Seasonal low pressure is affecting the area and Monday will be mainly fine although clouds that develop in the afternoon in the mountains and inland may lead to isolated showers on thunderstorms.
Temperatures will rise to 39 C inland, around 31 on the west coast and in the mountains and around 32 C on the remaining coasts.
Tonight will be mainly fine with low cloud and patchy fog. Temperatures will fall to 22 C inland and on the east and south coasts, around 20 C on the remaining coasts and around 18 C in the mountains.
Tuesday will be mainly fine, although there will localised low cloud or patchy fog in the morning which will gradually lift.
In the afternoon clouds that form in the mountains and inland are expected to lead to isolated showers or thunderstorms.
Wednesday and Thursday will be mainly fine, while in the afternoon of Wednesday there will be increased cloud, mainly in the mountains.
Temperatures will edge down on Tuesday to close to average for the time of year, rising again on Wednesday and Thursday to a little above average for the time of year, at least inland and in the mountains.