Met Eireann's advising people to expect severe thunderstorms throughout the country later today.
It has issued a yellow weather warning for the 26 counties, and a similar alert's in place in the North.
The warnings will start from 4 o'clock this afternoon and will be in place until tomorrow morning.
Cathal Nolan, from Ireland's Weather Channel, says there could be spot flooding.
"Certainly in terms of thunderstorms it could be quite severe, the environmental conditions are all in place for the development of some quite strong thunderstorms throughout the afternoon and evening.
"It seems as though western parts will see the brunt of those storms, breaking out about 4pm onwards, and probably peaking through the evening hours.
"With that there could be some frequent lightening, hailstones, and indeed spot flooding could be an issue in or two locations too."
