Met Eireann are predicting a drop in temperatures and the first winter frosts as conditions are set to cool down in the coming days.
After an unseasonably warm spell for the time of year values are likely to drop significantly.
Expert Alan O'Reilly from Carlow Weather warned that the cold air is set to move over Ireland from Sunday.
He wrote on Wednesday: "Up to 13c today and milder air moving in tomorrow with up to 15c possible, staying mild Friday and into Saturday but turning cooler from Saturday night.
"Highs of just 5c to 7c Sunday with cold air pushing down over Ireland as you can see on animation of upper air temp forecast."
In the meantime we can enjoy the last of a remarkably mild spell of weather with highs of up to 15C expected on Thursday.
A Met Eireann forecaster said: "Thursday will be a dry day, apart from isolated light showers. Staying rather cloudy across western counties, but with some sunny spells elsewhere. Relatively mild with highest temperatures of 12 to 15 degrees Celsius, in mostly moderate southwest breezes.
"It'll be cloudy and misty on Thursday night and still largely dry with just the odd patch of light rain and drizzle. Lowest temperatures of 9 to 11 degrees with fresh southwest winds easing.
"Staying dry and cloudy for Friday with patches of rain and drizzle and some bright spells through the day. Highest temperatures of 11 or 12 degrees in light to moderate southwesterly winds. Outbreaks of rain will reach northwestern coasts towards dawn on Saturday after a fairly dry night. Lowest temperatures of 7 to 10 degrees with moderate southwest winds.
"Dry and bright conditions to start in the south of the country on Saturday. Cloudy conditions with rain in the northwest will move southeastwards through the afternoon with clearer weather with showers following from the north. As the rain clears the southwest winds will veer northwest introducing colder conditions.
"Temperatures in the morning and early afternoon will be between 9 and 12 degrees. Rather cold overnight with scattered showers and moderate to fresh northerly winds. Lowest temperatures of 2 to 5 degrees."
And the first indications of the cold spell will arrive on Sunday with a "widespread frost" overnight, before next week brings colder weather with temperatures "well down" on recent values.
A forecaster added: "Sunday will be a cold and bright day with good sunshine and scattered showers. Afternoon temperatures of between 5 and 7 degrees in moderate northerly winds. Sunday night will be cold with a widespread frost likely as temperatures dip to near freezing or slightly below.
"Current indications suggest colder weather for next week with temperatures well down on recent values with frost at night. It will be mainly dry out to mid-week with sunshine and showers, the showers mainly on coasts."
