Parts of the country could see snow on Monday night as a severe cold snap sets in.
Met Éireann has updated its weather warning to include the possibility of sleet and snow in Munster overnight. In the North, the UK Met Office has issued a snow and ice warning for all six counties.
The latest high resolution weather models suggest a band of snow travelling across the country from Clare to Waterford on Monday night and into Tuesday morning.
There could also be heavy snow in parts of Ulster and Connacht on Thursday night into Friday morning, but there is still uncertainty over the forecast. The European Centre for Medium-Range Weather Forecasts (ECMRW) is predicting up to 30cm of snow for most of the nine counties of Ulster and Connacht. The Global Forecast System (GFS) is also predicting snow for the same area, in smaller amounts.
A Yellow ice warning for the State comes into force at 6pm on Monday and lasts until 10am on Tuesday.
The cold spell is forecast to set in from the north on Monday evening and spread southwards across the country overnight. Temperatures are expected to fall to between 0 and minus 4 degrees.
Met Éireann is warning of hazardous conditions due to icy stretches on roads and footpaths on Monday night into Tuesday morning.
Temperatures on Tuesday will only rise to between 3 and 6 degrees. However, the wind chill factor will make it feel even colder by an average of four degrees in most places.
There is also a possibility of wintry falls of rain, sleet or snow in parts of the south, though generally it will be relatively dry countrywide throughout the week.
The Road Safety Authority (RSA) has advised that drivers should be aware of the sudden change in weather conditions and be prepared for icy roads.
Met Éireann forecaster Aoife Kealy said any snow is most likely to fall in the southern half of the country, but there is a lot of uncertainty in the forecast.
The cold spell is likely to linger until Friday, with the forecast suggesting a return to milder conditions by the weekend.