The Met Office has issued a yellow alert for Sunday, warning of extreme high temperatures with the thermometer set to hit 40 C inland.
Temperatures are forecast to remain above average for the time of year through to Wednesday.
The yellow alert is in force from 11.00 am to 5. 00 pm with the Met Office saying some health risks amongst vulnerable people e.g. the elderly and very young are possible.
In its weather forecast, the Met Office said the weather will be mainly fine with risk of low cloud and local mist overnight and in the morning.
Temperatures on Sunday will be 40 C inland, around 32 on the west coast, 35 on remaining coasts and 30 in the mountains.
Monday, Tuesday and Wednesday will remain at the same levels which is above the average for the time of year, it added.
