Ireland's cold snap is likely to continue until later in the week, according to Met Éireann's senior forecaster Gerry Murphy.
Mr Murphy told RTÉ's Morning Ireland that fog proved to be the most significant obstacle for drivers on Monday, after Met Éireann confirmed it was the coldest day on record since 2010.
"It was a very foggy day over much of the country. Some places in the south weren't quite as foggy. So visibility was very poor throughout the day.
"In Ballyhaise in Co Cavan the temperature did not rise above minus 3.1 degrees across the day and that was the coldest daytime temperature since 2010, he said.
Mr Murphy said the fog has tended to clear overnight in a large number of areas.
"One significant thing that has improved in many areas is that the fog has tended to clear especially from the Southern half of the country but there are still some very dense patches of fog further to the north, but that is becoming more patchy and will gradually clear through the morning.
Again of course the most significant thing is that it is freezing.
"The lowest temperature overnight was in Ballyhaise in Cavan with minus 6.9 degrees. Temperatures are in general ranging between minus one and minus six degrees. Once again frost and significant ice on the roads. Another morning for taking great care."
Mr Murphy said for most of the country it is going to be another dry day.
Very cold this morning🥶 with any frost, ice❄️ & a few freezing fog patches persisting.
Cloudy in the S with rain in the SW🌧️, possibly falling as sleet/snow🌨️ in some parts inland, leading to hazardous driving conditions.
Drier & brighter elsewhere⛅️.
Highs🌡️ of -1 to +4°C. pic.twitter.com/KvFnyMuW9t
— Met Éireann (@MetEireann) December 13, 2022
"Another very cold day but a dry day. The frost will tend to linger in some places. The fog should clear which means it should brighten up during the day. It will feel quite crisp.
However, in the South of the country it will be cloudier. And in parts of Kerry and Cork you will see rain, sleet and some snow pushing in there to west Cork, south Kerry falling as rain along the coast but further inland some possibility of sleet and snow especially on higher ground."
Mr Murphy added that it will remain very cold over the coming days.
"The night time temperatures are still going to drop to minus 7 possibly minus 8 on a couple of the nights. We don't anticipate that the fog is going to be as much of a problem as it was yesterday. But really for the most part dry but very cold, severe frost and ice on the roads.
Then as you move in to Friday some wintry showers returning to the West. Some rain and sleet possibly for a time on Saturday and at the moment it does look like we will see milder air pushing up on Sunday bringing with it rain and possibly some sleet and snow as well."
Meanwhile, the status yellow warning will remain in place until noon on Friday. Patches of freezing fog persisted overnight leading to hazardous driving conditions in some areas.
A status yellow fog warning is in place for Connacht, Cavan, Donegal, Monaghan, Longford, Louth, Meath, Offaly and Westmeath until 10am on Tuesday.
A status yellow Temperature/Ice warning for Ireland remains in place. It will remain very cold through the week with widespread sharp to severe frosts and icy stretches.
Some showers of hail, sleet and snow will occur, mainly near coasts. Accumulations at lower levels are expected to remain low.
Freezing fog will occur at times, with winds remaining light over land.