Dense fog blanketed parts of the national capital on Wednesday morning, reducing visibility and disrupting over 100 flights and 26 trains.
An official said no flight diversions or cancellations have been reported so far.
"Low visibility and fog over Delhi may lead to some delays. We're keeping a close watch on the weather and doing our best to get you where you need to be , safely and smoothly," IndiGo said in a post on X at 8.18 am.
All runways at IGI Airport are operating under CAT-III conditions, with the Runway Visual Range (RVR) ranging between 75 and 300 metres.
Delhi airport operator DIAL said while landings and takeoffs continue at the airport, flights that are not CAT III-compliant may get affected.
CAT III facility allows flight operations in low visibility conditions.
As per information available on Flightradar24.com, over 100 flights were delayed on Wednesday.
"Passengers are requested to contact the airline concerned for updated flight information. Any inconvenience caused is deeply regretted," Delhi International Airport Ltd (DIAL) said in a post on X at 7.35 am.
The Indira Gandhi International Airport (IGIA) in the national capital handles around 1,300 flight movements daily.
The minimum temperature dropped to 6 degrees Celsius, 1.4 notches below normal, as the city experienced another chilly morning.
The India Meteorological Department (IMD) reported minimum visibility of 200 metres in moderate fog with calm winds at Safdarjung and 150 metres in dense fog with calm winds at Palam around 5:30 am.
The IMD has issued an orange alert for Delhi, with dense to very dense fog reported in several areas. An orange alert is issued for bad weather that can disrupt rail and road services.
It has asked people to exercise caution while driving or travelling during foggy conditions, ensure the use of fog lights for better visibility, and stay updated on schedules by coordinating with airlines, railway authorities, and state transport services to avoid disruptions.
Cloudy skies are expected throughout the day, with light rain or drizzle likely in some areas, the IMD said.
The humidity level at 8.30 am was recorded at 97 per cent while the maximum temperature is expected to settle around 19 degrees Celsius.
