Seasonal low pressure is affecting the area.
Tuesday will be mainly fine, although there will be increased cloud in the mountains in the afternoon.
Temperatures will rise to 36 C inland, around 32 C on the south and east coasts, around 30 C on the west and north coasts and 27 C in the mountains.
Tonight will be mainly fine. Temperatures will fall to 22 C inland and on the coasts and 15 C in the mountains.
Wednesday, Thursday and Friday will be mainly fine with increased cloud at intervals, mainly in the mountains.
Temperatures will edge up to above average for the time of year.