Thursday will be mainly fine, though clouds that will gather in the evening may lead to isolated showers, mainly in the mountains and inland.
Temperatures will be 36 C inland, around 30 C on the coasts and 25 C in the mountains.
Friday will start off with increased localised clouds, in the west and north which may lead to isolated showers.
The rest of the country will start off fine but increased clouds may give way to localised showers or storms. Temperatures are expected to fall below the average for this time of year.
Temperatures will edge up gradually during the weekend, to reach the average for the time of year.