Temperatures on Friday are expected to be around 39C inland, 31C on the west coast, 34C on the southern and eastern coastline and a cooler 30C in the higher mountains, the met office said.
On Friday night they will drop to around 22C inland and on the coast and 18C degrees in the higher mountains.
Over the weekend and Monday, the weather will be mainly clear, however there will be some increased cloud cover that could result in rain on Sunday and Monday in the mountains.
Elsewhere, the weather will be the same with temperatures above the seasonal average with possibly a very slight drop by Monday.
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