Watch out if you're on the roads today.
There's a warning for thunderstorms and some spot flooding across the country.
A status yellow alert comes into force at 9am and will remain in place until 10 tonight.
Met Eireann says there could be extremely heavy rainfall in places, with up to 50 millimetres falling in a short space of time.
Meanwhile in Britain, Ryanair's had to cancel a small number of flights because of bad weather conditions around Stansted Airport.
The airline says some other services are also delayed.
South west England has been severely affected by torrential rain and thunderstorms.