A warm air mass is affecting the area.
Thursday will be mainly fine but from midday on there will be increased cloud that may lead to scattered showers or isolated thunderstorms, mainly in the mountains and inland.
Temperatures will rise to 39 C inland, around 32 C on the west coast, around 34 C on the remaining coast and around 30 C in the mountains.
Tonight will be mainly fine with the possibility of patchy fog or low cloud at dawn.
Temperatures will fall to around 22 C inland and on the north and west coasts, around 24 C on the remaining coasts and 18 C in the mountains.
Friday and the weekend will be mainly fine although increased low cloud from midday on may lead to scattered showers or isolated thunderstorms, mainly in the mountains and inland.
Temperatures will remain at the same levels over the next three days which is slightly above average for the time of year.