New Delhi, Jan 6  The mercury dropped to the season’s lowest at 4.2 degrees Celsius in the national capital today even as dense fog continued to disrupt rail and air traffic.

According to MeT department, the maximum temperature was recorded at 20.8 degree Celsius, a notch below the season’s average.

The minimum temperature was 4.2 degree Celsius, three notches below the season’s average.

At the Safdarjung observatory, visibility was recorded at 300 meters at 8.30 am, while during the same period, it was 50 meters at Palam observatory.

Due to poor visibility, the Railways had to cancel 36 trains, reschedule 30 while 85 trains were running late.

The Met department recorded 100 per cent relative humidity at 8.30 am.