Met Eireann has issued a weather warning this evening as "dense fog" is expected to cross 23 counties.
Most of Ireland is expected to be blanketed in fog, with all of Munster, Leinster and Connacht affected.
Donegal, Cavan and Monaghan as well as counties in Northern Ireland are unaffected.
The Status Yellow weather warning, issued at 3pm on Sunday and valid until 6am on Monday, reads: "Fog thickening this evening, with some dense areas of fog this evening and tonight."
There is also a small craft warning in place, issued at 1pm on Sunday, which reads: "Westerly winds will reach force 6 or higher tonight (Sunday night) on Irish coasts from Slyne Head to Rossan Point to Fair Head."
Tonight's national forecast from Met Eireann states it will be "cloudy and mostly dry at first".
It adds: "Light rain and drizzle rain will move southeastwards across Ulster overnight, to lie across the northern half of the country by morning. Mist and fog becoming widespread through Munster, Connacht and Leinster tonight also. Lowest temperatures of 4 to 8 degrees in light to moderate west to southwest winds."
The forecast for tomorrow, Monday, reads: "Tomorrow will be cloudy with outbreaks of rain and drizzle, most persistent in the northwest. Much of Munster will be dry, with some brighter intervals here. Highest temperatures of 9 to 11 degrees with light to moderate westerly winds."
And ahead, we can expect cloud and rain along with colder temperatures as we enter December: "The beginning of the week will be mostly cloudy with some rain or drizzle at times and temperatures will be average for the time of year. Turning much colder and more unsettled from midweek."
