Irish Water says "restrictions will become unavoidable" amid continuing high demand for water in the Dublin area
Temperatures are forecast to hit 30 degrees in many parts of the country today as the heatwave continues.
Met Éireann has said it will hot during the afternoon, with temperatures of 26 to 30 degrees Celsius.
Inland areas are expected to be warmer, with sea breezes set to keep temperatures in the low-20s near southern and eastern coasts.
Met Éireann's Joan Blackburn explained it will be particularly hot over the western parts of the country.
She said: "Over parts of Connacht and west Munster, we'll see temperatures of about 30 degrees.
"Generally sunny conditions in most places - a bit of high cloud in southern counties at times... but really warm anywhere."
She added: "[We'll likely see similar temperatures] up until and inclusive of Friday. It looks like over the weekend maybe turning a little bit cloudier, [with] the temperatures falling back a little bit."
The continuing heatwave has led to a number of concerns, and a red warning has been issued for forest fires this week.
Irish Water, meanwhile, has said demand for water has 'risen to concerning levels' in the Greater Dublin area.
The utility has warned the public that water restrictions will become unavoidable.
The organisation is calling for people to conserve water in a bid to minimise the risk of restrictions.
Irish Water's Kate Gannon said: “If demand does not decrease we will start to see homes and businesses on the edge of the network in the Greater Dublin Area experience shortages, as happened in Skerries in recent weeks.
"The longer this continues, the more people will be at risk of shortages and outages.”
The utility's Drought Management Team is set to meet again today to monitor the situation.