Dust levels in the atmosphere were slightly up on Wednesday and are expected to worsen by Friday, the met office said.
On Wednesday the weather is expected to remain sunny with some clouds by afternoon with isolated showers in the mountains and inland.
Temperatures will rise to 33C inland, around 30C to the west and north coasts, 28C on the southern and eastern coasts and 22C in the mountains.
On Wednesday night temperatures will drop to 19C inland, around 20 on the coast and at 16C in the mountains.
On Thursday, Friday and Saturday the weather will be mostly sunny, but with higher cloud coverage, increased dust and isolated showers in the afternoon, especially in the mountains.
Temperatures will gradually increase slightly on Thursday and Friday and fall again on Saturday.