All of Leinster and Tipperary are included in the warning.
Met Éireann has issued a high temperature warning for all of Leinster and County Tipperary, as very warm and humid conditions return this week.
The status yellow warning is in place from 6am tomorrow to 6am on Friday and will be in place for Laois, Offaly and Westmeath.
The forecaster is warning of temperatures above 27 degrees, and minimum nighttime temperatures of over 15 degrees.
It says it could lead to water safety issues, uncomfortable sleeping conditions, heat stress and animal welfare issues.
Meteorologist with Met Éireann, Rebecca Cantwell says the warm weather isn't expected to last beyond Friday:
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