A Status Yellow thunderstorm warning has been issued for several parts of the country as temperatures remain very high.
The warning for Connacht, as well as counties Cavan, Donegal, Monaghan, Clare, Tipperary, Kildare, Laois, Longford, Meath, Offaly and Westmeath is due to come into effect at 9am and will remain in place until 6pm.
Met Éireann is warning of localised flooding, difficult travelling conditions and possible damage to utilities including power, water, gas, and telecommunications.
A high temperature warning for the entire country remains in place until 9am.
Lightning visible off Bundoran in Co Donegal
Met Éireann said the high temperature warning includes water safety concerns, due to increased use of lakes and beaches, uncomfortable sleeping conditions, heat stress, and possible forest fires.
People are being urged to keep hydrated, stay out of the sun during the hottest part of the day, avoid strenuous activity, and not to leave people and animals unattended in vehicles for any period of time.
Yesterday, a temperature of 32.1C was recorded at a weather station in Athenry, Co Galway.
Met Éireann said it was a record high for the station and that other stations across the country also broke their own records.
A Status Yellow thunderstorm warning is also in place for all counties in Northern Ireland until 10am.
The UK Met Office said heavy showers may bring disruption to some areas this morning.