The met office has issued an extreme high temperature warning for Saturday saying that the maximum temperature inland is expected to reach around 40 C inland.
The yellow alert is in force from 12 noon to 5 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 weather bulletin for Saturday, the met office said seasonal low pressure is affecting the area.
Saturday will be mainly fine, but increased local cloud is expected from midday on, mainly in the mountains.
Temperatures will rise to 40 C inland, around 34 C on the south and east coasts, around 32 C on the remaining coasts and 30 C in the mountains.
Tonight will be mainly fine. Locally at dawn, there may be patchy fog or low cloud.
Temperatures will fall to 21 C inland, around 20 C on the west coast, around 23 C on the remaining coasts and 18 C in the mountains.
Sunday, Monday and Tuesday will be mainly fine, although there will be increased local cloud from midday on in the mountains.
Scattered showers are possible at around midday on Sunday.
Temperatures are expected to remain at the same levels, which are a little above average for the time of year.