A warm air mass is affecting the area and there will be dust in the atmosphere, with concentrations rising at intervals, the met office said in its early morning weather bulletin.
Tuesday will be mainly fine with some higher cloud at intervals. Temperatures will be 36 C inland, around 31 C on the south and east coasts and around 28 C on the remaining coasts and the mountains.
Tonight will be mainly fine, with increased higher cloud at intervals. There may be localised low cloud or fog. Temperatures will fall to 18 C inland and on the coast and around 16 C in the mountains.
Wednesday, Thursday and Friday will be mainly fine, with intervals of increased cloud.
Temperatures will edge up until Thursday, remaining at the same levels on Friday which are noticeably higher above average for the time of year.