It is "definitely time for sunscreen" this weekend, Met Éireann has said, with temperatures of between 23C and 24C forecast.
The highest temperature recorded yesterday was 23.9C at Cork Airport, while the mercury climbed to 23.4C at Johnstown Castle in Co Wexford.
However, Thursday remains the hottest day of the year so far, with a high of 25.1C recorded.
Meteorologist Paul Downes said that tomorrow "does look like it could possibly beat that".
He said that the exact figures forecast for tomorrow are "pulling back in the last while," but it is still expected to reach between 23C and 24C in the midlands tomorrow.
"I would not be surprised to see that go into higher figures, 25C and possibly even 26C there on Sunday and Monday looks quite similar, maybe over towards Dublin having a better chance of getting 25C, or possibly even a bit higher as well," Mr Downes said.
With temperatures on the rise the general, advice regarding sun exposure applies.
He said the UV rays will be moderate to high in parts of the country, particularly in the southeast, adding that it is "definitely time for sunscreen".
Munster is expected to see the most sunshine today, with more cloud in store for the northwest.
As for a more detailed look at what is in store for today, Mr Downes said there's "quite a bit of cloud about" this morning.
"There's a couple of brighter spells there over Munster and south Leinster and they will gradually extend across much of the country through the middle of the day and the early afternoon," he added.
"Now, unfortunately in the northwest, it looks like it is holding on to some clouds near northwestern fringes today, so the greatest chance there of some patchy misty, drizzle, continuing there at times.
"Elsewhere though, warm, sunny spells through the afternoon and temperatures getting up to 16C to about 24C
"Western and northwestern fringes are just a little bit cooler, but the rest getting up quite warm. Munster looks like the warmest part today and the winds would be quite nice, north and northwest."
