The minimum temperature dipped by about two notches in most parts of Punjab, Haryana and Chandigarh with the mercury level hovering between one and three degrees Celsius below normal.
Residents in Ambala woke up to the coldest morning with mercury dropping below 4.5 degrees, three notches below normal.
The border city of Amritsar sizzled at 4.9 degrees, followed by Chandigarh (5), Karnal (6.2) and Ludhiana (6.7).
Besides, several parts of the region such as Bathinda, Adampur, Ambala and Hindon remained engulfed in dense fog. The MET office predicted further fall in the night temperatures in the region on Monday.