Ireland could experience "wintry rain" on Wednesday night as temperatures are set to plunge to 0C.
Met Eireann is forecasting a cold and windy night, with the possibility of heavy rain.
Earlier on Wednesday will see sunny spells and scattered showers. Highs will range from 7C to 9C.
A forecaster said: "Mostly dry on Wednesday with sunny spells, and well scattered showers.
"Cloudier across southern coastal areas with rain moving in here, possibly extending to southern counties later.
"A cool day with highest temperatures of 7 to 9 degrees, in light to moderate southwest breezes."
The national forecaster predicts that rain early on Wednesday night will become widespread.
And the weather chiefs have also warned of heavy rain hitting some areas, as well as "wintry rain". Frost may form as temperatures begin to dip.
The forecaster added: "Outbreaks of rain across southern counties early tonight will become widespread overnight, with some wintry rain possible.
"Some heavy falls will occur with strong winds developing later too. Cold with frost for a time; lowest temperatures of 0 to 3 degrees."
The heavy rain overnight should clear east by Thursday morning.
Rain is not expected by then but it could become misty and foggy.
"Heavy overnight rain across the eastern half of the country, will clear into the Irish Sea through the morning.
"Becoming dry and calm, but rather misty or foggy for a time.
"Later on, a few showers will arrive into the northwest and brisk northwest winds will set in. Feeling cold with highs of just 5 to 8 degrees."
