The met office has issued an extreme high temperature warning for Sunday saying temperatures inland are expected to hit a maximum of around 40 C.
The yellow alert is in force from 11 am to 4 pm.
“Be aware that high temperatures are expected. Some health risks amongst vulnerable people e.g. the elderly and very young are possible,” it said.
In its early morning weather bulletin, the met office said a seasonal low pressure is affecting the area.
Sunday will be mainly fine and temperatures will rise to 40 C inland, around 34 C on the south and east coasts, around 32 C on the remaining coasts and around 30 C in the mountains.
Tonight will be mainly fine, with the possibility of low cloud at dawn.
Temperatures will fall to 24 C inland and on the south and east coasts, around 22 C on the west and north coasts and around 18 C in the mountains.
Monday, Tuesday and Wednesday will be mainly fine with temperatures expected to remain a little above average for the time of year.