Met Éireann has issued a countrywide weather advisory, which will come into effect at 6am on Sunday.
The national forecaster has said Sunday through to Wednesday will be "very cold with temperatures in low single figures by day and with sharp or severe frosts and icy patches at night".
The public has been warned that conditions will be hazardous on roads and paths.
Met Éireann has also said showers of sleet or snow are expected in eastern counties from Sunday evening onwards.
The weather advisory will remain in effect until 6pm on Wednesday.
Temperatures are expected to plummet this weekend with "bitterly cold and wintry" conditions forecast by Met Éireann.
Daytime highs today will reach a maximum of seven degrees, however, moving into tonight temperatures will fall to between -1 and +3 degrees.
Some patches of frost will develop and there will be light to moderate northerly breezes.
Tomorrow will be another cold day with highest afternoon temperatures of 3 to 6 degrees, in light to moderate north to northeast winds.
On Sunday, the national forecaster has said it will be "colder again" with highest temperatures of just 2 to 5 degrees, in a moderate to fresh easterly wind.
Most areas will however stay fully dry albeit cloudy.
Sunday night will be very cold with a widespread frost and ice.
Lowest temperatures will be between -3 to +1 degrees in moderate easterly winds.
Next week, Met Éireann has warned that it will remain "bitterly cold and wintry".
Daytime temperatures on Monday will be between 1 to 3 degrees, whilst nighttime temperatures could dip as low as -3 degrees.
Temperatures on Tuesday will be similar to Monday, but there will be "an added wind-chill factor as easterly winds increase fresh and gusty".
"Wintry showers in the east and near northern coasts at first, but extending to other areas later," Met Éireann has stated.