Flight and train schedules were disrupted and traffic on highways dropped as fog enveloped more regions of Punjab, Khyber Pakhtunkhwa and upper Sindh on Monday.
Most of flight operations at the Benazir Bhutto International Airport, Islamabad, remained suspended.
The meteorological department forecast cold and dry weather in the central plains of the country for Tuesday.
The Met office forecast that dense foggy conditions were expected to prevail from midnight to midday.
The first flight landed at Islamabad airport at 1:05pm from Karachi. It was followed by PK-792 from Birmingham at 1:25pm. Flights to the Gulf were cancelled.
Railways sources said Pakistan Express, Jaffer Express, Quetta Express and Tezgam arrived in Rawalpindi hours behind schedule. Railcar and Tezgam, however, left Rawalpindi on time.
The maximum temperature in the fog-hit areas of Punjab ranged between eight and 10 degrees centigrade and the same trend is expected to prevail in the coming days.
The motorway portions—M-1 (Peshawar-Islamabad), M2 (Islamabad-Lahore) and M-3 (Pindi Bhattian-Faisalabad)—will remain affected by thick fog during the current week.
Lahore, Gujranwala, Faisalabad, Sargodha, Multan, Bahawalpur and Sukkur divisions remained affected by the thick fog, bringing life to a virtual halt.
The country remained under severe cold and windy conditions and in some places temperature declined to below freezing.
A spokesman for Motorway Police said the M1 (Peshawar to Burhan) was closed for traffic between 4am and 1pm. Visibility on G.T. road from Rawalpindi to Jhelum was negligible throughout the day.
A heavy fog was also reported on the National Highway between Mirpur Mathelo and Sakrand, in Sindh. However, traffic continued at a slow pace.