Temperatures in Louth, Meath, Dublin, Wicklow and Kildare are currently in the mid to late 20s.
People are advised to use plenty of sun block, wear hats and use sunglasses when driving. People are also asked to keep an eye on their elderly neighbours.
Animal owners are asked to make sure their pets have plenty of water and that they have a window open if their pet is traveling with them in their car.