Twenty-seven trains to and from Delhi and several flights were delayed on Monday morning as a thick blanket of fog engulfed the national Capital, ANI reported. The minimum temperature was 8 degrees Celsius, below the season’s average.

The India Meteorological Department announced that the visibility at Safdarjung was 200 metres at 5.30 am but dropped to 100 metres at 8.30 am, according to PTI. At Palam, the visibility was 50 metres between 5.30 am and 8.30 am, leading to the flight disruptions. The minimum visibility required for aircraft to take off is 125 metres.

“Due to fog, some of the flights have been put on hold at the departure points. This has led to a delay,” a Delhi airport official said. “Largely, there have been no diversions or cancellations of flights.” The IMD has forecast clear skies for most of the day.

The air quality in the national Capital was in the “poor” category on Monday. According to the Central Pollution Control Board data, the overall air quality index at noon was 294.