Tomorrow, showers are expected to become widespread and heavy in the afternoon and evening, with a possibility of hail and thunder.
Highest temperatures of 14 to 17 degrees with moderate northwest winds.
On Wednesday night, showers will continue in many areas with temperatures dipping to about 7 to 9 degrees.
This unsettled weather will continue on Thursday, with Met Éireann stating conditions will be "breezy with sunshine and showers".
Highest temperatures of 14 to 18 degrees with fresh, gusty northeast winds.
"On Friday, showers or longer spells of rain will move in from the east and south and the best of any bright or sunny spells will be in the west," the national forecaster stated.
Highest temperatures will remain in the mid to high teens with moderate to fresh, gusty northeast breezes.
Friday night, there will be further showers or longer spells of rain.
Moving into the weekend, conditions are unlikely to improve.
"Saturday and Sunday will both bring sunny spells and widespread heavy showers, some of hail and thunder," Met Éireann stated.
"Current indications suggest that the early days of next week will continue unsettled with further heavy showers or longer spells of rain and with temperatures in the high teens to low 20s."
All monthly rainfall totals across the country were below their Long-Term Average (LTA) and all available sunshine totals were above their LTA.
Percentage of monthly sunshine values ranged from 127% (monthly sunshine total of 243.9 hours) at Cork Airport to 158% (293.5 hours) at Casement Aerodrome, Co Dublin - its sunniest May on record in 56 years.