Ireland is set to experience some unusual conditions on Monday ahead of a big change before Christmas.
Met Eireann has issued a Status Yellow fog warning for the entire country which will be in effect until 11am.
The weather forecaster is warning that fog patches will be dense in some areas, giving reduced visibility and poor driving conditions.
The alert comes before the arrival of a cold snap in the days before Christmas.
A Met Eireann meteorologist says conditions will turn colder over the festive weekend, with a white Christmas not being ruled out.
Meteorologist Deirdre Lowe said: “It’s still too early to say with certainty what weather we can expect on Christmas Day. At the moment it looks like the current blocking high pressure will be replaced by low pressure, increasing the chance of unsettled weather.
"There are also some early signs of a possible cold spell over the Christmas period but it’s still very uncertain, so keep an eye on the latest Met Eireann forecast.”
Before then, Monday will be a rather dull day with mist and fog gradually clearing through the morning and just a few brighter spells in places.
Whilst most areas will remain dry, a little patchy drizzle is possible. Highest temperatures of 5 to 9C.
A forecaster said: "Cloudy and mostly dry tonight with some mist and fog in places. A few spots of drizzle possible too. A touch of frost forming locally under any clear spells. Lowest temperatures generally of 2 to 5C, locally colder under any clear spells, in light or moderate southeasterly winds.
"Continuing mostly dry and cloudy for tomorrow, Tuesday with a few brighter spells locally. Risk of a few spots of drizzle too. Highest temperatures of 5 to 8C in mostly moderate southeasterly winds, fresher near Atlantic coasts.
"Continuing mostly cloudy on Tuesday night, with rain extending into the west and southwest overnight accompanied by strengthening southeast winds. Lowest temperatures of 3 to 6C, coldest over Ulster.
"The rain will spread countrywide on Wednesday morning. Drier conditions will follow for a time in the afternoon but with more rain likely again in the evening and early night. It will be a bit milder on Wednesday with highest temperatures of 9 to 12C."
The forecaster added: "Any lingering overnight rain in the northeast will clear on Thursday morning to give drier conditions apart from a little drizzle. Some brighter spells will develop and it will be quite mild with highest temperatures of 10 to 12C.
"Friday, Christmas eve, will bring rain at times in light to moderate east to southeast breezes. A bit colder with highs of 7 to 9C.
"At the moment, Christmas day looks like bringing some further rain at times but dry periods too. Highest temperatures around 5 to 9C (coldest over north Ulster with some sleet possible on hills).
"The further outlook period will probably gradually turn colder."
