MORE hail, sleet and snow are expected in parts of the country this week after a white start to St Patrick's Day.
Forecasters ruled out a quick return to spring weather following a mild spell last week.
Wintry conditions swept the country yesterday. Met Eireann predicted that temperatures tonight would be sub zero, and as low as minus three degrees in places.
Meteorologist Harm Luijkx said the icy conditions on St Patrick's Day had been worse than expected.
And he said it was going to stay cold until at least mid-week, with a constant threat of prolonged showers.
"It looks like today will be mostly rain and some sleet, but then as we go through the evening, it will become colder."
He said it would become increasingly wintry during the week, with some snow likely, mainly in Ulster and north Leinster this evening.
"It won't necessarily be disruptive," he added.
He said snow would be mostly in the north midlands and north Leinster tomorrow, and temperatures were likely to be several degrees below freezing in many areas.
"Tonight and Tuesday will bring quite extreme weather for this time of year," he said.
However, it is not all bad news, and Thursday is set to get gradually milder as wet and windy weather spreads from the south of the country.
Forecasters believe there has only been snow on two or three occasions in the past 20 years on St Patrick's Day.
Meanwhile, two teenage boys were treated for mild hypothermia after getting into difficulty off the coast of Greystones in Wicklow. They became trapped on rocks by the incoming tide near the La Touche Hotel yesterday and were airlifted by the coast guard to Tallaght Hospital.