Met Eireann has issued a Status Yellow weather warning for seven counties.
Every county in Connacht - Galway, Mayo, Roscommon, Sligo and Leitrim - as well as Cavan and Donegal are all affected.
The warning comes into effect at 6pm this evening and is valid until 11am on Monday.
It reads: "Tonight and on Monday morning, wintry showers will bring some accumulations of snow, especially on high ground."
It follows a weather advisory for the whole of Ireland, which was issued by forecasters in Met Eireann yesterday.
The full message reads: "Cold and wintry weather will develop from Sunday evening.
"Showers of hail, sleet and snow will occur in places.
"Snow showers most frequent in Ulster and Connacht and especially so on high ground."
This advisory is still in place until 3pm Tuesday.
There are also two Status Yellow marine warnings.
The gale warning reads: "South to southwest gales developing later today on Irish coastal waters from Mizen Head to Erris Head to Fair Head."
The small craft warning reads: "See gale warning. South or southwest winds of force 6 or 7 at times this morning and again later today on coasts from Fair Head to Carnsore Point to Mizen Head."
