The forecaster said Mount Dillon saw the mercury rise to 27.1 degrees, with the fine weather expected to last well into next week.
A warm night is also on the cards, with temperatures due to stay above 13-16 degrees. Saturday will start off misty in some areas, but will quickly clear, bringing plenty of blue skies and sunshine around the country.
Today has been the hottest day of the year 🌡️
We have reached 27.1°C at Mt Dillon in Roscommon, which easily beats the previous highest temp of 25.6°C at the Phoenix Park on June 13th ☀️
— Met Éireann (@MetEireann) July 16, 2021
As people flock to the beach, the RNLI are urging members of the public to be careful around water.
While temperatures on land may soar over the coming days, water temperatures will remain low, so swimmers are being reminded to take particular care.