Seasonal low pressure is affecting the area.
Friday will be mainly fine although local patchy cloud is expected at midday and in the afternoon which in the south east may lead to scattered showers, with the possibility of thunderstorms.
Temperatures will be 38 C inland, around 32 C on the south, east and north coasts, around 30 C on the west coast and around 29 C in the mountains.
Tonight will be mainly fine, with intervals of increased low cloud on the west and north coasts. Light fog is possible early in the morning.
Temperatures will fall to 22 C inland and on the north coasts, around 23 C on the remaining coasts and around 17 C in the mountains.
Saturday will be mainly fine but increased local cloud at noon and in the afternoon will lead to scattered showers and/or thunderstorms in the mountains and in some areas inland and on the southeast coasts.
Sunday and Monday will be mainly fine but increased local cloud, mainly in the mountains and in the southeast, may lead to scattered showers after midday.
Temperatures will edge down on Saturday, remaining at the same levels on Sunday and Monday to close to average for the time of year.