Temperature's are due to become as low as -5degrees.
A status 'yellow' low temperature / ice warning has been extended for the whole country until Thursday.
Other Status Orange and Status Yellow alerts for snow and rain, remain in place until this evening.
Counties worst affected by snow overnight include Limerick, Tipperary, Kilkenny, Carlow, Laois - and Wicklow - from where
Alex Rowley reports: