A hot air mass is affecting the area, bringing temperatures of 41 C inland on Wednesday and remaining above average for the time of year until Saturday.
The met office has already issued an extreme high temperature warning for today, from 11 am to 4 pm and warned that some health risks among vulnerable people such as the elderly and very young are possible.
Wednesday will be mainly fine, although there will be intervals of increased high cloud from noon on. Light dust in the atmosphere is possible.
Temperatures will rise to 41 C inland, 36 C on the south and east coasts and 30 C on the remaining coasts and in the mountains.
Tonight will be mainly fine although there may be increased high cloud at intervals. Temperatures will drop to 22 C inland, the south and east coasts and around 20 C in the west and north as well as in the mountains.
Thursday, Friday and Saturday will be mainly fine although there will be intervals of high cloud. There will be light dust in the atmosphere until Friday.
Temperatures are expected to remain at the same levels on Thursday and Friday at noticeably higher than average for the time of year.
They will edge down on Saturday, but will remain above average.