Met Eireann has issued an urgent warning as temperatures are set to jump to a scorching 30C.
A Status Yellow High Temperature alert is in place from 1 pm today until 9 am on Friday.
The warning reads: "High temperatures continuing this week with hot conditions by day and staying very warm and humid at night.
"Daytime maximum temperatures generally 27 to 30 degrees Celsius with overnight values not falling below 17 to 20 degrees."
Today is going to be hot and sunny with temperatures reaching 22 on the coast in a light onshore breeze, to 26 degrees inland.
It will be warm and humid tonight with temperatures not falling below 15 or 16 degrees.
Dry, hot, and mostly sunny weather is expected tomorrow with the highs of 25 to 28 degrees, a little less warm along the coast in a light southeast breeze.
