The Met Office has issued a yellow weather warning for Monday as high temperatures are again forecast.
The warning will be in place from 11am until 5pm with maximum temperatures expected to reach 42C inland and 32C in the mountains.
A warning was also issued for Sunday night, in place from 9pm to 7am on Monday, when the minimum temperature inland is not expected to fall below 28C.
Meanwhile, on Monday the danger for a fire breaking out is again at the red level,
Lighting fires in unallowed areas can end up with a 10-year jail sentence or a fine of €50,000.
