A Status Yellow snow and ice warning has been issued in addition to the Status Yellow wind warning already in effect, while a rain warning expired at 3pm.
Met Éireann said that showers may fall as sleet or snow with some accumulations possible, mainly on high ground.
The warning will be in effect from 9pm this evening until 9am tomorrow for Cork, Kerry, Limerick, Tipperary, Waterford, Donegal, Galway, Leitrim, Mayo, Sligo and Wicklow.
The forecaster cautioned that temperatures are expected to drop to between 0C and 3C, with surface water from today's heavy rain likely to freeze quickly, leading to icy stretches on untreated roads and footpaths.
Even in counties not covered by the warning, Met Éireann has advised caution due to "hazardous" driving conditions and slippery footpaths, while advising that scattered blustery showers of hail and sleet may continue throughout the night.
It also warns that strong and gusty southwesterly winds could lead to difficult travelling conditions, debris or loose objects displaced and fallen branches or trees. The wind warning is in place until 6pm.
Travel disruption
Irish Ferries said some sailings between Dublin and Holyhead were cancelled today, including the 7.30am sailing from Dublin and the 1.15pm sailing from Holyhead.
There has also been some disruption to flights at Dublin Airport. Eight inbound aircraft had to perform "go-arounds", while three inbound flights had to be diverted to other airports.
"As always, passengers should contact their airline directly for latest updates on the status of their flight," the daa said on X.
A spokesperson for Shannon Airport said that it had facilitated diversions from both Cork and Dublin airports, with passengers being transferred by coach to their original destinations.
A Status Yellow rain warning that was in place for 21 counties expired at 3pm.
It covered Cavan, Donegal, Monaghan, Clare, Kerry, Limerick, Tipperary, Dublin, Kildare, Laois, Longford, Louth, Meath, Offaly, Westmeath, Wicklow and all of Connacht.
A Yellow wind warning which was issued for counties Antrim, Armagh, Derry, Down, Fermanagh and Tyrone by the UK Met Office expired at noon.
Conditions 'routine March weather' - Met Éireann
Met Éireann forecaster Siobhán Ryan said a change in air mass is already occurring and "the winds have veered westerly in direction."
"When they begin to veer westerly, we know that that change in air mass has already occurred, so the temperatures … are falling back quite markedly in across the north and west," she said, and added that the temperature will also fall "quite dramatically" in the coming hours in the south and east.
Ms Ryan said tonight will be cold and "the temperatures might come in around 0C to [plus] 3C overnight, but it's going to feel colder, because obviously there's going to be a wind-chill factor … so that's going to steer down some sleet and snow showers".
However, Ms Ryan described the conditions as "routine March weather," and the temperature would rise a "little bit" over the weekend but "there's still going to be a little edge on it".
She said Saturday would likely be a better day than Sunday, with "long dry spells" on Saturday and the return of a "wind-chill factor" on Sunday.
She said it would remain changeable into next week, and for St Patrick's Day, "maybe a bit cloudy, not so cold, but probably a spell of rain at some stage".
Beyond that, "there are tentative signs of high pressure building," she said.
Ms Ryan said "anything goes" with St Patrick's Day weather, "it can be dry and sunny, the most you can hope for is temperatures in the high teens at the very, very best.
"But you can also experience temperatures in the low single figures … and I think for this St Patrick's Day it's going to be somewhere in between those," she added.
