Met Éireann has issued a Status Yellow thunderstorm warning until 9pm on Tuesday for parts of Ulster, Munster, and Leinster, including Cavan, Donegal, Leitrim, Carlow, Cork, Tipperary, Kilkenny, Waterford, Wicklow, and Wexford.
The weather service added that there was potential for heavy rainfall and some localised flooding.
Meanwhile, a high temperature warning remains in place across Leinster until 7pm, with highs of between 22C to 28C expected.
It will be cooler in other parts of the country, with highs of between 16 to 22 degrees.
Met Éireann has advised anyone heading outdoors to wear suncream, hats, and sunglasses, with moderate UV levels between 3-5.
Rain is also expected across the east and south overnight, with the rest of the country remaining drier despite a few isolated showers.
Pollen levels will range from moderate to high across the country, with the worst levels seen in Leinster and Munster.
Despite the warnings, the weather has been welcomed by sun-worshippers in the capital.
Suzanne Moore, who is from Dublin originally but now lives in the US state of Connecticut, told the PA news agency that she welcomed the hot weather.
“I think it’s fantastic – shorts and a top on a Tuesday, you can’t beat it,” she said.
“I packed a sweater, I haven’t used it yet.
“It’s been great actually, I probably didn’t pack the right clothes, jeans and sweaters.
“It’s gorgeous, it’s lovely, God bless Dublin, and God bless Ireland.
“May the beautiful weather continue, and you can all get a nice tan like me.
However, Marie Jeppsson Smith, who is visiting Dublin from Sweden, said the weather was “too hot” for her.
“It’s too hot for me, I’d prefer it cooler,” she said.
When asked whether the heat worries her, she added: “Yes, it does. The environment is very important to me.
“In the evenings it can be quite nice, but in a heatwave like this, it can still be too hot in the evenings. And I’ve noticed so many people actually go indoors and have their meals inside instead of sitting outside in the sun.”
It comes after Ireland recorded its hottest temperature in more than a century as parts of Dublin reached 33 degrees, according to Met Eireann.
Data from Met Eireann shows that temperatures soared to 33 degress at Phoenix Park in the capital on Monday, making it provisionally the hottest day ever recorded in July.
It also breaks the high temperature record for the 21st and 20th century.
⛈️Potential for heavy rainfall
☔️Some localised flooding
Valid until 21:00 this evening https://t.co/xodzAgzN2t
— Met Éireann (@MetEireann) July 19, 2022