Four southern counties are under a status orange rain warning this afternoon as Met Éirean issues a warning that "heavy rain" may cause minor flooding.
The Orange warning is in effect from noon until five o'clock in the counties of Cork, Tipperary, Kilkenny, and Waterford.
For the duration of this Halloween Monday, a Status Yellow rainfall warning is in effect for the rest of the nation including Northern Ireland.
According to Met Éireann, today's heavy rain will cause some disruption and localised floods.
Through this afternoon, there will be widespread heavy and sometimes thunderous downpours across the western half of the country, with heavy falls also occurring in Munster and south Leinster.
Beginning at 2 pm and lasting through the evening, there will be moderate rain in eastern areas, including Dublin.
Rain in eastern counties will stop later tonight, then there will be clear spells and a few scattered showers.