A Status Yellow High Temperature Warning will come into affect at 11am today for a number of counties, including Leitrim and Cavan
Temperatures in excess of 27 degrees are expected in places today.
The temperature warning will be valid until 9pm.
The AA is warning that tar on the roads may become slick and can be a hazard for motorists, with secondary roads most likely to be affected.
Most councils will treat this issue by sprinkling and rolling fresh chippings on the road surface.