Snowfall overnight and a sharp frost have created hazardous conditions on roads and footpaths overnight.
Parts of the west, northwest and midlands have been seeing the most significant accumulations.
A status yellow warning remains in place for all counties until noon.
Alan O'Reilly from Carlow Weather says it will be very icy this morning.
"The Midlands and East are likely to see accumulations," he said.
"Down to -4 degrees as well though so it will freeze quite readily after that band of snow clears which leads to really icy conditions."