As the heatwave continues, Munster and Leinster can expect things to heat up even more from Thursday.
Met Éireann has issued a status yellow high-temperature warning for the two provinces.
It will come into effect on Thursday at midday and will remain in place until 6am on Sunday morning.
Over the three days, people can expect maximum temperatures of around 27C to 29C.
There will be little relief felt during the nights as the mercury will not dip below 15C.
Coastal areas may not feel as hot due to sea breezes but care should still be taken when outside in the sun.
Linda Hughes from Met Éireann has said it is unlikely that this warning will be upgraded any higher but some counties - particularly in south Connaught - could be added at a later point.
A weather advisory is currently in place for the entire country and will remain in effect until midnight on Monday.
Today, the south and east have had the hottest of the sunshine with temperatures of up to 26C. Tonight will be much cooler with temperatures ranging between 7C and 12C.
Wednesday marks the beginning of the hot spell predicted by Met Éireann. It will be warm, dry and sunny with some light breezes.
Some areas in Munster and Leinster will see the heat rise to 27C and 28C while it will be slightly cooler in other parts of the country.
It will get hotter again on Friday with highs of 29C forecasts with the odd stray shower possible here and there.
The high pressure will continue to bring hot and dry conditions through the rest of the week and into the weekend with temperatures widely in the mid to high 20s.
Over the weekend, there is a possibility of thundery showers breaking out in some areas.
Nights will remain uncomfortably warm generally staying above 16C to 17C.
Current indications suggest that next week will turn more unsettled with temperatures returning to the average for the time of year.
Meanwhile, Irish Water has warned that it is watching closely to see if water restrictions will be needed as the hot spell continues.
Areas of Clonakilty will experience an overnight water restriction from 11pm tonight until 7am tomorrow morning.
Interventions are currently underway at 13 water supplies to ensure that they do not run dry, while 60 others across Ireland are on a watch list amid concern they will reach critical levels and may need to be restricted.
The utility is anticipating that while hot weather causes water levels to drop, demand will also increase. Tom Cuddy, the head of operations at Irish Water, said they are hoping they will not have to take actions that will impact on their customers.
The public is urged to take care during the hot spell as UV levels will be high, especially under clear skies.
There will be a risk of heat stress, particularly among the more vulnerable in our communities.
Mr Ruth cautioned the public to look out for the elderly and the vulnerable and also urged people to wear sunscreen, to stay hydrated, to exercise caution when near water and to take care when using barbeques.
People are advised to wear appropriate clothing, seek shade during the hottest part of the day (between 11am and 3pm), wear sunglasses, and wear suitable SPF.
Adults are recommended to apply at least SPF 30 while children should be given SPF 50.
Those seeking to cool off by heading to the beach are reminded to respect the water.
If swimming, do so on a lifeguarded beach and do not go to secluded areas or places where it will be difficult to spot you.
Young children should not use inflatable toys in the sea as they can rapidly be swept away from the shore.
Kevin Rahill, RNLI water safety lead, said people should tell someone where you are going and what time you will be back.
"If you get into trouble in the water, float to live: lean back, using your arms and legs to stay afloat. Control your breathing, then call for help or swim to safety," he said.
"For those going afloat, wear a lifejacket or personal flotation device, and carry a reliable means of raising the alarm such as a VHF radio or mobile phone.
"Go prepared by checking the weather forecast and tide times, tell someone where you are going and what time you will be back, and importantly, what to do if you do not arrive back on time.
"Should you get into difficulty or see someone else in trouble, dial 999 or 112 and ask for the Coast Guard."