Met Éireann has issued a Status Yellow thunderstorm warning for Clare, Kerry and Limerick, in effect from 3pm to 9pm on Wednesday.
Forecasters say thunderstorms are possible in parts of the three counties, bringing the risk of localised flooding, lightning damage and hazardous driving conditions.
It comes as temperatures are expected to climb as high as 28C on Tuesday afternoon as the recent hot, humid, and sunny spell continues.
Met Éireann says this week’s high temperatures may continue into next week.
Meteorologist Siobhán Ryan told RTÉ’s News at One on Monday that, with afternoon temperatures in the mid-20s forecast for the coming days, heatwave conditions could develop.
“The next number of days temperatures will be well above usual, the rest of the we’ll see those mean temperatures coming in around 4C above usual,” she said.
“While there hasn’t been any heatwave per se- a heatwave is when temperatures are in excess of 25C for five days or more — I think actually this current spell of weather, we could see a heatwave develop.”
The forecaster said Tuesday will likely be the warmest day of the week.
Met Éireann expects mist, fog, and isolated coastal showers in the west and southwest to clear by early afternoon, giving way to dry conditions with long periods of sunshine.
Temperatures will range from 22C to 28C in a light easterly breeze.
Tonight, cloudier conditions will develop in the southwest, with possible mist and fog in some areas before dawn.
Temperatures overnight will stay between 13C and 16C in light southerly or variable breezes.
Tomorrow will be warm and humid again, though outbreaks of rain will push up from the southwest as the day progresses, with possible thunderstorms in the west and southwest.
Highest temperatures will range from 21C to 25C in moderate southerly breezes.
On Wednesday night, showers will continue for a time under mostly cloudy skies, with some limited clear spells developing.
Temperatures will remain mild, not falling below 14C to 17C.
Met Éireann says Thursday will start mostly cloudy with scattered showers before long sunny spells develop in the afternoon and evening.
Highest temperatures will be 21C to 25C in light to moderate southwest breezes.
Thursday night will be mostly dry as winds become light and variable, allowing areas of mist and fog to form. Lowest temperatures will range from 10C to 14C.
Finally, Friday will bring more long sunny spells in the afternoon and evening, with light showers easing through the day. Highest temperatures will be 21C to 25C in light easterly or variable breezes.