LAHORE –Accumulation of dust particles in the atmosphere due to lack of rain, high humidity and decrease in the mercury level is causing mist and fog to set in over the plains of Punjab and Sindh from late night to early morning, hampering vehicular movement in open areas. Temperature in thickly populated localities including Lahore is not that low to allow formation of fog but such was not so in open areas. Increasing pollution level and high humidity has provided favorable conditions for the formation of mist and fog in open areas and suburbs of Lahore when mercury drops considerably from late night to early morning. On Tuesday, maximum and minimum temperature in the City was recorded 26 degree Celsius and 12.5 C respectively. Relative humidity in the morning was recorded as 88 per cent which decreased to 46 per cent in the evening. According to experts, a shallow trough of westerly wave lies over north of the country. Local meteorological department has forecasted mainly dry weather for most parts of the country with mist/fog in the morning over the plains of Sindh and Punjab including the City during the next couple of days.