New Delhi, Jan 16 (IANS): Delhi, Lucknow and Amritsar witnessed dense fog on Saturday morning with zero visibility due to variable and calm lower-level winds, and the fog is likely to persist on Sunday as well.

The Met department said "Zero visibility over Delhi, Lucknow and Amritsar due to variable and calm lower-level winds. Similar fog conditions are likely on the morning of January 17 as well. Visibility is likely to improve from January 18 when a fresh spell of relatively stronger easterlies is likely over north India".

Many flights were delayed and rescheduled. Indigo said in a tweet, "Due to bad weather in Delhi, Bagdogra, Chandigarh and Dibrugarh, flight departures and arrivals are impacted."

The temperatures dipped to 2 degrees Celsius in the national capital as air quality also went down to 'Severe' as per System of Air Quality & Weather Forecasting & Research (SAFAR). Delhi's overall air quality index was at 492.

The Met department said visibility levels dropped to 100 meters at Palam and 201 meters in the national capital. Dense fog added to extreme cold in Jammu & Kashmir on Saturday as the weather office forecast no major change during the next five days in the prevailing weather conditions.

"Morning fog and mist enveloped the plains of Jammu & Kashmir today morning. Weather is likely to improve by late morning. No significant change likely during the next 5 days," an official of the local meteorological department said.

The minimum temperature was minus 8.2 in Srinagar, minus 9.4 in Pahalgam and minus 5.4 in Gulmarg on Saturday. Leh town was at minus 14, Kargil at minus 19 and Drass at minus 25.8 degrees.