The nation is set to bask in "glorious sunshine" for the coming days - but make the most of it while you can.
There will be highs of up to 20C in parts of the country today, making it the warmest day since April's mini-heatwave.
But forecasters say the sunny weather will be fading by the weekend.
Met Éireann's Willemien Phelan said the mercury would continue to creep up as the week goes on. But she warned that temperatures would fall again on Saturday and Sunday.
"The good news is we will see some more glorious sunshine until Friday," said Ms Phelan. "The west will see the best of the weather where temperatures are expected to reach the low twenties.
"The east coast will be slightly cooler due to a slight breeze but we can still expect highs of up to 20C, so summer is on its way.
"The sun is quite strong and the UV index is high. So those who are prone to sunburn should be ready with the suncream."
Hayfever suffers should also expect a bout of summer misery with a high pollen count expected nationwide.