merely 50 meters in Safdarjung and Palam, impacting transportation. Northern Railways reported delays of over an hour, with major trains like Puri-New Delhi Purushottam Express and Howrah-New Delhi Poorvah Express running more than five hours behind schedule. Flights, although not diverted, faced delays as visibility dropped. The India Meteorological Department highlighted the unprecedented thickness of the fog, lasting longer than the previous day.

The Air Quality Index (AQI) in Delhi rose to 380 (very poor) at 9 am, indicating a likely deterioration to the severe category. The IMD predicts a persistent severe AQI until Friday, with temperatures expected to reach 22°C. Despite a temporary improvement on Monday, Delhi's air quality remains a concern, exacerbated by the ongoing El Nino weather phenomenon, keeping daytime temperatures higher.