Outbreaks of rain in many areas at first, with some sleet and snow in parts of the north and northwest, but clearer conditions will extend from the west during the morning.
It will brighten gradually, with sunny spells developing, but some scattered showers will develop also, mainly in Atlantic coastal areas at first, extending further east later.
Mild at first, except in the north and northwest, but turning cold, with maximum afternoon temperatures 5 to 9 Celsius.
Windy, with fresh to strong and gusty mainly southwest winds, veering west to northwest.
Tonight will be very cold, with clear spells and scattered showers, most of the showers in the western half of the country, turning increasingly wintry as the night progresses, with some hail and sleet.
There is a risk of snow showers also, especially over high ground and a risk of thunder, mainly on northwest coasts.
Minimum temperatures 0 to 4 Celsius, with frost in sheltered places.
Winds mostly moderate to fresh westerly winds.
National weather warning
A status yellow rainfall warning reamins in effect for Connacht, Cavan, Monaghan, Donegal, Dublin, Kildare, Laois, Longford, Louth, Wicklow, Offaly, Westmeath, Meath, Clare, Limerick and Tipperary.
Rain overnight into Monday has seen accumulations forecast of between 20 to 25mm, with higher totals possible in upland areas.
The rain is likely to be preceded by a period of sleet and snow in parts of Connacht, Ulster and north Leinster - with hazardous driving conditions for a time - before turning to rain later.
As the ground is saturated at the moment and river levels are elevated, the combined effect of rainfall and snow melt may lead to some localised surface and river flooding.
The alert is in place until 8.00am.