There will be little respite this week from the unseasonably cold weather, according to Met Eireann. "It's not really going to go away," forecaster Ms Jean Byrne told The Irish Times.
The weekend was cold throughout the country with showers of hail, sleet and snow widely reported.
Temperatures ranged from 5C to 9C, plummeting to as low as 2 C after showers.
This week will continue much the same, said Ms Byrne. While it will be "a shade less cold" there will be widespread frost at night and scattered showers, including some wintry hail. There will be sleet, mainly over mountains. There is also a slight risk of thunderstorms.
The bad weather is due to an area of low pressure over Ireland and Britain which is showing no inclination to move away.
Temperatures are very much lower than in a normal April: 5C to 9C compared with a normal 11 C to 14C.
The present cold spell included one night when the weather station at Baldonnel, Co Dublin, recorded its lowest April temperature (5.5C) since its establishment in 1943.