This is the the second weather warning concerning Galway issued this weekend on top of a snow ice warning covering Sunday night and Monday morning.
The Met Office says the conditions could make "some roads and railways likely to be affected with longer journey times by road, bus and train services" and people to suffer "some injuries from slips and falls on icy surfaces".
According to Met Eireann's forecast for the coming days, tonight will be blustery with clear spells and occasional showers. Highest temperatures of 4 to 7 degrees with fresh to strong, gusty westerly winds and with gales on coasts. However, persistent rain will develop in the southwest in the late afternoon and spread over Munster and south Leinster.
"Bitterly cold polar air will dig down across over Ireland.It will turn bitterly cold everywhere tomorrow with that polar air established over the country bringing frequent showers of hail, sleet and even snow".More news: Pochettino slams "arrogant" Tottenham after loss to Southampton
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"That is likely through the early hours of the morning towards dawn as this system moves away into the North Sea".
Met Office meteorologist John West said a low pressure system will see heavy rain push into Northern Ireland, England and Wales overnight and into Sunday morning. After another brief respite later Wednesday, further wet and windy weather is expected for Thursday and Friday.
Scattered thunderstorms will also occur.